Author Topic: How to mend this tripod? (with tap and die set)  (Read 3322 times)

Ben T

How to mend this tripod? (with tap and die set)
« on: 03 April, 2018, 03:58:02 pm »
I have managed to break my travel tripod by hamfistedly pulling the rod that the head goes onto clean out, stripping the threads.
I was thinking I could just use a tap and die set to drive a new piece of 3/8" rod into it but am confused:

a) why is there two measurements on each tap, so for instance would the middle one labelled 5/16" / 7/16" create a thread 6/16" depending how far I drove it in? They are tapered towards the end so the deeper it goes the wider the thread it will cut.

b) if that's the case, then why is that particular bit obviously too small? It fits in the hole with room to spare, and the hole is not big (see comparison with little finger for scale), certainly looks less than 3/8".

have got a replacement tripod but would like to mend this mini tripod if possible as it was a present, and also the new one is noticeably less 'mini'.

IMG_20180403_152018 by Ben Taylor, on Flickr

IMG_20180403_151907 by Ben Taylor, on Flickr

IMG_20180403_151812 by Ben Taylor, on Flickr

Re: How to mend this tripod? (with tap and die set)
« Reply #1 on: 03 April, 2018, 05:24:52 pm »
It is not too clear to me what you are trying to do but they look like stud extractors rather than taps.  The combination of a left hand thread and a taper allows them to be screwed into a hole that has been drilled in the end of a broken stud, get purchase on it and wind it out.  I am guessing that the 5/16" / 7/16" one is small enough that it can be used to remove studs within that range of outside diameters.

Re: How to mend this tripod? (with tap and die set)
« Reply #2 on: 03 April, 2018, 05:25:56 pm »
Those might be screw extractors not taps.

Feanor

  • It's mostly downhill from here.
Re: How to mend this tripod? (with tap and die set)
« Reply #3 on: 03 April, 2018, 05:28:43 pm »
Exactly. Those are Easy-Outs, not taps.

They have a coarse tapered Left-hand thread.

Ben T

Re: How to mend this tripod? (with tap and die set)
« Reply #4 on: 03 April, 2018, 08:33:26 pm »
ok so if they are screw extractors... they might not be useful.

But still, what would it take to attach a head to the tripod... would it work to simply get an actual 3/8" tap, tap a thread into the hole, and wind a short section of 3/8" threaded bar into it?
Any potential problems foreseen with that?

Re: How to mend this tripod? (with tap and die set)
« Reply #5 on: 04 April, 2018, 01:37:34 am »
As everyone else has said, they're not taps. Even if they were, I doubt they'd be much use - if you've pulled the rod out and stripped the thread, recutting it won't help much.

If it was in metal you might have some luck fitting a helicopterhelicoil, but in plastic I'd be more inclined to epoxy in a new length of threaded rod.

Aunt Maud

  • Le Flâneur.
Re: How to mend this tripod? (with tap and die set)
« Reply #6 on: 04 April, 2018, 08:34:37 am »
snip......

If it was in metal you might have some luck fitting a helicopter..../snip

I don't think you'll have much luck getting a whole helicopter in there, it's too small.

PaulF

  • "World's Scariest Barman"
  • It's only impossible if you stop to think about it
Re: How to mend this tripod? (with tap and die set)
« Reply #7 on: 04 April, 2018, 08:50:38 am »
snip......

If it was in metal you might have some luck fitting a helicopter..../snip

I don't think you'll have much luck getting a whole helicopter in there, it's too small.

Something like this might work



However I suspect that jsabine fell victim to autocarrot and meant Helicoil?

Ben T

Re: How to mend this tripod? (with tap and die set)
« Reply #8 on: 04 April, 2018, 09:47:08 am »
As everyone else has said, they're not taps. Even if they were, I doubt they'd be much use - if you've pulled the rod out and stripped the thread, recutting it won't help much.

If it was in metal you might have some luck fitting a helicopter, but in plastic I'd be more inclined to epoxy in a new length of threaded rod.

Yes, but, the old length of rod that went into the hole wasn't a single 3/8" length of threaded rod. i.e. it's not a 3/8" thread that's stripped. The bit that went in that has now stripped was narrower than 3/8", I think, so it may still be possible to cut a 3/8" thread?

Re: How to mend this tripod? (with tap and die set)
« Reply #9 on: 04 April, 2018, 01:02:06 pm »
snip......

If it was in metal you might have some luck fitting a helicopter..../snip

I don't think you'll have much luck getting a whole helicopter in there, it's too small.

Something like this might work



However I suspect that jsabine fell victim to autocarrot and meant Helicoil?

Possibly, possibly ...

It's always nice when folk can read what you meant, not what you actually said.

Re: How to mend this tripod? (with tap and die set)
« Reply #10 on: 04 April, 2018, 01:18:59 pm »
As everyone else has said, they're not taps. Even if they were, I doubt they'd be much use - if you've pulled the rod out and stripped the thread, recutting it won't help much.

