Yet Another Cycling Forum

Random Musings => DIY => Skip Bike and Bodge It => Topic started by: DuncanM on 19 December, 2015, 09:16:39 pm

Title: Recumbent trike (hopefully folding)
Post by: DuncanM on 19 December, 2015, 09:16:39 pm
I've wanted a Windcheetah ever since I saw one in the Richards Bicycle book aged 10 or something!
Then at the start of this year I discovered AtomicZombie, and started on the process of building a StreetFox (but with disk brakes, 20" rear wheel, and a few extra modifications, including a fold in the middle). This isn't necessarily a "bodge", but there are a few along the way! I'll update this thread with my progress so far - I've not completed it yet, but I've made a lot of progress!
This is what it's supposed to look like when done:
(http://www.atomiczombie.com/plans/streetfox/StreetFox%20Suspension%20Tadpole%20Trike%201.jpg)

This is what I started with - the bikes in the top photo were knackered and free, but the suspension bike cost a whole £15:
(https://farm8.staticflickr.com/7548/16278942981_683e630423_c.jpg) (https://flic.kr/p/qNvQAH)20150114_185607 (https://flic.kr/p/qNvQAH) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
(https://farm8.staticflickr.com/7473/16310893815_43542cf1bd_c.jpg) (https://flic.kr/p/qRkAta)20150118_183431 (https://flic.kr/p/qRkAta) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

So, off came the rear triangle - this will be used almost entirely as is.
(https://farm9.staticflickr.com/8620/16329093006_10d38c3c72_c.jpg) (https://flic.kr/p/qSWSsj)20150124_124346 (https://flic.kr/p/qSWSsj) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
But the rest of the frames didn't survive so unscathed - here are the headtubes and the pivot for the rear triangle (angle grinders are great!):
(https://farm9.staticflickr.com/8594/16354177622_3874d3b06e_c.jpg) (https://flic.kr/p/qVareG)20150124_141729 (https://flic.kr/p/qVareG) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
And here they are all cleaned up with the chopped up forks to go with them:
(https://farm9.staticflickr.com/8610/16363960025_13b478e053_c.jpg) (https://flic.kr/p/qW2zcP)20150125_135603 (https://flic.kr/p/qW2zcP) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
At this point, I decided (don't know why) that I needed significantly more travel than could be provided by the crappy shock that was on the kids bike, so this arrived:
(https://farm9.staticflickr.com/8616/15735763363_9c35506454_c.jpg) (https://flic.kr/p/pYvUdT)20150124_160615 (https://flic.kr/p/pYvUdT) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

And then it was time to do more than buy things and chop them up!
More to come......
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 19 December, 2015, 09:35:02 pm
I also got myself some BMX wheels for the front ones - lots of spokes, 14mm axles to stop them bending when held on one side, and both rear wheels so I can screw a brake disk adapter on.
(https://farm8.staticflickr.com/7299/16382933235_cd42d985dc_c.jpg) (https://flic.kr/p/qXGPh8)20150127_183729 (https://flic.kr/p/qXGPh8) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Box section steel - 1.6mm wall, 40mm square. I got 6m, and I think it was about 40 quid! I ended up using a little under 3m, so I've got enough to make another if I want! I used a holesaw to cut the end of this one so that I can weld in the pivot for the rear triangle. Originally I actually just made a hole with steel at the end so it was extra sturdy, but when I put the pivot point in the hole I didn't have enough clearance at the back for the triangle to attach! So I binned that idea and just did it the way the plans said, relying on the welds to hold...
(https://farm9.staticflickr.com/8661/16601121582_be9aa6ffa4_c.jpg) (https://flic.kr/p/rhZ65b)20150221_105332 (https://flic.kr/p/rhZ65b) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Held in place so that it can be welded in properly...
(https://farm9.staticflickr.com/8643/16415891789_eee1ea11e6_c.jpg) (https://flic.kr/p/r1BJH4)20150221_105420 (https://flic.kr/p/r1BJH4) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Ugly (but sturdy) welding:
(https://farm8.staticflickr.com/7336/16600558771_c69a46b12e_c.jpg) (https://flic.kr/p/rhWcLx)20150221_115344 (https://flic.kr/p/rhWcLx) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
(https://farm8.staticflickr.com/7433/16575811736_645c0011be_c.jpg) (https://flic.kr/p/rfKnkw)20150221_120606 (https://flic.kr/p/rfKnkw) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Cleaned up a bit on the grinder:
(https://farm9.staticflickr.com/8597/16601264002_32539b0aea_c.jpg) (https://flic.kr/p/rhZPpG)20150221_121715 (https://flic.kr/p/rhZPpG) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Here's the suspension mounting plates that I chopped off the donor bike:
(https://farm9.staticflickr.com/8595/15991499624_4c0cc29a8d_c.jpg) (https://flic.kr/p/qn7BGL)20150222_162303 (https://flic.kr/p/qn7BGL) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Then they got welded on (after guessing exactly where they should go so that the seat back wouldn't foul he shock)
(https://farm9.staticflickr.com/8682/16673454075_b5ee4259f5_c.jpg) (https://flic.kr/p/rpnP18)20150228_165219 (https://flic.kr/p/rpnP18) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
And here's them and the pivot point in use.
(https://farm9.staticflickr.com/8586/16485883228_768de63f08_c.jpg) (https://flic.kr/p/r7NsJ1)20150228_170658 (https://flic.kr/p/r7NsJ1) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
This was all done by the end of February, so that was actually reasonable progress so far. Then things slowed down a bit...
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 19 December, 2015, 09:59:08 pm
The next bit of the process is to create and attach the backrest:
(https://farm9.staticflickr.com/8659/16498068619_75339c6b79_c.jpg) (https://flic.kr/p/r8SV1X)20150301_161152 (https://flic.kr/p/r8SV1X) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

At this point I realised that the threads on my wheels would be rotating in opposite directions, so if I attached a screw on brake disk mount to the right hand one it would unscrew whenever I tried to brake! After a little thought I figured I'd just bolt the screw on addapter to the hub, so I drilled these holes:
(https://farm9.staticflickr.com/8710/16770925389_c64b9b5563_c.jpg) (https://flic.kr/p/rxZnQ2)20150328_144304 (https://flic.kr/p/rxZnQ2) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
And bolted the disk and screw on adapter through them:
(https://farm9.staticflickr.com/8685/16770927359_f41bdf6716_c.jpg) (https://flic.kr/p/rxZopZ)20150328_172102 (https://flic.kr/p/rxZopZ) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
I wasn't convinced that this would be effective, but it's been done on other AZ trikes, and apparently it works. There's some threadlock on the threads, and it's done up really tight, so this is more belt and braces than seriously stressed bolts, but we'll have to wait and see how well it stays put...
I also got some 15mm (x 50m) bar, and then drilled 14mm holes for the axles to go through:
(https://farm9.staticflickr.com/8653/16647505546_72fd31ba17_c.jpg) (https://flic.kr/p/rn5PpG)20150228_165118 (https://flic.kr/p/rn5PpG) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Here's the practise go I had at welding the spare one onto a chopped  remnant of the fork crown.  This bit was quite tricky to get the angle good, and also it's a really stressed weld, between a 15mm bar and a pretty chunky bike part (the wall sizes were probably 5mm thick). I turned the welder up to power setting of 7 (out of 8), and bashed the hell out of the test piece. I managed to hold the bar in the vice and hit the fork crown so hard that I bent the 15mm thick bar (without breaking the weld)!
(https://farm9.staticflickr.com/8655/16603685397_3cdd7f9b92_c.jpg) (https://flic.kr/p/ridecT)20150314_122412 (https://flic.kr/p/ridecT) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
More to come in a bit when my laptop is charged!
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: Wobbly John on 19 December, 2015, 10:26:32 pm
 :thumbsup:
Title: Re: Recumbent trike (hopefully folding)
Post by: woollypigs on 19 December, 2015, 11:25:32 pm
This looks fun :)
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 19 December, 2015, 11:55:45 pm
Thanks guys. :)
Battery charged, on with the story...

