Tripod Ring Repair ?

I over tightened the stud on my tripod last night and broke the bushing in the tripod ring. It actually broke pretty easy when I rotated the lens an 1/8 turn to snug it up. Anyway I called Canon tonight and the parts department said that only the ring is available (for about $150) and not just the bushing, which is easily replaceable i.e.: two screws on top of the "foot". Anyone ever have this problem ? or know where to get a replacement bushing ? Lens is a 100-400 IS L

Sorry to hear that.I broke my tripod collar too i wore a notch in mine i have the 400 prime.Its not the same without it.Goodluck

Diver-Down wrote in post #6268238
I over tightened the stud on my tripod last night and broke the bushing in the tripod ring. It actually broke pretty easy when I rotated the lens an 1/8 turn to snug it up. Anyway I called Canon tonight and the parts department said that only the ring is available (for about $150) and not just the bushing, which is easily replaceable i.e.: two screws on top of the "foot". Anyone ever have this problem ? or know where to get a replacement bushing ? Lens is a 100-400 IS L

if you constantly overtighten a bolt or screw the effort will seem pretty easy when it finally fails.

ed rader

I do not know if your tripod ring is a "a" or a "b" type - look on the little oval plate on the ring...

E-bay has sellers with aftermarket rings for far less than the $150 Canon ring. Might want to try that.

If you're handy, you could probably make a new bushing.

If you live in a fair size city, take it to a machine shop. They might be able to fix it.

gasrocks wrote in post #6271977
If you live in a fair size city, take it to a machine shop. They might be able to fix it.

A good auto repair shop may also be able to help.

If all you did was to strip or pull the threads out, a threaded insert could be a reasonable repair. I don't think there is enough material to install a heli-coil, but there may be enough for a nutsert. I'm not positive and don't want to do a destructive test, but I think the threads on the Canon Tripod Ring are aluminum. Good luck with the repair.

Jeff

jdkeck wrote in post #6276428
A good auto repair shop may also be able to help.

If all you did was to strip or pull the threads out, a threaded insert could be a reasonable repair. I don't think there is enough material to install a heli-coil, but there may be enough for a nutsert.

Or better yet, an automotive machine shop.

A helicoil doesn't need much extra diameter. If you're handy with tools you can install one yourself - you just drill out the hole to the specified size and re-tap the hole with the special tap that comes in the helicoil kit. Smaller size kits run about $25-35 last time I bought any.

-js

The tripod ring is aluminum then it has a steel bushing insert. The steel bushing insert broke off the cap that it is attached to. I think that the hole is already too big to put a heli coil into because I really need to stay with the same size threads so I can still use the mounting hardware for my tripod.

I suppose I could epoxy the broken part of the bushing into the hole but it fits very tight and I doubt that it would hold enough to trust. I tried calling all around Canon again today but no one could help me short of buying a new ring. Guess I'll have to come up with some sort of repair.......

personally, I'd be spending the $150 for a new ring. The cost of repairing a 100-400L and body if it hit the deck (or worse) due to a dodgy helicoil/epoxy repair would exceed that by quite a bit...

Diver-Down wrote in post #6282482
The tripod ring is aluminum then it has a steel bushing insert. The steel bushing insert broke off the cap that it is attached to. I think that the hole is already too big to put a heli coil into because I really need to stay with the same size threads so I can still use the mounting hardware for my tripod.

A helicoil restores the original thread size. But I'm not getting the picture here - how about a photo?

Epoxy is a risky way to repair threads. I agree with joeseph on that. OTOH, a helicoil is stronger than the original threads if they were tapped in aluminum.

As any machinist will tell you, there are a hundred ways to do anything. Perhaps an insert is required?

-js

If the insert is a cylindrically symmetric part, you may be able to get a replacement part machined at a reasonable cost. Take the pieces to a machine shop and get their opinion.

Jeff

From the measurements I could make without taking the insert out of the foot, it looks like a 1/4-20 Thread-Sert (the Marson Brand) could be installed. The drill size for the insert is 25/64" (0.390") and the hole is less than 0.34".

Jeff

Thanks for measuring that Jeff, I guess I'll give the helicoil a shot but if it doesn't work out 100% I'm not going to use it and risk the lens falling off. I'll probably keep an eye out on e-bay as well, I would just rather not hang a piece of L glass off one of those cheap o rings.

A thread-sert is not a heli-coil. I don't have the specs for heli-coil inserts. This is a thread-sert, http://www.huck.com/ma​rsoncorp/threadsert.ht​m . They come in both aluminum and steel. A special tool is needed to compress the insert that may not be worth a one time use. A machine shop, either regular or auto, should have the tools. On the other hand, they are very handy for repairs. In addition to the thread-sert style, there is a rivet style that is designed for use in thin materials.

Jeff