PD Tripod Mount Stuck

sep9001

sep9001

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Kev
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Hi

Help please. Any idea what I can do to remove the PD Tripod mount from the bottom of a 70-200 tripod mount?

Thank you
 

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Few ideas to try...

- WD40 or similar and let it soak before trying to undo the bolt.

- Sounds a little odd, but try tightening the bolt tiny amount, then try to undo it again.

- Try holding the plate in a vice and try to turn the collar instead. (Becareful not to bend the collar).

- You could try applying a little bit of heat to the bolt. (Last resort). Also be careful if you've applied oil before.
 
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Looking at the picture it us hard to see how stripped the Allen key hole is?

As for the damage to the 'slot' edges.....well IMO that typical happens when using too small a flat bladed screwdriver......I often use a 20p coin as I have found that a good fit 'when needed'.

To remove it.....worse case use would be a sheared bolt extraction tool. This works by cutting its own thread to then unscrew the seized item.
 
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Gav. said:
Few ideas to try...

- WD40 or similar and let it soak before trying to undo the bolt.

- Sounds a little odd, but try tightening the bolt tiny amount, then try to undo it again.

- Try holding the plate in a vice and try to turn the collar instead. (Becareful not to bend the collar).
Click to expand...
My concern with that would be twist damage to the collar mount point especially if it is 'heli-coil' type design?
Gav. said:
- You could try applying a little bit of heat to the bolt. (Last resort). Also be careful if you've applied oil before.
Click to expand...
 
Try to cut the slots deeper, something like a Dremel with a cutting disc would be handy.
Then a correctly sized flat screwdriver should work
 
If all the above suggestions fail, then a favoured trick of mine is to heat the whole item about 50 degrees and then use a freezer spray on the bolt. The heat will expand the whole thing and then the freezer will shrink the bolt. They should then separate quite easily.
 
Sky said:
If all the above suggestions fail, then a favoured trick of mine is to heat the whole item about 50 degrees and then use a freezer spray on the bolt. The heat will expand the whole thing and then the freezer will shrink the bolt. They should then separate quite easily.
Click to expand...
Heat alone should work; the two metals have very different heat expansion/transmission properties.
The bolt has probably corroded to the foot. Stainless and aluminum are pretty far apart on the galvanic corrosion chart.
 
sk66 said:
Heat alone should work; the two metals have very different heat expansion/transmission properties.
The bolt has probably corroded to the foot. Stainless and aluminum are pretty far apart on the galvanic corrosion chart.
Click to expand...
I would have thought that the both the bolt and the tripod hole thread were made of steel i.e. the tripod mounts are steel (heli-like?) inserts in the alloy of the foot.
Plus IIRC the same applies (these days?) to the body tripod mounts :thinking:
 
chrism8 said:
Looking at the image, I'd go for a coin in a pair of decent pliers
Click to expand...
Worth a try and as I said in post #3 a 20p coin often fits such slotted bolts used on photo gear.
 
Thank you all for the suggestions.

Tried the coin trick and freezer but neither worked, will have a look at the other options over the next few days.
 
Seeing a white tripod ring I surmised Canon and looked to learn(?) that on that type the hole as @sk66 said looks like it is drilled and tapped into the alloy metal, so it could be galvanic corrosion?

Having said, the design seems to show a small round plate on the opposite side of the foot held in by a couple of small screws. ......I wonder what is revealed if that plate is removed?

Though of note your gear list shows only Nikon and IIRC their lenses are all black!
 
Box Brownie said:
Seeing a white tripod ring I surmised Canon and looked to learn(?) that on that type the hole as @sk66 said looks like it is drilled and tapped into the alloy metal, so it could be galvanic corrosion?

Having said, the design seems to show a small round plate on the opposite side of the foot held in by a couple of small screws. ......I wonder what is revealed if that plate is removed?

Though of note your gear list shows only Nikon and IIRC their lenses are all black!
Click to expand...

Yep I am a Nikon user, issue has happened on a friend’s canon lens tripod mount.
 
sep9001 said:
Yep I am a Nikon user, issue has happened on a friend’s canon lens tripod mount.
Click to expand...
Ah! helping out a friend......good egg :)

Any more aggressive methods, depending the tools to hand or needed, could potentially damage the foot in a minor way (possibly major?). Have you got carte blanche to do anything you can to remove it?

Re: my suggestion to remove the small plate (I was visualising that it would reveal the end of the thread = allowing for e.g. using WB 40 or other penetrating 'oil' or even a directed use of freezing spray) to help free it?

Though perhaps a phone call to Fixation and ask them about this? Or wing it and be ready for what you find happens :thinking:

Best of luck sorting it out:)
 
Have you tried twisting the tripod mount, as if you were undoing it. Unless there are some sort of locating tabs that should loosen the bolt.
 
Going to try WD 40, if that does not work we will leave the PD plate on, don’t think it is worth damaging the lens tripod mount.

Thank you
 
sep9001 said:
Going to try WD 40, if that does not work we will leave the PD plate on, don’t think it is worth damaging the lens tripod mount.

Thank you
Click to expand...
Thanks for the update.

Just a further thought, as mentioned I don't ever recall a an Allen slip and damage the hole it goes into (on the surmise the exact size key was used). In other words 'how the heck did your friend make it so tight'?

Setting aside Galvanic corrosion being a cause, did the friend use anything to lock it in place such as the, permanent, Red Loctite?
 
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Box Brownie said:
Thanks for the update.

Just a further thought, as mentioned I don't ever recall a an Allen slip and damage the hole it goes into (on the surmise the exact size key was used). In other words 'how the heck did your friend make it so tight'?

Setting aside Galvanic corrosion being a cause, did the friend use anything to lock it in place such as the, permanent, Red Loctite?
Click to expand...
No idea how it became so tight.
 
Ended getting another plate as did not want to damage the lens foot.

When the new one arrived and I put it on the body , although is was clean it felt quite tight, is it worth putting on some graphite grease on the screw so we do not have this issue in the future?

Thank you
 
sep9001 said:
is it worth putting on some graphite grease on the screw so we do not have this issue in the future?
Click to expand...
No harm in doing so, provided the body has a Brass or Stainless insert. (Some greases speed up issues in Aluminium.)

Only real downside is mess.

Just check it once in a while to check it's not loosened, and go easy tightening it as the grease will 'hide' some of the torque your applying and make it easier to over tighten.
 
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Gav. said:
No harm in doing so, provided the body has a Brass or Stainless insert. (Some greases speed up issues in Aluminium.)

Only real downside is mess.

Just check it once in a while to check it's not loosened, and go easy tightening it as the grease will 'hide' some of the torque your applying and make it easier to over tighten.
Click to expand...
Thank you, may just leave it for now.
 
WD40 isn't a dismantling spray, for that you need PlusGas.
Used it all the time when I rebuilt retro mountain bikes, spray and leave overnight
 
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