After a couple of months break, I started on the cross boom. This is where those head-tubes you saw earlier ended up. I used the holesaw again to get the right camber and caster angles. Before chopping out the ends of the tube, it looked like this (note industrial MIG welder and crap pillar drill in the background):
(https://farm9.staticflickr.com/8782/17367873122_a9b068d393_c.jpg) (https://flic.kr/p/ssJTAj)20150504_162902 (https://flic.kr/p/ssJTAj) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

With the headtube balanced in the right place it looked like this:
(https://farm9.staticflickr.com/8781/17182020278_14dee08af7_c.jpg) (https://flic.kr/p/sbjm1W)20150504_165356 (https://flic.kr/p/sbjm1W) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

And then finally welded up and cleaned up with the flap disk, it looked like this:
(https://farm1.staticflickr.com/757/21137010173_1d07d0dd7e_c.jpg) (https://flic.kr/p/ycNGHT)2015-09-27_04-00-53 (https://flic.kr/p/ycNGHT) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
At the point where I'd done this on both sides, I discovered something really irritating - when I had been welding the headtubes on I'd fired a couple of bits of welding wire straight through the gap, and now there was something rattling around inside the tube, and there was no hole to get it back out of! After much thought I drilled a small hole in the middle of the boom, and tried to magnet the rattly bits out.  That failed dismally!  :( Eventually, I got some double sided tape and stuffed it through the hole - shook the tube up and down a lot, and managed to capture the loose bits on the tape! they even came out of the hole again afterwards! :)

Then there was a big gap where I got sidetracked into other projects like constructing a set of replica Roman auxilliary shields (that's another thread entirely!). Eventually, I got back to this and realised I had to work out where the boom should live. I couldn't follow the plans, because they call for a v shaped boom, but I'd decided a straight one would be easier! :) (And also because I figured it would create more of a compact shape if folded.)
So I mocked it up and experimented a bit:
(https://farm6.staticflickr.com/5763/21758038925_823c4e8a78_c.jpg) (https://flic.kr/p/z9FCWa)2015-09-27_04-01-26 (https://flic.kr/p/z9FCWa) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

When I'd finally decided it was good I tacked it and welded it in place.  As you can see, my welding is getting better:
(https://farm6.staticflickr.com/5658/22104757101_aba744e368_c.jpg) (https://flic.kr/p/zFjEaK)2015-10-11_06-38-00 (https://flic.kr/p/zFjEaK) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I'm still not 100% sure the boom is in the right place, so I'm not going to add any extra re-enforcing gussets until I've ridden it and made sure the backs of my legs don't clobber it where it is! I added seat mounts next - that was relatively straightforward:
(https://farm6.staticflickr.com/5790/22086443101_11eb48f224_c.jpg) (https://flic.kr/p/zDGN48)2015-10-10_08-13-47 (https://flic.kr/p/zDGN48) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
and then ground the welds flat so that the seat base would sit properly:
(https://farm6.staticflickr.com/5633/21473582793_d5d2d6f22c_c.jpg) (https://flic.kr/p/yHxJ36)2015-10-11_06-37-08 (https://flic.kr/p/yHxJ36) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Finally, with the frame in reasonable shape, I used a nylon clean and strip disk to remove all the surface rust, and brushed some grey primer on to stop it coming back (another unusual use for a toe-strap - I should add it to the list on that other thread!):
(https://farm1.staticflickr.com/770/22097425725_ef36c1b943_c.jpg) (https://flic.kr/p/zEF5NH)2015-10-11_09-27-48 (https://flic.kr/p/zEF5NH) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

That brings us up to the start of December, but I've made some progress this month again, so I'll have to add that tomorrow...
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: clarion on 20 December, 2015, 10:03:36 am
Looking good so far.  Keep us posted!
Title: Re: Recumbent trike (hopefully folding)
Post by: Torslanda on 20 December, 2015, 02:42:28 pm
Homebuilding is fun! Redshift got me AZ's book many years ago. (It could've been my 40th birthday.) Reading it showed us what we got wrong when building my first recumbent and allowed me to refine (really?) the design (and that's not the right word, either!) and ended up with this . . .

(http://i33.photobucket.com/albums/d55/shedbike/johnsbike.jpg)

Haven't yet attempted a trike. Way too much going on with castor/camber and Ackerman/centrepoint besides having to make the right side mirror the left . . .

PS If you still find yourself wanting a Windcheetah, I've got one for sale . . .

(http://i33.photobucket.com/albums/d55/shedbike/WP_000578_zps695b6736.jpg)
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 20 December, 2015, 05:21:41 pm
I don't have the book - I just bought a pack of 6 plans for $36. I'd love a Windcheetah, but I fear it's about a grand more than I can afford! I've sent you a PM just to confirm. I've never even ridden a recumbent or a trike, so it's a bit of a step in the dark!

Anyway, back to the story. I got hold of a crappy folding bike, and then I chopped it up for bits:
(https://farm8.staticflickr.com/7799/16749545633_9cb41dd0bd_c.jpg) (https://flic.kr/p/rw6Nnx)20150504_174943 (https://flic.kr/p/rw6Nnx) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I eventually got around to sticking the front wheels on, so it ended up on it's own wheels like so:
(https://farm1.staticflickr.com/720/22428024071_620d1e0a07_c.jpg) (https://flic.kr/p/AaTubc)2015-10-23_08-56-30 (https://flic.kr/p/AaTubc) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
(https://farm1.staticflickr.com/684/22417166425_bb16beca6d_c.jpg) (https://flic.kr/p/A9VQzp)2015-10-23_08-56-46 (https://flic.kr/p/A9VQzp) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I had some 3mm plywood hanging about, so I cut out a couple of pieces and bonded them together for the seats: (https://farm1.staticflickr.com/575/22679513285_9b69428a37_c.jpg) (https://flic.kr/p/Ay7ra8)2015-11-01_05-07-27 (https://flic.kr/p/Ay7ra8) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Then I drilled holes and put T nuts in and screwed them to the frame to see how it would work. Followed by some CAD (cardboard aided design) to see how the fold would work if it folded over the top like an ICE trike.
(https://farm1.staticflickr.com/618/23574767382_284086a683_c.jpg) (https://flic.kr/p/BVdR1A)2015-12-11_09-51-37 (https://flic.kr/p/BVdR1A) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I've since thought that I might fold the back wheel underneath instead, because that would put the joint in compression rather than tension. It would also mean that I could put the pivot point where the seat meets the backrest, which is probably the point that would cause the shortest overall package. HP Velotechnic fold that way, and their fold looks very easy to do. I need to do some more CAD to see how that would actually work!

I got some foam from Hobbycraft and cut it to the right shape for the backrest and seat base:
(https://farm1.staticflickr.com/735/23228585230_de85386ed3_c.jpg) (https://flic.kr/p/BoCz7N)2015-12-04_10-09-17 (https://flic.kr/p/BoCz7N) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

And so I painted the bases:
(https://farm1.staticflickr.com/767/23676008036_560b798b9f_c.jpg) (https://flic.kr/p/C5aJk7)2015-12-12_05-55-08 (https://flic.kr/p/C5aJk7) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Last weekend I strapped the rear triangle to the back of my fixie and took it to the Broken Spoke Workshop to replace the bottom bracket (with a really short one that came with a Truvativ crankset)
(https://farm6.staticflickr.com/5666/23360052859_edab2731fa_c.jpg) (https://flic.kr/p/BAfnS4)2015-12-13_07-41-16 (https://flic.kr/p/BAfnS4) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

And now we're almost up-to-date - this weekend, I chopped the arm off the crankset so it will work properly as a jackshaft. I'm going to run the middle ring to the freewheel, and then the front chainset to the inside ring of the jackshaft.  Crankset mutilation:
(https://farm6.staticflickr.com/5741/23206270054_47a541a8cf_c.jpg) (https://flic.kr/p/BmEcAo)2015-12-18_10-07-27 (https://flic.kr/p/BmEcAo) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

(https://farm6.staticflickr.com/5637/23206272154_8351710071_c.jpg) (https://flic.kr/p/BmEddA)2015-12-18_10-07-38 (https://flic.kr/p/BmEddA) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Then I put the triangle back onto the bike, so that the rear end is essentially finished. After that, I stapled some vinyl over the seat foam - it's quite good on the top but pretty scraggly on the bottom. I figure I'll sort the bottom out once I've actually tried riding on it and I'm happy with how comfortable it is:
(https://farm1.staticflickr.com/602/23808298546_07a51759de_c.jpg) (https://flic.kr/p/CgRKFY)2015-12-18_10-07-52 (https://flic.kr/p/CgRKFY) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

And finally, I made the clamp bits to attach the front bottom bracket to the main boom (it moves along the boom to adjust for leg length).
(https://farm6.staticflickr.com/5708/23481871049_7df31536f5_c.jpg) (https://flic.kr/p/BM1JaF)2015-12-19_04-59-17 (https://flic.kr/p/BM1JaF) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Became this:
(https://farm1.staticflickr.com/620/23222989693_4fa10182c6_c.jpg) (https://flic.kr/p/Bo8TL2)2015-12-19_04-59-41 (https://flic.kr/p/Bo8TL2) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Became this:
(https://farm1.staticflickr.com/739/23767311481_f2690d8674_c.jpg) (https://flic.kr/p/CdeFEr)2015-12-19_04-59-53 (https://flic.kr/p/CdeFEr) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Now I need to weld the plates to the BB shell either side of the main beam and put bolts through to allow it to be clamped. I'm really frustrated that the bottom bracket I ordered hasn't turned up despite getting an email from Royal Mail saying that it had been delivered! >:( But I want to chase the threads in the BB shell before I install the bottom bracket properly (after I've done the welding), so I'll have to wait until the Broken Spoke is open again (I don't have my own BB thread tool).

So now I'm up-to-date.  I doubt much is going to happen over Christmas, but we'll have to see how it goes.
The remaining really difficult bit is welding on the brake/steering arms. They need to be parallel to the ground, and to the brake disks.  I've been putting that off, but there isn't much else left on the critical path to riding it!
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: Kim on 20 December, 2015, 05:58:04 pm
I've never even ridden a recumbent or a trike


This is made apparent by:

Quote
Then I put the triangle back onto the bike, so that the rear end is essentially finished. After that, I stapled some vinyl over the seat foam - it's quite good on the top but pretty scraggly on the bottom. I figure I'll sort the bottom out once I've actually tried riding on it and I'm happy with how comfortable it is:
(https://farm1.staticflickr.com/602/23808298546_07a51759de_c.jpg) (https://flic.kr/p/CgRKFY)2015-12-18_10-07-52 (https://flic.kr/p/CgRKFY) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Neat though it is, you're going to find that horrendously sweaty.  Especially if you do the whole seat in it.  But don't worry too much until you're happy with the rest of the trike, seats usually need a bit of tweaking anyway.