If it was in metal you might have some luck fitting a helicopter, but in plastic I'd be more inclined to epoxy in a new length of threaded rod.

Yes, but, the old length of rod that went into the hole wasn't a single 3/8" length of threaded rod. i.e. it's not a 3/8" thread that's stripped. The bit that went in that has now stripped was narrower than 3/8", I think, so it may still be possible to cut a 3/8" thread?

Fair enough. Try the hole with a 5/16in drill bit, and if the bit is either too large or a tight fit, then there should be enough meat to let you cut the new thread.

Given there won't be a shoulder on your rod to stop it screwing in too far, I'd probably find some way of fixing it in place - maybe just threadlock.

David Martin

  • Thats Dr Oi You thankyouverymuch
Re: How to mend this tripod? (with tap and die set)
« Reply #11 on: 05 April, 2018, 08:15:52 pm »
I'm presuming that you have stripped a 1/4" whitworth thread (standard 6mmish camera thread). There are a couple of wider threads in common use - I think the next one up is 1/2" whitworth and adaptors are readily available. So you should aim to cut a thread that will take the adapter and then your threaded rod will fit.
Or fit a helicoil.
Or fit in place with epoxy/sugru whatever. Sugru is slightly flexible so may be better than a hard epoxy.
"By creating we think. By living we learn" - Patrick Geddes

andytheflyer

  • Andytheex-flyer.....
Re: How to mend this tripod? (with tap and die set)
« Reply #12 on: 07 April, 2018, 04:32:22 pm »
I'd find a backstreet machine shop and give them the tripod and the bit you pulled out. They'll fix it if its fixable.  You spend some £ but you'll get a hassle free fix.  Drilling out and tapping means that you need the right sized drill to suit the new tap, and you may need more than one tap if the hole is blind at the bottom. 

It's all do-able, but the drill and taps and tap wrench will cost a few £, and you'll only use them once. It's also very do-able to screw up the tapping so that the tripod really is stuffed.  If you buy a cheapish tap set, and then break it off whilst tapping (DAMHIKT) you'll be chucking away tripod and taps.

It's very satisfying and you'll get a warm glow from getting a man in a shed to fix something like this, it gives you faith in our species to fix things that some would discard and buy new.  It might even be cheaper to get it fixed.

Have a look for Abom79 and Keith Fenner on YouTube if you want to see how the pros do it - mesmerising!

Ben T

Re: How to mend this tripod? (with tap and die set)
« Reply #13 on: 07 April, 2018, 07:52:45 pm »
Yeah I might do that actually, it probably would be quite satisfying.
I found some that actually are taps rather than screw extractors but only an M8, which is metric not imperial, so I'd have to order 3 things - a piece of threaded bar, a tap and maybe a drill bit, either of which could be wrong.

Unfortunately I don't think I retained the bit that came out, so I think it might a case of finding a machine shop that's got some threaded bar.

Re: How to mend this tripod? (with tap and die set)
« Reply #14 on: 08 April, 2018, 12:51:37 pm »
This is hardly high precision engineering, you just need to attach the tripod head to the legs.

If you don't need interchangeability with other heads or tripods, use a M8 tap to cut new threads, you might need to drill out the existing hole to the right diameter for the tap. Then cut down a M8 screw to the right length, screw that to the tripod.

Depending on the tripod design, you might only need to cut one thread or none at all and use a bolt with a nut.

Ben T

Re: How to mend this tripod? (with tap and die set)
« Reply #15 on: 08 April, 2018, 02:26:41 pm »
yeah, but, the tripod has a central pole that goes down so I can't screw into it from the bottom of the head (or attach a nut), and I would rather the ability to take the head off and put it on my gorillapod.

Re: How to mend this tripod? (with tap and die set)
« Reply #16 on: 08 April, 2018, 03:09:12 pm »
The simplest way would be to glue the threaded rod (either the original or a replacement) back in the hole with epoxy.


Ben T

Re: How to mend this tripod? (with tap and die set)
« Reply #17 on: 08 April, 2018, 03:16:20 pm »
It would be the simplest but it wouldn't be strong enough, it wouldn't hold when I screwed the head on. Would it?

Re: How to mend this tripod? (with tap and die set)
« Reply #18 on: 08 April, 2018, 04:32:05 pm »
Epoxy's pretty strong, I would have thought, look at all those carbon bike bits...all held together with epoxy.

The existing threads will also help stop the rod from pulling out. If you're really worried, you might:

drill holes from the side and put screws in so they hold against the threaded rod,

add fabric to the epoxy to reinforce it.


Ben T

Re: How to mend this tripod? (with tap and die set)
« Reply #19 on: 08 April, 2018, 08:53:29 pm »
hmm, ok. worth a try I suppose, thanks.