Author Topic: Tales from the Wobbly Workshop  (Read 75899 times)

Re: Tales from the Wobbly Workshop
« Reply #200 on: June 23, 2014, 01:21:55 pm »
Mike Burrows's Ratatcher LWB recumbent has only a few degrees castor, and I think the original version (with a 'one legged front fork') had less than the one below.



Although I haven't made one it certainly should be possible to construct a rideable bike with no castor angle.

However, rideability is not quite a standard from one person to the next.
If it ain't broke, fix it 'til it is...

Kim

  • Timelord
Re: Tales from the Wobbly Workshop
« Reply #201 on: June 23, 2014, 01:36:57 pm »
Presumably with zero castor, the rider is required to balance the bike - ie. the bike won't be stable on its own.
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Tales from the Wobbly Workshop
« Reply #202 on: June 23, 2014, 09:23:41 pm »
BTW, I was busy last week tweeking and running jobs on the laser cutter for Year 9 classes, and mananged to fit a quick 'lunchtime' job in - Wobbly Towers has been needing a new house number for some time and I thought a granite plaque would look quite posh. We haven't tried granite in the laser cutter before  :demon:



Polished, 8mm thick, granite tile, Laser etched text and 'spot centres' for the holes. 20mm dia hole for the doorbell drilled with diamond 'core' drill, screw holes drilled with pointed carbide glass drills. Edges sanded with wet&dry and polished on polishing wheel.  :smug:

If it ain't broke, fix it 'til it is...

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: Tales from the Wobbly Workshop
« Reply #203 on: June 24, 2014, 11:39:42 am »
IIRC the very first Ratcatcher was built as a test hack.  It had a vertical head tube and an adjustable monoblade, allowing the user to dial in as much or little steering wossname as required.
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

Re: Tales from the Wobbly Workshop
« Reply #204 on: June 25, 2014, 05:10:01 pm »
Caster may contribute to the stability or "feel" of a bicycle but bicycles can be stable without caster and without gyroscopic effect. For details, including videos, see:

http://bicycle.tudelft.nl/stablebicycle/

"Our results show that various design variables, like the front mass location and the steer axis tilt, contribute to stability in complex interacting ways."

"We have found no simple physical explanation equivalent to the mathematical statement that all eigenvalues must have negative real parts"

Re: Tales from the Wobbly Workshop
« Reply #205 on: July 08, 2014, 09:31:04 pm »
Another non-cycling project again, I'm afraid.

My daughter acquired an old table for the garden, but it needed a little restoration. I forgot to take a photo until after I had dis-assembled it.  ::-)



I started by sanding to see how much good wood remained (My big, F Off, Makita belt sander used first before the orbital sander shown here).



The centre section of the top had gone toooo far, so I built a replacement section.



A couple of the screws holding the hinges had 'rounded slots' - solution?...

...Tack weld a nut onto the head and use a spanner.  :demon:



A couple of pinned mortice & tenon joints on the frame had to be taken apart, cleaned, glued and re-pinned (new iroko dowels made) but the rest of the joints were just re-glued in situ - gorrilla glue applied and heated with paint stripper until it liquifies and penetrates the timber & joint (then dampen).

For a finish, I used danish oil (2 coats), a coloured wax to disguise the slight timber mis-match and a final coat of white wax (heated to penetrate the wood).

I'm quite pleased with the result.  :smug:



(a couple of bits of the old top placed on table for comparison)

If it ain't broke, fix it 'til it is...

Re: Tales from the Wobbly Workshop
« Reply #206 on: July 09, 2014, 11:20:25 am »
Not sure if I've said this before, (if I haven't I've certainly thought it), but for me this is about the best thread on this forum. It's amazing what people chuck away which with a little tlc can look SUPERB again. Your other projects do you proud and are fascinating, wobbly.
Bread of heaven, bread of heaven.

Kim

  • Timelord
Re: Tales from the Wobbly Workshop
« Reply #207 on: July 09, 2014, 12:48:51 pm »
It's amazing what people chuck away which with a little tlc, the right skills and access to a large assortment of tools can look SUPERB again.

FTFY


I'm no stranger to making good use of discarded tech, but most of what Wobbly John does is beyond me.
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Tales from the Wobbly Workshop
« Reply #208 on: July 09, 2014, 01:20:39 pm »
+1

I'm doing well to slap some "wood stain" on the garden table when it looks shabby, whatever that stuff is.  Wot John is doing up there appears to be a professional restoration job. :thumbsup:

Vince

  • Can't climb; won't climb
Re: Tales from the Wobbly Workshop
« Reply #209 on: July 09, 2014, 02:03:36 pm »
Two great tips here, welding a nut on to jiggered screw (Not sure I can use this to justify buying a welder thoughbut) and using heat to get glue into a worn joint - I'll be trying that on our dinning chairs when I can access some Gorilla glue.
216km from Marsh Gibbon

Re: Tales from the Wobbly Workshop
« Reply #210 on: July 09, 2014, 10:24:54 pm »
I've just realised that there is an invention of mine, in the background of the last photo.

'Mrs Wobbly' bought a birdtable several years ago, but it always blew over and got damaged when it was windy, so most of the top has been replaced over the years. About 18 months ago, the stand was rotting.

  • The bird table is only really used in winter.
  • We have a cast iron parasol base that is only used in summer

All it needed was the top of the bird table mounting on a post (mahogany) that is rounded at the bottom to fit in the parasol base. It is yet to be blown over by high winds.  :smug:



I could probably make a fortune out of this idea if I had any business sense. ::-)
If it ain't broke, fix it 'til it is...

Re: Tales from the Wobbly Workshop
« Reply #211 on: July 14, 2014, 10:47:14 pm »
It's amazing what people chuck away which with a little tlc can look SUPERB again.