Pond filter foam seems to be a good cheapskate alternative to Ventisit.


*returns to watching with interest*   :thumbsup:
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 20 December, 2015, 06:09:28 pm
That's what the plans call for - I'm making enough changes to fundamentals that I'll stick with the plans for the rest if it makes life easier! It was super cheap, so if it gets binned at some point then that's fine.
*off to google ventesit*  ;)
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: mmmmartin on 21 December, 2015, 10:16:46 am
Astounding imagination, excellent skills, superb implementation. Was going to post pix of my efforts at adding a pocket and some reflective strips to turn a normal cycling gilet into Something To Amaze, but am now feeling completely outclassed and inadequate. I mean - getting metal to melt and stick to metal? I can't do that.
Title: Re: Recumbent trike (hopefully folding)
Post by: loadsabikes on 22 December, 2015, 03:19:48 pm
Great thread, just come across it.
Keep at it.
If you ever need any tube bending, especially 40 mm box, give me a shout, I have the necessary dies.
Title: Re: Recumbent trike (hopefully folding)
Post by: Von Broad on 22 December, 2015, 05:08:56 pm
Great to see somebody enthusing about home building. Your posts made me laugh though - all those old scrap bikes, pictures of saw off headsets, workmates, talk of angle grinders and some serious heavy duty mild steel tubing. I could almost smell the ground steel in the room and hear the buzz of that MIG welder going on [what are you using out of interest?] when I was reading your description. Takes me back.

I've never even ridden a recumbent or a trike, so it's a bit of a step in the dark!

That's what happened to me and I ended up building 11 of the damn things in the end! [Rode some respectable distances on a few of them too].

Looking forward to seeing the finished thing. It's looking tidy. Brad's put together some good bikes [I really liked his very first one, The Marauder (http://forum.atomiczombie.com/gallery/showimage.php?s=d5d37dae36bf794dbd22074532644ee3&i=87&c=12)]  and it's a good idea to work from plans that are known to work - you'll learn a lot and it will save a lot of messing about.
I'd be amazed if it's your last  :)
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 22 December, 2015, 08:19:54 pm
If you ever need any tube bending, especially 40 mm box, give me a shout, I have the necessary dies.
Thanks, I may take you up on that when I get to the next one! :)
The welder is one I got to try car restoration (ended up getting rid because it was far too large a project). It is a secondhand Murex Tradesmig I got from a welder repair guy. It weighs a ton, and the stitch functionality doesn't work, but it's solid and reliable and produces good welds. I've got a 3 year lease on a argoshield gas bottle as well.
(https://farm8.staticflickr.com/7018/6448283917_314f3fa748_z.jpg) (https://flic.kr/p/aPP99V)Welder (https://flic.kr/p/aPP99V) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
I taught myself to use it by trying and then posting on the migwelding forum and then trying again!
I'd like to learn TIG - I had a go on a car resto course I went on, and I've got a cheapass scratch start box, but it takes the tiny little Argon canisters and so it would cost a fortune to get good enough to use it.  I should just buy a lift start (or even an HF start) model with a proper adapter for a decent sized gas bottle, but that's real money, and eats into the project budget!
Not sure what the next one is going to be... :)
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 02 January, 2016, 11:02:47 pm
I added the bracing for the bottom bracket today.  The plates I had cut previously were too short, so I had to make some more. 40mm holesaw, angle grinder with a cutting disk and some 4mm sheet created this:
(https://farm6.staticflickr.com/5784/24099732756_89e26141af_z.jpg) (https://flic.kr/p/CHBqVJ)2016-01-02_01-57-08 (https://flic.kr/p/CHBqVJ) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I lined everything up thus:
(https://farm6.staticflickr.com/5769/23503523453_d71807dfe1_z.jpg) (https://flic.kr/p/BNVGEZ)2016-01-02_06-13-43 (https://flic.kr/p/BNVGEZ) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

and welded the plates onto the BB shell.
(https://farm2.staticflickr.com/1489/24022220382_76ff8071c5_z.jpg) (https://flic.kr/p/CALacu)2016-01-02_06-14-02 (https://flic.kr/p/CALacu) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
The welds were crappy and blobby because I forgot to clean the paint off the shell before tacking the plates on, but the joins seem pretty sturdy.  Maybe a little too sturdy - the cardboard I used to space my joint for welding clearly wasn't correctly placed and the front edge is a bit on the tight side! Still, nothing a bit of brute force and ignorance can't fix. I cleaned the welds p a bit, so it all looks a bit better now:
(https://farm2.staticflickr.com/1546/23503684914_950a5b963f_z.jpg) (https://flic.kr/p/BNWwEN)2016-01-02_07-47-22 (https://flic.kr/p/BNWwEN) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
(https://farm6.staticflickr.com/5639/23836252350_37186c591d_z.jpg) (https://flic.kr/p/Cjk2o7)2016-01-02_07-47-10 (https://flic.kr/p/Cjk2o7) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

All that remains is to mark it up and drill some holes for the bolts that go under the main boom. Oh, and recut the BB threads, so the BB can be trial fitted...
That would leave me with just the pulleys and tensioning to fix to have all my propulsion bits sorted - I really should get on with the steering/brake arms soon! :)
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 29 July, 2016, 09:39:36 pm
Progress on this today.  I cut and drilled some brake caliper mounts (2mm steel), some steering tabs (4mm steel - took forever to drill the holes!) and also drilled the holes in the bottom bracket assembly.
This is what all those bits actually look like:
(https://c4.staticflickr.com/9/8166/28633689955_5e27988ec8.jpg) (https://flic.kr/p/KCg9rz)2016-07-29_06-32-41 (https://flic.kr/p/KCg9rz) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Hopefully tomorrow I can weld them on - once that's done I'll only need to sort out the tie rod (and I've got the bits) before I can had an unpowered roll down the hill!  ;D
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 30 July, 2016, 06:14:04 pm
Much more progress today. I had originally cut out the brake supports according to my cardboard templates, but when I came to actually attach them with the brakes attached, I realised I had to modify them a bit! Still, I eventually fettled them until they fitted well enough and then I welded them up.  I then realised that the steering tab wouldn't fit in the right place on the right hand one, so I had to cut some extra out of the brake mount (not a problem - it was just a quarter of an inch on the end). After that, I measured it twice, and welded on the steering tabs.
(https://c4.staticflickr.com/9/8253/28037734163_efa975f28a.jpg) (https://flic.kr/p/JHAHxH)IMG_20160730_174924 (https://flic.kr/p/JHAHxH) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
The welding isn't quite as pretty as you would like (though some of it's not too bad), but it's strong enough:
(https://c4.staticflickr.com/9/8672/28037730603_611259f9cb.jpg) (https://flic.kr/p/JHAGuk)IMG_20160730_174939 (https://flic.kr/p/JHAGuk) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
(https://c2.staticflickr.com/9/8615/28037731233_a6ce72a109.jpg) (https://flic.kr/p/JHAGFc)IMG_20160730_174950 (https://flic.kr/p/JHAGFc) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Once I've made dinner (and these things have cooled down), I'm going to put these back into the frame and try to work out how long the tie bar needs to be - then I can weld on the bolts for the track rod ends. At which point, adding the wheels, the brakes, and the handlebars (oh yeah, and the seat back) will allow me to try a roll down test. :)
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 31 July, 2016, 06:39:02 pm
I've not managed to have my first ride (roll) on it yet. :(
However, I have made some real progress - the steering link bar is all welded up (including adding a squared off part in the middle that I can turn using a 13mm spanner to open/close it) and installed...
Plus the cranks and pedals are on. :)
Welding the nuts on the end of the steering rod is really helped by the groove in the workmate:
(https://c1.staticflickr.com/9/8706/28571325632_7884637110.jpg) (https://flic.kr/p/KwKvGC)IMG_20160731_152429 (https://flic.kr/p/KwKvGC) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
I think she needs to grow a bit:
(https://c6.staticflickr.com/9/8790/28677233685_f4890094d8.jpg) (https://flic.kr/p/KG7jtx)IMG_20160731_171159 (https://flic.kr/p/KG7jtx) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Waiting in the garage for the next session:
(https://c5.staticflickr.com/9/8729/28645521236_4eb5459b5d.jpg) (https://flic.kr/p/KDiMtb)IMG_20160731_173009 (https://flic.kr/p/KDiMtb) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Now for the downside - the reason I didn't get to ride it is because I couldn't fit the brakes.  Sure, I could slot the brakes over the disks and then bolt them on, but when I did that, the wheels wouldn't go round properly! Aside from needing shorter bolts (they hit the disks if I do them up fully), the alignment isn't quite there and the calipers rub on the edge of the disks.  I'll get some washers with the bolts, and I'll have to make the brake holes into slots. Once that's done, I should be able to roll.

