| Author |
Message |
    
Bruce_robbins
Tinkerer
Username: Bruce_robbins
Post Number: 7
Registered: 06-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 05, 2013 - 02:49 am: | 
|
I had to drill the head off a chewed up screw on the lens mount and I'm now left with little more than 2mm of stump protruding from the lens body. I've tried getting a firm hold with a pair of pliers but wasn't too successful. Since I'll only have a couple of goes to remove the screw before the stump breaks, is there a better way of doing it? |
Zombicams
Tinkerer
Username: Zombicams
Post Number: 11
Registered: 12-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 05, 2013 - 06:35 am: |
|
Get a Dremel with a thin cutting disc, cut a slot into the stump, remove with screwdriver. |
Hi_country_flash
Tinkerer
Username: Hi_country_flash
Post Number: 12
Registered: 12-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 05, 2013 - 11:23 am: |
|
If it is as small as most lens mount screws, a Dremel disk ( .025 thick) will be far too much, and will probably not help. If there is a Dental lab. near you , contact them and see if they have a cutting disk from Keystone that is thinner , some are made that are as little as .005 thick.
Could you possibly solder a "handle" on the screw stump at right angles to it? |
Glenn
Tinkerer
Username: Glenn
Post Number: 1054
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 05, 2013 - 12:15 pm: |
|
What lens is this? The thread type is all important - ie in the Canon nFD mount the radial retaining screws have a thread type that binds in the drilling, thus the stump will not rotate freely. On the other hand in screws that have a normally cut or rolled thread, once the head is cut off all tightening torque is removed and the stump should be free to rotated. You should apply some heat via a large soldering iron, before applying the pliers - the pliers should have the end ground off to produce perfectly even and aligned jaw ends. |
Bruce_robbins
Tinkerer
Username: Bruce_robbins
Post Number: 11
Registered: 06-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 05, 2013 - 03:34 pm: |
|
Lots of good advice here. Thanks very much. The stump is only about 3mm in diameter - it's an OM lens. There was a small hole in the middle of it from drilling. I pinched the stump to try to deform the hole into a slot that would take a small screwdriver but the "walls" aren't strong enough to take the torque. It's looking very much as if I wont be able to unscrew it now and might have to think about drilling the stump out. Don't fancy that at all and don't have the equipment either. |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 298
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 05, 2013 - 03:39 pm: |
|
Best bet is drilling the stump all the way through using a drill that is slightly smaller that the screw. Once you get through then using a dental pick you cna remove the walls left n that will expose the threads..
you'll need ot chase the old threaded hole out with a tap or use a new screw wit the tip grount to a point as a starter.
. |
Aerowoof
Tinkerer
Username: Aerowoof
Post Number: 75
Registered: 02-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 05, 2013 - 05:02 pm: |
|
I had a similar problem but not on a camera and was able to find an allenwrench that would just fit inside the hole and used some thick super glue and let it cure for 24 hours even tho it was supposed to be instant so to speak and i was able to unscrew it . |
One90guy
Tinkerer
Username: One90guy
Post Number: 42
Registered: 07-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 05, 2013 - 06:59 pm: |
|
Did you use vicergrip pliers. I have one that is needle nosed. Good luck, wish I had better advice. |
Bruce_robbins
Tinkerer
Username: Bruce_robbins
Post Number: 12
Registered: 06-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 06, 2013 - 03:41 am: |
|
Aerowoof,
Might try your allen key approach - certainly nothing to lose! Thanks for that. |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 495
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 06, 2013 - 07:20 pm: |
|
A left hand drill bit is best for removing screw stumps. After that, a "back-out" works good. Lastly, what Paul_ron said. A drop of acetone on the stump should loosen most thread locker glues.
PF |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1284
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 09, 2013 - 02:36 pm: |
|
Ditto Br... I picked up a set of small left-hand drill bits at Harbor Freight pretty cheap. With a LH drill, when it starts to bit it will tend to loosen the screw rather than tighten it. Start small and work your way up until it either backs out or get so thin that you can pick it out. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 78
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 10, 2013 - 07:28 am: |
|
Try this. Find a rod abt the size of the drill u use that will go in to the hole. Apply Araldite(Ciba) or similar compund to glue the the rod in the hole. Once it setts ater 24 hrs you can handle it as you like. If you can trasmit some vibrations to the lense such as from a beard trimmer it might make it easier to get loosend
while you try to take it out.
I did try some similar methods on a bigger bolts where icd weld a 8mm rod inside a hole to take out the stuck broken bolts inside threaded holes.
I did try out gluing some thing to get better hold of small scres too. |
Premoutshine
Tinkerer
Username: Premoutshine
Post Number: 2
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 11, 2013 - 06:51 am: |
|
I was facing the kind of same problem .Thank you folks for lovely suggestions.  |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 79
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 13, 2013 - 11:00 am: |
|
I did use this technique when i accedentally dropped a ball in to the hole presumeing thre is spring inside but it wasnt. The ball was less than a millimeter, thought it was llose inside it was inacccesible. I aapplied a trace of instagluie to the tip of a wire and pulled it up. Bu this is a case where no force was needed to pull it out. |
