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Message |
    
Alex
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 14, 2005 - 06:58 am: | 
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One of my Yashica lenses (which was not new when I bought it) never transmitted aperture information to the camera, and now I see why. There's a little projecting lever on the rear of the lens mount, held on by two tiny screws, which is meant to engage with a similar lever in the camera lens throat. Only it's not there. I only noticed it was missing by comparing it with similar lenses. So I reckoned I could cannibalise a junk lens, and remount the little aperture information lever on the Y28ML. One of the screws wouldn't go in, and on closer inspection, I see that in one of the holes there is the tip of the screw that used to be there. I'm guessing that this little lever existed at one time and was somehow forced off by some kind of accident. I can keep the cannibalised lever in place on the lens with just the one screw, but I'd really like to remove the screw tip lodged in the other hole. It looks like I'll need to take the rear plate off the lens, but I'm not sure how I'm going to get this screw out once I've done that, because there's no head to engage a crosspoint in, and it's a very, very tiny screw (is there any other kind in a camera?). If anyone has encountered a similar problem before, I'd be grateful for pointers. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 14, 2005 - 09:00 am: |
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Sometimes if you use an ordinary miniature screwdriver, you can turn the stub out enough to grip with pliers etc. The screwdriver you use, should be one with a hardened blade so that you can apply some 'grip' to the stub. If stub is of sufficient diameter you can use a hardened fine steel point to try and turn the broken bit.This does not work well on small diameters - you cannot get the required turning moment.
However; having suitable drilling equipment means that I personally tend to drill the things out,if I come across an awkward beast. |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 14, 2005 - 10:15 am: |
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I noticed recently that my local NAPA auto parts store has left-hand-twist drill bits in a whole range of sizes. These are made for drilling out screws that are too small for an EZ-Out extractor: in many cases, the drill will go partway in and then catch, and the screw will unscrew out of the hole. If it doesn't, you end up drilling it out as with a regular bit. One of these would definitely be worth a try, I'd think.
Remember to set your drill to spin backwards..... |
Alex
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 14, 2005 - 02:56 pm: |
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Thank you, chaps, it looks like drilling is the way to go. Golly, this isn't half a learning experience! |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 14, 2005 - 08:15 pm: |
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If left-hand drill bits are not available you can make miniature spade bits from silver-steel rod.Grind/file the relief for anti-clock rotation and then harden right out.Polish and temper to a light straw colour.Drill out using a slow speed and light feed.These will also pick up/catch in many instances,unscrewing the stub in the process.
The advantage of a spade bit, when filed up properly,is the less risk of damaging the threads when the bit is not parallel with the tapped hole.This is because the spade bit will only have it's cutting edge on the end.The flute edges on a twist bit can damage the wall of the hole if not parallel to same.
Here in the UK left hand drill bits in small sizes ie 1.5mm to 3mm are not that readily available,except from specialised dealers.So the spade bit is usually the simplest way out of the problem. |
Henry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 14, 2005 - 09:26 pm: |
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Ok, here is what I do...being a drill press freak.
I grind a sharp hardened screwdriver bit, in fact I grind out the center leaving only two points at the outer tips. Then chuck it up in a drill press and with lots of down pressure indent the screw root diameter. Finally just screw it out by hand.
Henry |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 15, 2005 - 10:06 am: |
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Henry,
Very sophisticated method! Just shows there is more that one way to skin the cat. With apologies to all the cat lovers out there.
Glenn |
Henry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 16, 2005 - 09:08 am: |
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If one is dextrous enough and have strong enough fingers the drill press could be ignored. I am neither dextrous nor strong. Anyway, the drill press allows for dead-on alignment...which is very important. My drill press has a two axis bed and special wood covered with thin carpet "camera" jaws.
Henry |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 18, 2005 - 10:25 am: |
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Hi Henry:
I have a few screwdrivers that I've done the same with, and use them for both broken screws and pushing spring ends onto their anchors. I've had pretty mixed results with them as screw extractors, but I haven't tried the drill press angle.....
: ) = |