The next steps are to get some chain (I reckon I need 3.45m or thereabouts), a (cheap) derailleur to put some tension into the return side, a chain tube, and a round groove pulley (so I can route the tensioned side). Oh, and some brake and gear cable for the rear mech/brake. I think that's all the pars I need to make it actually usable, and fitting them is mostly a matter of regular bike mechanics rather than complex recumbent engineering!
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: Peter on 01 August, 2016, 12:33:13 am
Duncan, this is fascinating!
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 13 August, 2016, 09:34:15 pm
As often with this build, 2 steps forward and some head scratching!
I got some chain and hosepipe last week, and the pulleys arrived in the post. Today I got some bolts, so I was in a position do get on with the trike again. :)
I have finally got my brakes into a reasonable position.  They both have a little intermittent rub, but I'm blaming that on the disks not being 100% round!  It'll be annoying if it stays like that, but for getting it on the road and testing it, I'll put up with it! :)
(https://c2.staticflickr.com/9/8638/28884284801_fbd9665a2c.jpg) (https://flic.kr/p/L1pvyn)IMG_20160813_203928 (https://flic.kr/p/L1pvyn) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
I also installed the pulley. I got some M10 bolts with shoulders on, and then I realised that I needed to space the pulley off the main boom. I cut down a piece of the 12mm tube I used for the steering rod and put it over the bolt as a sleeve. Then I worked out where it needed to go, and I welded it on. :)
(https://c2.staticflickr.com/9/8228/28884278881_9bc3d02423.jpg) (https://flic.kr/p/L1ptNi)IMG_20160813_203945 (https://flic.kr/p/L1ptNi) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Then I was trying to work out how much chain I needed (I got 3, and I need to use about 2.5, but it's how many links the .5 is that needs thinking), and I realised I had a problem. Because I'm using a jackshaft I need to add a tensioner for the return chain section, and I figured I would use a rear mech I have lying around. Because of how it works, I need to add a mount about an inch away from the beam - I figured adding some extra box section to the side would make it straightforward. But if I do that, then the box is in the way of the top (drive) section of the chain.
The way that I was thinking of mounting the rear mech:
(https://c8.staticflickr.com/9/8893/28344259663_7e4c4c9f6e.jpg) (https://flic.kr/p/KbFJU8)IMG_20160813_204859 (https://flic.kr/p/KbFJU8) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
The problem with the drive section of the chain:
(https://c5.staticflickr.com/9/8493/28928532156_fefd762c01.jpg) (https://flic.kr/p/L5jhKN)IMG_20160813_205205 (https://flic.kr/p/L5jhKN) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I could make the box bigger (or offset it somehow) and run the drive part of the chain through the box. I'm not sure if  that would be a good solution though, time for some thinking!
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 14 August, 2016, 05:56:06 pm
I have a cunning plan.  :) Instead of welding a piece of 40mm box alongside the existing main beam, I can weld a 20mm box across the bottom of the main boom, and put a piece of plate on the end (with a captive nut welded to it). That will give me enough clearance for the drive part of chain, while still giving me a reasonable point to mount the derailleur on. :)
Clearance:
(https://c6.staticflickr.com/9/8707/28903848741_8b27391ae7.jpg) (https://flic.kr/p/L38MeF)IMG_20160814_165325 (https://flic.kr/p/L38MeF) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Mounting point:
(https://c8.staticflickr.com/9/8573/28980084655_552d940177.jpg) (https://flic.kr/p/L9SvvZ)IMG_20160814_165318 (https://flic.kr/p/L9SvvZ) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
I'll have to wait to cut, drill, and weld the end piece though - no garage time today.
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 20 August, 2016, 05:10:28 pm
It rolls! And it stops! And the pedals (sort of) allow you to make it go forwards!   
I welded a nut into some 20x20mm tube, and then welded that to the underside of the main boom:
(https://c8.staticflickr.com/9/8129/29029533391_12f0e978dd.jpg) (https://flic.kr/p/LeeWUp)IMG_20160820_110920 (https://flic.kr/p/LeeWUp) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Then I attached the derailleur to it, sorted out the chain length and turned it up the right way:
(https://c4.staticflickr.com/9/8463/28488074443_aeeb173143.jpg) (https://flic.kr/p/KpoQ2i)IMG_20160820_120004 (https://flic.kr/p/KpoQ2i) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Finally, I put handlebars on and the brake levers onto the bars, and tried to ride it! It worked! Unfortunately it was in the biggest gear it has, which was rather hard to pedal, and the derailleur I'm using for tensioning is kinda twisted so it doesn't do what i is suposed to and keep everything in line. I was able to ride it down the street, but coming back up what is only a slight include proved too much! Anyway, here it is after the maiden voyage!
(https://c5.staticflickr.com/9/8208/28819999260_fffab603bc.jpg) (https://flic.kr/p/KUJ2GY)IMG_20160820_115958 (https://flic.kr/p/KUJ2GY) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I then went to a local bike shop and got some gear cables and outer - I've now sorted out the rear derailleur using a spare thumbshifter, and used another one for a parking brake using the V that was on the back wheel. That seems to work pretty well, but it was hard to take pictures of these bits! It started to rain halfway through these fixes, so I couldn't try another ride on it afterwards. Before I do any more I need to bolt some hooks to the garage wall so that I can hang some of my bikes up - without doing that I will have to carry it in and out of the garage, and it's a heavy old beast! So DIY to do first, and then fine-tuning of the trike! Not sure if I'll get any spare time this weekend, but I've got Monday Tuesday and Wednesday afternoons, so hopefully I can make some progress this week and get it working properly before the end of August (I'm away next weekend so can't work on it or ride it then)!
Cheers
Duncan
PS - yes the brake cables need significant shortening (and the left hand one has much more travel than the right one, which needs to be sorted so I don't end up with too much brake steer), but it's still in dry assembly/proof of concept stage at the moment. There are loads of other bits I need to do before it's finished including (but not limited to): sort the seat out, fix the derailleur tensioner, improve/shorten the handlebars, add grips, shorten the front wheel axles on the outside, tweak the brakes, install a front derailleur (and shifter), shorten the main boom (I reckon it's long enough to fit a 7 foot person with some space to spare)band add chain tube(s) where needed. There is also the possibility of converting to under-seat steering if I don't like the tiller style, and obviously the original plan was to make it foldable. Damn, for a second then I thought I was almost finished!!!  :-X
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 24 August, 2016, 09:50:53 pm
There's good news and bad news!
The good news is that I've sorted out the issues I was having with the middle derailleur (not helped by the fact that if I have the back chain on the big ring and the front chain on the middle ring, then they clash with each other), and got the rear derailleur indexed properly. I then got to ride the trike up and down and up and down the road.  My neighbour also had a go!  :thumbsup:
Here's a still (note the slope and the handbrake holding it):
(https://c6.staticflickr.com/9/8364/29129825181_b52d3a4f95.jpg) (https://flic.kr/p/Lo6Yac)IMG_20160823_162403 (https://flic.kr/p/Lo6Yac) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

There's even a video (horribly shaky, due to being taken by my 7 yo) but I can't work out how to upload it to flickr - I think it's just too big!

The bad news is that while I was riding it, I realised that the crank alignment was horrible (this picture should show that the chain is parallel to the main boom, except for where it goes along the chainset, where the front pints outwards):
(https://c1.staticflickr.com/9/8036/28895116440_e9e49045d9.jpg) (https://flic.kr/p/L2n2qL)IMG_20160823_162941 (https://flic.kr/p/L2n2qL) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
(https://c6.staticflickr.com/9/8373/29129814581_558a30f4d3.jpg) (https://flic.kr/p/Lo6V1r)IMG_20160823_162923 (https://flic.kr/p/Lo6V1r) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
On more serious examination, I discovered a crack in the weld holding the bottom bracket to the left hand plate (as seen from sitting in the seat). 
(https://c8.staticflickr.com/9/8319/29129834991_7989597d9b.jpg) (https://flic.kr/p/Lo725k)2016-08-24_09-03-47 (https://flic.kr/p/Lo725k) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Obviously this will need to come off and get re-welded (and for that I'll need to remove the cranks and the BB). I'm not sure if I need to remove it and then completely re-weld it, or can I get away with straightening everything up, cleaning up the old welded joint where it failed and then welding it again, or need to disassemble and go back to bare metal and 2 separate pieces. I remember (you might even be able to find it on this thread) that I forgot to clean the BB shell properly so the welds were ugly - I thought they were strong enough, but I guess they weren't and that's why this has happened.
I also need to sort out the tip on my MIG - I think it's a bit old and warn, which means that sometimes the wire just pushes the torch away from the thing you're trying to weld! It's also a bit splattery. Not going to help with making strong welds...
Anyway, at least I have proof that the concept works. The only bit that concerns me is how low the tensioner for the front chain run goes - I'm bound to catch it on a speedbump at some point. It's necessary if I want to run gears at the front though and there's nowhere else to put it (unless I guess I flip it completely and run it where my left ankle would go?). Does anyone have bright ideas about how to make this less vulnerable?
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: TheLurker on 25 August, 2016, 06:40:58 pm
*cough* zip tie *cough*  :D

S'looking good thobbut.
Title: Re: Recumbent trike (hopefully folding)
Post by: iddu on 25 August, 2016, 10:33:09 pm
>Does anyone have bright ideas about how to make this less vulnerable

Ditch the mech.