Here's a couple of bits of my garden funiture...



...and, yes - both the table and the bench were skip finds.  ;)

The bench needed a new arm and stretcher, and the table needed a new centre and a bit of glueing (it had probably had a parasol through it in too high a wind) and new bolts for the legs.  :smug:

It annoys me that wood, that has taken years & years to grow, gets thrown away because people can't be bothered to look after the products made from it.  >:(

Last Thursday's skip haul included several bits of mahogany (actually it's sapele).  :demon:
If it ain't broke, fix it 'til it is...

microphonie

  • Tyke 2
Re: Tales from the Wobbly Workshop
« Reply #212 on: July 17, 2014, 03:34:01 pm »
I inherited an alternative to the parasol base when I bought my house: an old plant pot filled with concrete that had had a strategically placed bit of plastic pipe inserted to create a hole to accept the parasol pole. I buried this into the lawn & use it for my rotary drier but it could be used for parasol/bird feeder/swingball etc.
Bingo! That's what I am, a saviour.
A sort of cocky version of Jesus.

clarion

  • Tyke
Re: Tales from the Wobbly Workshop
« Reply #213 on: July 31, 2014, 05:09:18 pm »
Remember the ukulele project?

Well, when the teachers came back, in September, from their summer holidays (while I had been making new benches & shelves for the workshop  >:(), they announced we would be going ahead with the uke project.

This has meant that, in my 'spare time' I had to machine up 60 ukulele kits for the Year 5 students to assemble. It takes about 1/2 hour to do each kit. ::-)

I then found out that the teacher who was given the prototype machined uke kit, couldn't be arsed to assemble it to try it out - so nobody had actually trialled the uke kit I designed.  :facepalm:



Is this an accurate picture?   As seen at the cafe in the Olympic Park.

P7270020 by TJ Clarion, on Flickr
Getting there...

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: Tales from the Wobbly Workshop
« Reply #214 on: August 01, 2014, 10:59:15 am »
Need some of these:

External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

Vince

  • Can't climb; won't climb
Re: Tales from the Wobbly Workshop
« Reply #215 on: August 01, 2014, 11:08:13 am »
An electric uke? That is just wrong in so many ways.

(I will confess to late night browsing of UOGB on you tube, Teenage Dirtbag is a bit of a favourite)
216km from Marsh Gibbon

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: Tales from the Wobbly Workshop
« Reply #216 on: August 01, 2014, 06:34:26 pm »
An electric uke? That is just wrong in so many ways.

(I will confess to late night browsing of UOGB on you tube, Teenage Dirtbag is a bit of a favourite)

They did "Teenage Dirtbag" last w/e.  Did it all over Wheatus from a great height :thumbsup:

The electric uke sounds teh awsum.
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

Re: Tales from the Wobbly Workshop
« Reply #217 on: October 22, 2014, 11:41:45 pm »
Let's start a new project.  :thumbsup:

I need a weight for this project, and it might as well be made of lead.

A collegue keeps tropical fish, and has saved all the little weights that used to hold plants down...

... a cat-food tin & a bunsen burner and I'm ready to go.  :thumbsup: :thumbsup:



Soon, under all the slag, there is liquid metal...     8)



...which can be poured into an aluminium beaker.



The lead dosn't stick to the aluminium, so when a bit cooler and solid, it can be popped out.  :D



In the workshop, I drilled it to take a machine screw - it's on the bench here with some aluminium castings the students were doing with me on Friday (noughts & crosses games for marbles).  :smug:



Who can guess what the project is before you see the result at the weekend?  :demon:

If it ain't broke, fix it 'til it is...

Re: Tales from the Wobbly Workshop
« Reply #218 on: October 23, 2014, 12:22:19 am »
A balance weight for a microphone boom?

Re: Tales from the Wobbly Workshop
« Reply #219 on: October 23, 2014, 06:41:24 am »
A cyclists shillelagh? ( Possibly designed to test the reaction times of bad drivers)

Re: Tales from the Wobbly Workshop
« Reply #220 on: October 23, 2014, 06:59:29 am »
a weight to help keep a no-hands-required-umbrella in place when bivvi-ing

love the noughts and crosses for marbles  :thumbsup:
not so much a gravel grinder.... more of a gravel groveller


Re: Tales from the Wobbly Workshop
« Reply #221 on: October 23, 2014, 07:41:01 am »
Is that some sort of strap dangling from the construction? 

Looks like a brolly handle or a walking pole.

Re: Tales from the Wobbly Workshop
« Reply #222 on: October 23, 2014, 08:12:12 am »
love the noughts and crosses for marbles  :thumbsup:

It's great to have access to all the equipment and techniques at work - it would probably be of interest if I showed more on this thread.

For the marbles game: The patterns were machined on a CNC router (I'm the department's 'expert' and worked with the students to acheive this). Sand moulds are made and aluminium from a crucible furnace is poured in (again, I'm supposed to be the 'expert'  ::-)). The games will also have a hardwood box made to keep them in.  Oh, and guess who had to come up with the idea for the project.  :smug:


BTW, a couple of weeks ago we added a 3D printer to our range of equipment.  :D
If it ain't broke, fix it 'til it is...

Re: Tales from the Wobbly Workshop
« Reply #223 on: October 23, 2014, 08:28:00 am »
You're making a life-sized, human-ridden version of one of these and I look forward to seeing the video of you demonstrating it in your back garden.

(click to show/hide)

Vince

  • Can't climb; won't climb
Re: Tales from the Wobbly Workshop
« Reply #224 on: October 23, 2014, 09:52:42 am »
Its a camera stand to keep the camera level whilst cornering at speed.
216km from Marsh Gibbon