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Harv
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 23, 2005 - 04:30 pm: | 
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Quick question about screwdrivers for dealing with those wicked tiny screws in cameras & lenses. Do Phillips tips come any smaller than 000? I've looked at a couple of suppliers online, including Micro-tools, and that's their smallest size. I've got a lens to tackle and some of the screw heads are about 1 mm in diameter.
Harv |
Peter Wallage
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 23, 2005 - 05:10 pm: |
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Hi Harv,
I came across the same problem some time ago. I too was unable to find a cross-point driver small enough for some screws I needed to undo, so I modified a plain blade-point driver. Not ideal I know, because it grips in only two of the recesses in the screw head instead of four, but it worked and I've used it several times.
What I did was to take the thinnest blade-point driver from a cheap and cheerful market-stall set of "instrument screwdrivers". I've just measured it, and the blade is exactly 1mm diameter. I let down the hardness of the blade by heating it with a butane pencil-torch to a dull red and letting it cool naturally in air.
Then I shaped the point to a vee spear shape with a very fine-tooth file till it fitted in the screws I wanted to undo, then hardened it by heating it to bright red and quenching in oil. The type of oil isn't critical, I used some car engine oil in an old film container.
Hardening by itself would have made the blade too brittle, so I tempered it. I cleaned it with some fine rubbing-down paper, held the flame of the pencil butane torch about half an inch or so behind the tip and watched the colours travel up the blade. As soon as the blue colour reached the tip I quenched it again in oil. The colours travel quite quickly so you have to keep a sharp watch on them.
I used the term cross-point rather than Phillips because some Japanese cameras, notably Canon, don't use a Phillips type cross head. Their cross head is shallower and at a broader angle, and the cross slots are thinner.
I also made some drivers in the same way as above to fit several sizes of Canon cross-head screw. As I said, not the ideal tools, but mine work and so far, touch wood, I haven't chewed up any screw heads.
Hope this is of some help.
Peter |
Harv
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 23, 2005 - 07:18 pm: |
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Peter: thanks for the info. It answered another question I had and that was the difference between Phillips and Cross-point tips. I was looking at the Micro-tools catalogue online and they carry the cross-points which are made in Japan! I'm going to tackle a Pentax lens so maybe it's a safe bet that's what's holding it together. I'm going to try your trick though.
Harv |
charlie
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 24, 2005 - 06:49 am: |
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Posi-Drive is an alternative to Phillips and is less apt to twist out of the screw head but I am not sure how small they come. I have a similar problem trying to access a broken delrin gear in an Oly Trip 35. |
M Currie
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 24, 2005 - 08:09 am: |
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I've done the same as Peter above, reshaping cheap little drivers, or ones that have already been chipped. I don't usually heat treat the head, but use a carborundum stone rather than a file to shape it. I've also found that even less-cheap little screwdrivers benefit from occasional dressing with a stone. Natural stones don't work well for this, but a not-too-fine carborundum stone does. Often the straight slots in camera gear are very thin, and it helps a lot to get the widest possible blade into them. |
Jim Murray
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 24, 2005 - 02:54 pm: |
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I had a frustrating time finding a phillips screwdriver for my Canon FTb. 000 does appear to
be the smallest size, but I believe a standard
either doesn't exist or isn't followed. I bought
several different brands of 000 that were too
large to fit. I finally stumbled on a german WIHA
that fits like it was made for the job. I believe
that I bought it mail-order from MSC or McMaster-
Carr. |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 24, 2005 - 05:57 pm: |
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I think you will find it is better to purchase crosspoint drivers by their shaft diameter, rather than o,oo,ooo designations.Here in UK most good quality, non interchange bit drive sets are identified by diameter. This means that most sets have a size smaller than ooo. Typical smallest diameter appears to be 1.3/1.4mm. As a note of interest MAPLINS UK sell a miniature crosspoint set dirt cheap - 5 drivers with well formed, well tempered blades for around £2.00! They work well,especially as smallest size is as above.The only problem I can see is that using largest size on a well tightened screw might loosen blade in handle; as plastic handles are a bit slender.This does not bother me as I only purchased a couple of sets for small sizes, where the torque involved is low.This set works well on all Canon A,F and T series.I hope you all have a good Easter break Regards Glenn |
Peter Wallage
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 24, 2005 - 06:06 pm: |
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As a warning, don't get Phillips and Posidrive screws mixed up. They are NOT the same. The screwdrivers are not interchangeable.
So far I haven't come across Posidrive screws on cameras, but you often find them on electrical equipment and children's toys.
For a rather racy, but accurate, rundown on the differences between Phillips and Posidrive take a look at
http://www.shadetreemg.com/posidrive.htm
Peter |
charlie
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 25, 2005 - 07:01 am: |
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I think Posi Drives are used where high torque is needed. A Phillips with its tapered flanks will just climb up out of its head. The Posi Drive has vertical flanks and has no tendency to climb out of the screw slots (which also have vertical flanks) when a lot of torque is applied. |
Harv
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 27, 2005 - 09:29 am: |
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Thank you all for your input. It never occurred to me when I raised this question that what looks like a Phillips isn't necessarily a Phillips. These screws I'm looking at are 1 mm in size so I need to get it right.
Harv |