Two flat bars, arranged in a V.  Point to RHS (facing seat rear).  Top 'arm' fixed parallel to main tube at wanted drop.  Jockey wheel/hinge at point, Jockey wheel on lower 'arm' tip.  Spring compressing open end.  Should gain at least cage length additional height...you might have to guide return above steering control rod as well, depending on height wanted.

Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 25 August, 2016, 10:51:20 pm
>Does anyone have bright ideas about how to make this less vulnerable

Ditch the mech.

Two flat bars, arranged in a V.  Point to RHS (facing seat rear).  Top 'arm' fixed parallel to main tube at wanted drop.  Jockey wheel/hinge at point, Jockey wheel on lower 'arm' tip.  Spring compressing open end.  Should gain at least cage length additional height...you might have to guide return above steering control rod as well, depending on height wanted.
That sounds interesting. I'm having trouble visualising - is it essentially the sprung bit of the derailleur? It needs to be able to take enough chain to make the 52, 42 and 30 tooth chainrings usable. At least until I've sorted out the electric propulsion part and I no longer need the smaller chainrings (might take a while, given that I've been working on this for 20 months so far)! :)
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: iddu on 25 August, 2016, 11:43:04 pm
A DIY verison of clicky (https://www.google.co.uk/search?q=recumbent+chain+management&safe=off&biw=1787&bih=900&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjR95uN0d3OAhVLB8AKHdECBlYQ_AUIBigB&dpr=0.9#imgrc=zOqujHn8BsgcUM%3A)
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 26 August, 2016, 09:05:51 am
Ah. That picture explains a lot.  I always wondered how trikes with an adjustable boom dealt with the excess chain - now I know. :)
I guess the ideal scenario would be to have that setup where the top wheel is fixed and the bottom one is sprung such that it moves directly back away from the top wheel but parallel to the ground. I'm not sure if I can rig that with a spring and a slot - I might be better off just using a sprung derailleur arm (or regular singlespeed chain tensioner) with a pivot point significantly forward of (and higher than) the top wheel.
Thanks iddu - I'll definitely try that solution once the trike is back up and functional.  :thumbsup:
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: PhilO on 26 August, 2016, 10:04:30 am
Could the mecb be mounted aa lot further fwd, so that it's nearly between the front wheels? Witb only slack from shifting chainrings to worry about, you coul also use a much shorter cage mech.

Or how about mounting the mech back-to-front so that if it is clonked is just deflects, similar to a Pinion chain tensioner.
Title: Re: Recumbent trike (hopefully folding)
Post by: iddu on 26 August, 2016, 10:06:48 am
>I guess the ideal scenario...

Actually yes, that would be better;  Get some appropriate sized open channel (so jockey bolts get support both sides), offset the jockeys slightly in horizontal plane, slot one ends mounting, and have two (external) springs putting slotted jockey under tension.

Might need to slice out additional entry (or exit) space, depending on how you orient the channel/level of offset/resultant wrapped chainline.

That would really flatten line / raise chain.
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 26 August, 2016, 01:05:21 pm
The channel idea is a really good one - should allow consistent chain tensioning, taking up a minimal amount of vertical space, and hopefully be pretty straightforward to assemble.  It doesn't need to slide very often (only when I change chainrings), so maybe I can get away with alloy as well. Now I need to find some to experiment with. :)

Progress on the physical (as well as the conceptual) side as well. I attacked the badly welded BB clamp with a BFH and a crowbar and pulled it apart! That gave me this piece:
(https://c5.staticflickr.com/9/8276/29133683412_62845e9988.jpg) (https://flic.kr/p/LorK5q)IMG_20160826_114842 (https://flic.kr/p/LorK5q) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Better pic:
(https://c5.staticflickr.com/9/8094/29207929516_c8499d69af.jpg) (https://flic.kr/p/Lv1gRE)IMG_20160826_114849 (https://flic.kr/p/Lv1gRE) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
and this piece:
(https://c8.staticflickr.com/9/8136/29241631135_13ea82e538.jpg) (https://flic.kr/p/LxZ1b4)IMG_20160826_114834 (https://flic.kr/p/LxZ1b4) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Clearly there was very little penetration into the BB shell.
So I cleaned both sides up with a flap disk until they were shiny, replaced the conductive tip on my welder, bolted them to a spare bit of box section (with an extra 1mm sheet in one side for spacing) using the bolts that should hold it to the main boom and some extra clamps, turned the selder up a notch so it was running hot, and then tried again. The result:
(https://c1.staticflickr.com/9/8282/29133689672_902b528174.jpg) (https://flic.kr/p/LorLWm)IMG_20160826_123423 (https://flic.kr/p/LorLWm) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
(https://c7.staticflickr.com/8/7648/29207928166_008e9a0a42.jpg) (https://flic.kr/p/Lv1gso)IMG_20160826_123433 (https://flic.kr/p/Lv1gso) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
I went over the welds on the other side because I felt I ground too much off last time, meaning it looks like this now:
(https://c4.staticflickr.com/8/7530/29241624235_4751c7c370.jpg) (https://flic.kr/p/LxYY86)IMG_20160826_123413 (https://flic.kr/p/LxYY86) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

The extra heat meant that the BB was glowing red all the way through to the inside of the shell - the threads seem to have survived OK (I'll chase them with the tool to be certain), so the only downside appears to have been that I kept setting fire to the grease in them!
Once the thread is chased properly then I can re-install the BB and get going again.

Cheers
Duncan

PS the (super shaky) video appears to have uploaded too :) :
(https://c5.staticflickr.com/9/8417/29100469252_36e976357d.jpg) (https://flic.kr/p/LkvvEu)VID_20160823_162700 (https://flic.kr/p/LkvvEu) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 26 August, 2016, 01:32:08 pm
New idea for how to manage the sliding bit (I would fix the top pulley wheel independently):
Attach these to the inside of some suitably sized box/channel section steel, attach a pulley wheel to one end, and the spring on the other end.  Smooth rolling and (relatively) self contained.
http://www.ebay.co.uk/itm/17mm-280mm-Drawer-Runners-Grooved-Ball-Bearing-Metal-Draw-Slides-/390932002649?var=&hash=item5b055cf759:m:m0ZUjbq0MIc1uRCtTUVw3Eg
Does that make sense?
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: iddu on 26 August, 2016, 02:08:41 pm
Outstanding bodge piece of design ;D
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 12 September, 2016, 09:45:34 pm
I spaced the inner ring inward with a couple of washers per bolt, which means I can use the middle ring for the back chain.  That reduced my gearing considerably (I think the theoretical top was 136", and now it's 103"!). And I worked out what was causing the front wheel to lock up - it wasn't the brakes binding, but one of the bolts holding the rotor on had come loose! The head was totally mangled, but I managed to remove it, so I got to ride it up and down the street a bit more - the gearing reduction makes it a lot easier!
Unfortunately, the derailleur is still problematic, and it's not going to be as easy as I'd hoped to fit a sliding tensioner. I think this picture illustrates the current setup best (though the front chain is running on the inner ring now, so my issue is slightly worse!):
(https://c3.staticflickr.com/9/8149/28819998250_fd3d42818f.jpg) (https://flic.kr/p/KUJ2py)IMG_20160820_120008 (https://flic.kr/p/KUJ2py) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
To get a nice sliding mechanism in place, what I'd want to do is fit the fixed front jockey wheel around about where the base of the seat is, and then that would give me a foot or 2 of space behind and under it to have the sliding pulley and the mechanism needed. Unfortunately, that's exactly where the tensioned part of the chain runs. I could reduce the deflection in the tensioned part of the chain by using a smaller diameter pulley wheel, or by putting the existing one on the top of the boom instead of the bottom (I'd rather not do that as it's pretty solidly welded on). But while that would make life a bit simpler, it wouldn't solve the problem. It might be part of the solution, together with some extra sheet on the side to allow me to mount everything below the tensioned chainline. I don't think it's properly ridable until I create a solution though. :(
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 13 September, 2016, 08:11:03 pm
Maybe I can just get away with a fixed jockey wheel together with this:
http://www.planetx.co.uk/i/q/FSOOSSD/on-one-doofer-singlespeed-chain-tensioner
Would make life easier. Cheap too...
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 16 September, 2016, 10:06:16 pm
Well that was an unmitigated disaster.  >:( :'(
I got my new tensioner today. It's pretty sturdy, but it's surprisingly (to me at least) small! Here's a (rubbish, sorry) picture:
(https://c2.staticflickr.com/9/8042/29724865105_978a578cc7.jpg) (https://flic.kr/p/MhFGNe)2016-09-16_09-24-45 (https://flic.kr/p/MhFGNe) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
It's about as long as the arm on my junk derailleur. So I tried to work out how to attach it in the right place, shortened the chain, and generally realised that I can't use it on the mounting point very easily, and I need another one (or a fixed jockey wheel) to make the tensioning work.

Then I tried to put a second roller on my existing mounting side by side so I could change the route of the return part of the chain. The central part of it wouldn't slot on properly, so I hit it a few times with a hammer to push it on. Then I realised that the bolt had moved in the tube, I hit the bolt, at which point my welds failed. :( This was another weld I made when the tip on my welder was not working properly - I will have to check back and make sure there aren't any others (I think I've broken the only 2!).
(https://c4.staticflickr.com/9/8334/29100494643_b09fecb016.jpg) (https://flic.kr/p/LkvDdg)2016-09-16_09-24-56 (https://flic.kr/p/LkvDdg) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Right now I feel like recycling it!  >:(

So, I have 3 options (some with sub-options):
1. Carry on with my current jackshaft design and work out how to fix the chain tension issue.
2. Change over to a different jackshaft design that uses a freewheel/cassette and so has a mounting point for a derailler for this chain - this means abandoning the theoretical ability to attach a motor to the left hand side of the jackshaft.
3. Give up on jackshafts. Weld the roller bolt back onto the frame, ditch the jackshafts and just run the chain front to back.
3a. Leave the rear wheel alone - this will give me really low gears (when I eventually sort out the front mech to shift chainrings) - something like 21 inches to 71 inches with the current rear wheel.
3b Get a new screw on freewheel (11-28 would give 21" to 90"). Also needs a new shifter as my current one only has 6 gears in index mode.
3c Build a new rear wheel on a decent hub meaning I can get whatever gear ratios I want. Means I need a new hub, spokes, rim (can probably re-use one I have) cassette, shifter and maybe derailleur.

I've got stuff I need to do this weekend, so I probably won't have much time to work on it. Will consider my options. I'm kinda fed up of it now, I want to ride it (and start on my next build - a Spirit mid-racer recumbent).
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 25 September, 2016, 06:49:40 pm
I decided to use just the one chain, and run it  from the cranks, under the pulley, over the jackshaft, round the wheel, though the rear mech and then back to the front (maybe through a chain tube).  So I did this:

Progress today.
I cleaned up the bolt for the pivot and welded it back on.  Left the welder at setting 6 - lots of heat. Much better penetration - this is after I ground off a few bits of splatter:
(https://c2.staticflickr.com/9/8738/29838310361_228ba9c672.jpg) (https://flic.kr/p/MsH97V)IMG_20160925_155455 (https://flic.kr/p/MsH97V) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

(https://c7.staticflickr.com/9/8158/29807405342_b160427fda.jpg) (https://flic.kr/p/MpYK8L)IMG_20160925_155507 (https://flic.kr/p/MpYK8L) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

While I waited for it all to cool down I stripped the old chain off and extended the new one so it goes all the way from front to back.  Then, when the bolt was sufficiently cool, I put the pulley back on, bolted it up and went for a ride up and down the road. :) It basically just works now. :) This is the current chainline situation:
(https://c4.staticflickr.com/9/8439/29921628595_ff8fa4cb54.jpg) (https://flic.kr/p/MA5aJc)IMG_20160925_162428 (https://flic.kr/p/MA5aJc) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I need to sort out the bottom bracket, because it's slightly twisted, and once that's done I can look into sorting out a front mech (I can shift gears by hand until then) and some tubing to deal with the return chain. Other than that, it's the riding it and tidying up.  Speaking of which:
1. I got a mirror from eBay and it's not very much use - it's quite small and a long way away, so it's not exactly helpful - what do people on here use (I assume you use mirrors - it doesn't feel very safe without them) and how do you mount them?
2. How does one mount the flag on the back?  Again - eBay flag, sees quite well made, but isn't obvious how you are supposed to put it on:
(https://c5.staticflickr.com/9/8560/29627250900_b41f27a0d0.jpg) (https://flic.kr/p/M94puG)IMG_20160925_162649 (https://flic.kr/p/M94puG) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
3. Where does one cut the axle off? This is what it looks like now, and it catches on stuff when I put it in and out of the garage:
(https://c3.staticflickr.com/9/8082/29886486826_e58694b7f8.jpg) (https://flic.kr/p/MwY4iC)IMG_20160925_165811 (https://flic.kr/p/MwY4iC) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr


Progress on prepping for the next project (I want to build a Spirit recumbent bike - looks a bit like an HP Velotechnic) - I chopped the old crank off the donor rear triangle - had to cut 2 separate slots in it as even after I had chopped a quarter of the crank off it still wouldn't budge!:
(https://c3.staticflickr.com/9/8389/29294227834_014932269b.jpg) (https://flic.kr/p/LCCzkG)IMG_20160925_164345 (https://flic.kr/p/LCCzkG) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

I was then able to get the BB out, and then I chopped the back triangle off the main frame:
(https://c5.staticflickr.com/9/8232/29807400372_70803efbfb.jpg) (https://flic.kr/p/MpYHE5)IMG_20160925_165959 (https://flic.kr/p/MpYHE5) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
It's kinda hard to undo the bolts though - I might end up having to drill it out. :(
I'll create a new thread for that at some point when I do more than chop old bikes up! :)

Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 02 October, 2016, 06:14:56 pm
One step forwards, one back....
I tack welded along the edges of the clamping plates so that when they were done up the chainset is now parallel with the main boom. :)
I then discovered that the front mech isn't going to work, because the seat tube of the bike I chopped up is curved - the lower portion is at the correct angle, but the top portion leans back too much. I guess I'm going to have to chop the tube halfway down and fit a straight one over the top so it goes high enough at the correct angle...
Planning on chopping the axle stubs this evening and trying to ride it up and down the street again. I also need to adjust the mirror location, because it's a bit far way, meaning it's hard to get a picture of what's actually behind you...
While it would be nice to get the front mech working, it's not actually vital to riding it - I can always change gear using my hand! So long as today's modification works, it feels a little like it's basically usable, and everything left now is fine tuning and adding nice to have features like mudguards/lights/mirrors/chaintube/proper seat covering/folding etc. That is a lot of things to add before it's "finished", but they shouldn't stop me geting on and trying it out. Hell, maybe I'll want to add under seat steering!
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: mzjo on 28 November, 2016, 01:02:24 pm
 Too late for this build but re the bb shell, in Holland you can get (off the peg) bb fittings designed to slide on and clamp on 40mm box section (alignment square to your tube guaranteed). They say it's for 40mm alu box but I don't see why it shouldn't work for steel as well. I'll sort out the link if anyone is interested. Not the cheapest of solutions but might be worth having strong and hasslefree bb fitting.
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 28 November, 2016, 08:09:15 pm
The link would be nice - I'm thinking of building a 2 wheel recumbent when this one is finally done! ;)
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 18 May, 2017, 09:05:28 am
Too late for this build but re the bb shell, in Holland you can get (off the peg) bb fittings designed to slide on and clamp on 40mm box section (alignment square to your tube guaranteed). They say it's for 40mm alu box but I don't see why it shouldn't work for steel as well. I'll sort out the link if anyone is interested. Not the cheapest of solutions but might be worth having strong and hasslefree bb fitting.
Hi mzjo - do you have this link?

I made some progress on this project a couple of weeks ago - cut the tube for the front mech - made a moon shaped spacer out of 1mm steel, welded it into the gap and fitted the mech.  I also dismantled an old rear mech, so now I have a little bracket to weld onto said tube to act as a cable stop. Waiting on another thumb shifter (will have to pop down to the Broken Spoke this weekend to get one) - I think I have sufficient outer and inner cable to do the rest of it now.  The same weekend friends came around to borrow the welder to make a tall bike - they all had to have a go on the trike! :)

Once the front mech is sorted, it will be time to ride the thing around the place a bit and sort out the headsets properly. :)
Title: Re: Recumbent trike (hopefully folding)
Post by: Von Broad on 18 May, 2017, 09:54:24 pm
Congratulations on the build. That's a fine effort for a first offering.
Mild steel can obviously get very heavy but it's very forgiving and really good to MIG. It used to amaze me how much weight is added after welding [might have something to do with how much stuff I was putting down there]. And of course all sorts of scrap bikes are lying about the place ready to have their bits chopped off to be adapted elsewhere!

it will be time to ride the thing around the place a bit and sort out the headsets properly. :)

It's satisfying to build a bike, and equally satisfying to put some miles on it to show that it's a worthy machine and actually rides well. Putting through it's paces also tends to bring forth all kinds of weaknesses and issues that weren't apparent as it's sitting in the garage. But that's all part of the fun. Then more ideas comes and you go onto the next build. And then the next.

Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 19 May, 2017, 02:20:30 pm
Congratulations on the build. That's a fine effort for a first offering.
Mild steel can obviously get very heavy but it's very forgiving and really good to MIG. It used to amaze me how much weight is added after welding [might have something to do with how much stuff I was putting down there]. And of course all sorts of scrap bikes are lying about the place ready to have their bits chopped off to be adapted elsewhere!
Thanks. :)
I'm already wondering about whether I can teach myself to TIG using my current machine (I have a scratch start inverter box with a few tiny gas bottles), or whether I should go out and buy something that will require less skill to start! That would mean I could weld thinner more bike suitable tubes!
It's satisfying to build a bike, and equally satisfying to put some miles on it to show that it's a worthy machine and actually rides well. Putting through it's paces also tends to bring forth all kinds of weaknesses and issues that weren't apparent as it's sitting in the garage. But that's all part of the fun. Then more ideas comes and you go onto the next build. And then the next.
I've not yet got to the satisfying riding bit, but I already have some more steel tube, a chopped up MTB, and a kids BMX sitting in my garage waiting to turn into a SWB 2 wheeled recumbent. A head-tube and a back wheel and I'll have enough bits to get started! Must finish the trike first! :)
Title: Re: Recumbent trike (hopefully folding)
Post by: Torslanda on 20 May, 2017, 12:15:35 am
It's more than a decade since I built a recumbent. Maybe it's about time to build another...
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 05 August, 2017, 04:12:29 pm
Front mech sorted. :)
(https://farm5.staticflickr.com/4336/36218480962_a7b13bb031_z.jpg) (https://flic.kr/p/Xbvbyj)IMG_20170805_150259 (https://flic.kr/p/Xbvbyj) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Now looks like this:
(https://farm5.staticflickr.com/4418/36386380145_d5995f02b7_z.jpg) (https://flic.kr/p/XrkH8P)IMG_20170805_155224 (https://flic.kr/p/XrkH8P) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
(https://farm5.staticflickr.com/4377/36249702061_64e4db111c_z.jpg) (https://flic.kr/p/Xegcv8)IMG_20170805_155231 (https://flic.kr/p/Xegcv8) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Time for a ride. Only a short one though! https://www.strava.com/activities/1118507312/overview
I feel like I've been doing a 20 minute crunch! Is that normal? I assume that I need to sort out a headrest (and maybe a backrest that's a bit higher)? Thinking about it a bit more - maybe it's because I'm stretching a little to get to the handlebars?

On the plus side, the gears all work, and they are low enough to mean that I won't need to get off and push much! The handbrake works well, and the front brakes are amazing (and contribute to it's agility because you can do torque vectoring :) ).

On the negative, the gears don't go all that high (the problem with 20" wheels and no step-up gearing). I need to sort out the headsets, because they are loose, and it has wicked bump steer! I also need to make the backrest more effective, or add a headrest, because it felt like I was doing crunches for 15 minutes! And I should chop the handlebars in front of the stem so that they stop whacking me in the shins! Plus, if I actually want to use it, when I've sorted that lot out I need to make some mudguards and work out how to mount lights and a flag. Flag is the first job so I can ride it into town to get the headsets sorted at my favorite bike shop. Until it folds I don't think I can get it into the car!

Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 06 August, 2017, 07:43:47 pm
I fitted an eBay flag today by drilling new holes in the mounting bracket like this:
(https://farm5.staticflickr.com/4376/36363288316_6c206245ac_z.jpg) (https://flic.kr/p/XpimJQ)IMG_20170806_175109 (https://flic.kr/p/XpimJQ) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Now it looks like this:
(https://farm5.staticflickr.com/4354/36271377661_4e0d49b025_z.jpg) (https://flic.kr/p/XgbhUn)IMG_20170806_175042 (https://flic.kr/p/XgbhUn) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

and I chopped a small amount off the front part of the bars - they now look like this:
(https://farm5.staticflickr.com/4424/36271374581_5ec3a75025_z.jpg) (https://flic.kr/p/XgbgZg)IMG_20170806_175102 (https://flic.kr/p/XgbgZg) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

They aren't completely chopped, but they make a massive difference to how easy it is to turn without bashing my legs. I don't think the handlebar length is the problem for my back. I think the lack of an upper back rest is the issue - the backrest is currently stopping just below my shoulder blades. I need to build the top bit of the back rest as per the design. The instructions aren't clear on exactly how long it should be (or exactly where on my body the rest should stop) - where do they reach on other similar trikes that are set up correctly?

Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: loadsabikes on 07 August, 2017, 03:29:33 pm

I'm already wondering about whether I can teach myself to TIG using my current machine (I have a scratch start inverter box with a few tiny gas bottles), or whether I should go out and buy something that will require less skill to start! That would mean I could weld thinner more bike suitable tubes!

I wouldn't bother. Tig is probably the hardest welding discipline to master and inferior equipment just makes it tougher.
You would probably be better trying your hand at gas brazing for steel tubing.
Title: Re: Recumbent trike (hopefully folding)
Post by: Kim on 07 August, 2017, 09:05:14 pm
They aren't completely chopped, but they make a massive difference to how easy it is to turn without bashing my legs. I don't think the handlebar length is the problem for my back. I think the lack of an upper back rest is the issue - the backrest is currently stopping just below my shoulder blades. I need to build the top bit of the back rest as per the design. The instructions aren't clear on exactly how long it should be (or exactly where on my body the rest should stop) - where do they reach on other similar trikes that are set up correctly?

Seat back comes to just above my shoulders on my bikes (hardshell seats) and very slightly lower on barakta's trike (mesh seat).  You certainly need your shoulder blades supported, as that's where you'll tend to push against the seat back while pedalling hard (recumbent equivalent of pulling on the bars).

You might still want a neck/head support above that, depending on how reclined the seat is and how long you're likely to ride it for in one go.
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 07 August, 2017, 09:35:01 pm
Quote
I'm already wondering about whether I can teach myself to TIG using my current machine (I have a scratch start inverter box with a few tiny gas bottles), or whether I should go out and buy something that will require less skill to start! That would mean I could weld thinner more bike suitable tubes!
I wouldn't bother. Tig is probably the hardest welding discipline to master and inferior equipment just makes it tougher.
You would probably be better trying your hand at gas brazing for steel tubing.
I had a go at TIG a few years ago - I was able to join 1mm flat sheet without filler wire OK. I struggled with scratch start though - I could imagine spending a lot of time sharpening tungstens and a lot of wasted gas if I use my little machine. I've not got any brazing gear, and given the garage is directly below the living room, I doubt I could persuade my wife that having an oxy acetylene setup down there is a good idea.

They aren't completely chopped, but they make a massive difference to how easy it is to turn without bashing my legs. I don't think the handlebar length is the problem for my back. I think the lack of an upper back rest is the issue - the backrest is currently stopping just below my shoulder blades. I need to build the top bit of the back rest as per the design. The instructions aren't clear on exactly how long it should be (or exactly where on my body the rest should stop) - where do they reach on other similar trikes that are set up correctly?

Seat back comes to just above my shoulders on my bikes (hardshell seats) and very slightly lower on barakta's trike (mesh seat).  You certainly need your shoulder blades supported, as that's where you'll tend to push against the seat back while pedalling hard (recumbent equivalent of pulling on the bars).

You might still want a neck/head support above that, depending on how reclined the seat is and how long you're likely to ride it for in one go.
OK. Sounds like I need to build a seat extender then. Thanks for that - I'll see what I can come up with. :)
Cheers
Duncan
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 19 September, 2017, 04:12:23 pm
I figured out how to build a seat extender that allows an adjustable angle by using an old folding bike stem. So I cut the centre off an old set of handlebars and welded them onto the seat post. Sadly my welder was out of gas and the welds sucked, so I need to get some more gas before I can try again...
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 24 July, 2018, 03:52:08 pm
Almost a year since I last updated this.  :-[
I need to get on with making it usable - my daughter is pestering me to ride it work before she goes back to school (though the chances of her being able to ride it are almost nil (it's set up for me at 6ft and she's 4ft - pulling the bottom bracket back far enough for her to reach would mean the cranks bashing the crossbeam)).

I did look at my little scratch start TIG, but the dials on the front are damaged/missing - I should probably just get rid (and, if funds allow, get something more modern).
Title: Re: Recumbent trike (hopefully folding)
Post by: Kim on 24 July, 2018, 06:57:27 pm
I need to get on with making it usable - my daughter is pestering me to ride it work before she goes back to school (though the chances of her being able to ride it are almost nil (it's set up for me at 6ft and she's 4ft - pulling the bottom bracket back far enough for her to reach would mean the cranks bashing the crossbeam)).

Don't underestimate the ability of a sufficiently determined child to ride a recumbent that doesn't even slightly fit :)
There's a photo somewhere of EldestCub successfully riding my Streetmachine with his shoulders leaning on the bum-end of the seat and his back arched over the steerer...
Title: Re: Recumbent trike (hopefully folding)
Post by: Torslanda on 25 July, 2018, 09:25:10 pm
Many, many moons ago Redshift and I were standing on Morecambe Prom eyeing up various offerings at CycleFest. I suggested she had a go on a Trice and got a vaguely negative response which included 'It's probably set up for someone much taller!' and so on.

Five minutes or so later a chiddler of about 7 trundled past on one. Backside wasn't even touching the seat . . .
Title: Re: Recumbent trike (hopefully folding)
Post by: Kim on 25 July, 2018, 09:33:33 pm
Five minutes or so later a chiddler of about 7 trundled past on one. Backside wasn't even touching the seat . . .

I have grainy video of ?SmallestCub photobombing a BBC Midlands Today interview about all the cycle infrastructure they were about to build[1] by doing just that.


[1] Spoiler:  They didn't.
Title: Re: Recumbent trike (hopefully folding)
Post by: Wobbly John on 26 July, 2018, 09:42:48 am
Many, many moons ago Redshift and I were standing on Morecambe Prom eyeing up various offerings at CycleFest.

The last of those glorious events was in 2004!  :o

Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 29 December, 2019, 07:15:32 pm
I molished a random backrest for this and rode it on the rollers today.
The old backrest was shaped ply with special captive nuts and sensible bolts, but I couldn't find it in the garage! New one was a part of a shelf, held in place with wood screws. Worked better as it had more height and so supported my upper back better! Now all I need to do is cut some random steel, bend it to a suitable headrest position and work out how to stiffen it sufficiently to stay there. :)

Side note - I saw on a BHPC picture the other day a steering damper on some old trike. Anyone know what that was nicked from? It might make it easier to ride this thing (outdoors) without every tiny bump bouncing the steering around the place.
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 19 January, 2020, 10:38:57 pm
I resolved the neck rest with more wood, and I rode it about 5 times on the rollers. I've gone back to the upright for now as I can't get enough resistance on the rollers (I was in the biggest gear I have at 90rpm doing around 200W), and also because I don't have my 'bent legs and I don't want to lose fitness getting them (this is, after all, just an experiment - I'm not racing the thing).

I can answer my own question - there are loads of steering dampers for go carts and also for motorbikes on eBay.  At some point I'll actually try riding it outside again, and maybe at that point I'll decide it needs one, but I'm not going to bother until then...
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 08 April, 2020, 09:55:44 am
It's back on the rollers (so that my head height and that of my daughter are roughly equal), still with the issue that I can't get enough speed on it to get proper power.  I have noticed that I seem to gravitate towards 75rpm rather than 88 or so on the upright. The cranks are 175mm long secondhand carbon ones that I found lying around in my garage, but they have the benefit of 30-40-50 rings and a new BB, so they are going to be staying for a while I suspect.  I'm also wondering if I can get my jackshaft to work again. Chain tension was the problem last time, but I reckon I can just run a regular short cage derailleur on the front loop of chain if I set it up properly. Experiments beckon on that front, because I have all the parts. :)
I also want to get a new seat, because the wooden one sucks. It will almost certainly end up coming from overseas, and cost more than any other part on the trike (even a fibreglass one), so I've not got much further than looking at them online. It would be a lot more convenient if I could actually try one!

Getting my daughter onto the turbo necessitated a little bodgery:
(https://live.staticflickr.com/65535/49731596811_996ef35f45_k.jpg) (https://flic.kr/p/2iLBr7k)2020-04-03_06-25-30 (https://flic.kr/p/2iLBr7k) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Unfortunately, having moved the pivot so that it can contact the wheel, the bolt to hold it at the right tension is too short. For the moment, it's got a bit of wood propping it into the right place (this is definitely "bodge it") - at some point I am going to have to try to find a suitable long bolt. It works though. :)

If I can sort out the trike such that I'm happy riding it consistently, I might apply this bodge to my wheel on smart trainer and see what she thinks of Zwift! ;)
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 18 April, 2020, 04:07:08 pm
I think the trike seat is actually bad for me when I'm trying to ride at a reasonable power. Fundamentally, the backrest is a shelf, so it's only about 6 inches wide, and I think that if I push back into the seat then I end up sort of flexing my back and pulling wher emy ribs join my sternum.  Combined with breathing a bit more, that hurts.

So, I have a new seat design.  I downloaded the plans from a user called Atom on the bentrider forum, and made the form, around which a seat can be produced. It ended up being re-inforced in a few places as just having these bits was a bit wobbly, but I don't have a good photo of that!
(https://live.staticflickr.com/65535/49788296563_1242d244b6_z.jpg) (https://flic.kr/p/2iRC2Yg)2020-04-18_03-57-36 (https://flic.kr/p/2iRC2Yg) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Unfortunately, I couldn't find anywhere that would deliver the required 3mm plywood in these strange times, so I thought I'd have a go of making it out of 1.2mm zintec steel (I happen to have some of that lying around, plus some really handy tools for cutting it). And I can always weld it to stuff too. I was even wonder about panel beating those little wings that are supposed to hold you in place, thought I may end up just cutting it a bit and then welding them on. I made it 35mm wide, because I figured I could always trim it down - while welding extras on is fine, adding a few mm down the entire length is beyond my skills!
(https://live.staticflickr.com/65535/49789152382_686e322d36_z.jpg) (https://flic.kr/p/2iRGqnL)2020-04-18_03-57-56 (https://flic.kr/p/2iRGqnL) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

Hopefully when I release my ratchet straps it doesn't just spring back! I'll probably lose a little bit of the shape, but that's not too big a deal - I can always use the ratchet strap to basically turn it into a circle and then straighten out the middle bit again. The only minor annoyance is that I've actually managed to strap it to the Workmate! This is probably good for the rigidity of the structure, but it doesn't help me get it into the garage! So it might just have to be released this evening.

Once I'm happy with the shape I need to work out how I'm going to attach it to the trike. Bracketry is fairly simple to make though, so hopefully that won't be a problem.  Maybe I can even make it adjustable? First things first - get it to a shape I can sit on!
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 18 April, 2020, 05:50:43 pm
As expected, it sprung out a lot. :(
(https://live.staticflickr.com/65535/49788702688_5b3d3420d9_z.jpg) (https://flic.kr/p/2iRE7Gq)2020-04-18_05-48-24 (https://flic.kr/p/2iRE7Gq) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

So I took it off the buck and over-bent it. I'll revisit it tomorrow.
(https://live.staticflickr.com/65535/49788703608_e4cb78103c_z.jpg) (https://flic.kr/p/2iRE7Yh)2020-04-18_05-48-41 (https://flic.kr/p/2iRE7Yh) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 18 April, 2020, 08:29:05 pm
It just sprung back. And it's heavy. But it kinda works when I put it straight on top of the existing seat.

I have a piece the same length about 10cm wide. I could just whack that piece into my mould so it's basically the same shape, and then put them into the mould together to the right shape, before welding them together. Hopefully that would add a bunch of rigidity, in the same way that laminating the plywood does. It would add yet more weight, but it might make it work as a seat.

I saw someone on YouTube cutting 1mm deep lines into his plywood so he could bend it properly. I could do that if I had a cirular saw, but I don't have a suitable tool I don't think. :(
Title: Re: Recumbent trike (hopefully folding)
Post by: DuncanM on 27 May, 2020, 02:03:19 pm
I got some thin plywood when I was ordering other stuff to make a bench. My wife didn't appreciate me leaving a couple of "bits of wood" in the bath to soak, but I think this is a result:
Bending one sheet:
(https://live.staticflickr.com/65535/49941476871_ef93c44f2c_k.jpg) (https://flic.kr/p/2j6a894)IMG_20200524_195626 (https://flic.kr/p/2j6a894) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
Sticking the 2 together (count those clamps)
(https://live.staticflickr.com/65535/49940959933_19187c5282_k.jpg) (https://flic.kr/p/2j67ttk)IMG_20200525_203449 (https://flic.kr/p/2j67ttk) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr
I think there were 4 welding clamps and 9 G clamps of various types and sizes. Plus I added a bunch of staples (and then my staple gun ran out.
Result. :)
(https://live.staticflickr.com/65535/49940960063_d899f09eb8_k.jpg) (https://flic.kr/p/2j67tvz)IMG_20200526_201234 (https://flic.kr/p/2j67tvz) by duncancmartin (https://www.flickr.com/photos/90461577@N00/), on Flickr

There's a few voids around the edges, but it's 16 inches wide (and 4ft long) so it needs to be cut down anyway. I got that size because it meant that 6 pieces fitted onto a 8x4 sheet with nothing left over. I guess if I trimmed 3" from the side I could stick that on the back in the middle and really reinforce it. It's pretty sturdy though, so if I make a sensible bracket to go on the back I could probably attach it to my trike quite neatly. Sadly my hip is irritating me no matter what I do, so I'm not going to be riding it for a while. I might even hand onto the seat and see how it goes on my new 2 wheel recumbent. Watch this space for developments (I'm designing it myself so I need to teach myself fusion 360 before I start chopping steel up, otherwise it will all be wonky!).
Title: Re: Recumbent trike (hopefully folding)
Post by: Von Broad on 07 June, 2020, 09:32:58 pm
Good work. Work done is never wasted as it's all about the learning. The thing that leaps from the page for me [save the fact you've built a seat for yourself] is that you're moving imperceptibly onto making a composite version :) The lightest and stiffest way forward. Way to go.

Once you've got the shape right, as it looks as though you're very close to getting with that plywood seat, then you're well on the way to having a plug/mold to shape with. Working with composites is another learning curve, but it's well possible with the very minimum of equipment. It doesn't have to be carbon fibre either - glassfibre is perfectly adequate.

Getting back to the present though, your plywood seat will be plenty strong enough, but, depending on how you attach it to the frame, some unwanted flexibility might be an issue. But you'll have to see.

Watch this space for developments

We will be :-)
Title: Re: Recumbent trike (hopefully folding)
Post by: Dave_C on 08 June, 2020, 12:14:37 am
Great thread! Many thanks for bringing this back up.

Sent from my HD1913 using Tapatalk

Title: Re: Recumbent trike (hopefully folding)
Post by: mzjo on 17 July, 2020, 10:27:44 pm
If you want to do a composite seat the ply form will work as a mould. The lazy way of doing this is with the ply  in vaseline to make it release. I did a lot of bodywork mods like this on my mother's Marlin kit car and they all worked very well. For a proto you don't bother too much about moulding finish as you can sort that out with sanding and polishing afterwards (even if the purists would say that this is work that should be done before producing the article rather than afterwards but for prototyping that doesn't make sense to me and my way is much quicker.