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Agfaclack
Tinkerer
Username: Agfaclack
Post Number: 1
Registered: 09-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 06, 2012 - 06:26 pm: | 
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I've soaked my Prontor SVS shutter in a few different things now (Coleman fuel, Liquid Wrench, MEK and denatured alcohol). The screws that hold the shutter-body on, and the ones for the timer escapement, etc, are stuck. I'm afraid of mangling them. Does anyone have a suggestion for loosening them up?
Currently the shutter halts on its way to closing; maybe I have cleaning residue where the shutter-blades are pinned. Seems close to working.
It's a "learning experience" - fixing the Ansco Speedex I had when I was a kid. |
Brcamera
Tinkerer
Username: Brcamera
Post Number: 216
Registered: 08-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 07, 2012 - 08:52 am: |
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Some Prontor screws have shallow slots so it is critical to have a screwdriver blade that fits perfectly. With the correct blade, these screws should release. You might have to modify/file your blade. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 56
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 07, 2012 - 12:30 pm: |
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Well all my screw drivers baught in market do not fit Japanese screws snugly. As a result if a screw is stuck it becomes very difficult to unscrew them.
Years back i did the same thing, like filing and fittingnthe screw driver to the screw. The job isnt easy and difficultt to get a good fitting. Then i stuck up on an idea if forging the tip into agood screw. I fitted a screw in to a metal plate, rested the plate on a sloid support, then put the tip of the screw driver into it and hammerd it gently. But before putting it thre i did heat it up red hot. In the end i got such good screwdriver now that any screw that doesnt budge with other screw drivers, I use this one.
I am not sure how far the idea is useful to othres, but my work almost stops without my spl screwdriver when i am stuck with an adamant screw.
In your case of course the screws arent japanese and I hv no experince with german corss headed screws. screws |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 159
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 07, 2012 - 12:39 pm: |
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Apply a soldering iron to the screw head. Many times the heat will help the screw to release. |
Agfaclack
Tinkerer
Username: Agfaclack
Post Number: 2
Registered: 09-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 07, 2012 - 02:32 pm: |
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Thanks,
Good ideas - will try them. I have some extra screwdrivers to try the heat-tap-fit process with. Soldering iron sounds better than what I was doing.
Pete |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 57
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 08, 2012 - 10:08 am: |
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HOLD IT.
I am afraid you misunderstood me. I had narrated a process I used to make my screwdriver fit better on screws. I didnt say I hammer red hot screw driver tip in to screw which is on the camera.
While positioonbing sctew driver on the camera screw and tapping with hammer is also a method used often. But her you dont heat the head. The blows generate vibrations which will loosen screw a bit. |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 306
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 10, 2012 - 07:09 pm: |
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ahem.. heating the screw driver will anneal the metal n soften it to a point that will just strip on any screw that is a bit tough to move.
OTOH... Heating the screw head using a soldering iron is a good method as it will soften any lock tite or varnish sometimes used on certain screws.
Best thing is to have a good set of drivers to begin with. If they don't fit properly, filing the tip a bit so it seats better will work just fine.. Again this problem is typical of cheap sets, not typical of a better drivers with hardened points.
Oh... are you using the proper size driver for the screw you are removing? 0 or 00 or 000? Makes a big difference.
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Agfaclack
Tinkerer
Username: Agfaclack
Post Number: 3
Registered: 09-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 14, 2012 - 04:07 pm: |
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ThePurush,
I did understand you the first time - not on the camera, and was thinking you must need to dunk the new screwdriver-tip in cold water to re-harden metal.
I tried heating with a soldering iron, then thought it might be better to heat around the screw than right on it, so the hole would expand. I didn't succeed either way.
But one of the "solvents" I soaked the shutter in, probably contained some acid - the screws are now looking corroded, and the shutter acts like it. Well - I'm finding out what not to do.
Feel free to tell me which screwdrivers to get; I don't know anything about the sizing Paul_Ron mentioned.
Also, do repair-guys use something like an engineer's circle-stencil on screws, as a guard against scratching the rest of the camera? |
Scott
Tinkerer
Username: Scott
Post Number: 187
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 14, 2012 - 05:06 pm: |
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You'll get much better results with a set of good quality screwdrivers, but that will cost you $15-$20 at the very least. Wiha is pretty good quality. Also, fatter handles let you put more steady torque on a screw.
Check the shops where professional electricians and mechanics buy tools. The bigger hobby shops (like for model-train nuts) usually have good precision tools.
One way to apply a little more power is to wrap something made of tacky rubber (like a rubber glove, strip of inner tube, etc.) very tightly around the handle and secure it with a fat rubber band. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 58
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 15, 2012 - 06:16 am: |
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Agfaclack
Think before u invest on expensive screwdrivers. They are no good, but do they fit yr screws better?
Yrs if one off problem. I have uploaded a pic of my screw driver here
http://www.keepandshare.com/userpics/p/o/r/u/s/2012-10/ss/p1010129-19579322.jpg? ts=1350302886
The one on left is a similar the one I had before modification, On right is my modification. I modified the tip, cut off the shank then inserted in to a plastic handle for a better grip. The plastic handle is nothing but a handle of a razor shaver.
The modification proces consisted of using a good screw as mold, heating my old screw driver tip to red hot and then putting same in to screw and hitting with a hammer. It shd take the shape of the screw in abt 2 attempts. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 59
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 15, 2012 - 06:38 am: |
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I am sorry ther have been some typographical errors in the above.
quote
Think before u invest on expensive screwdrivers. They are no good, but do they fit yr screws better?
unquote
read this as
Think before u invest on expensive screwdrivers. They ARE good, but do they fit your screws better? |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 404
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 15, 2012 - 08:01 pm: |
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I have a small pair of pump (also known as Slip-Joint) pliers that I use to apply enough torque to loosen stubborn screws. Just put the driver in the screw slot, grab the driver handle with the pliers, give it a twist, and you're in like Flynn.
PF |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 307
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 17, 2012 - 06:39 am: |
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Another trick to undoing tight screws when they just become plain old impossable.. but not stripped yet, is using a flat tight fitting sharp screwdriver in the crosspoint slots.
When all else fails it;s time to drill it out n chase the hole with a tap.
Those screwdrivers in your pics are the junk ones we avoid like the plague.. that is why you are having these problems. They aren't meant to do this kind of work.
Some other tricks to stuborn screws besides heating em is to freeze it. That makes the loc tite or varnish brittle.
Whia, as mentioned, is a good brand of driver used by many repairmen. Sold in a small assorted kit for about $25 from MicroTools.. look em up online in the tool section of the catalog.
Your most popular size crosspoint is the 00 and 000. I buy spares of those n never ever heat em.
Doing a cold water dunk after heating a driver is worthless on low carbon steel. Either it doesn't harden or becomes too brittle and the driver tip crumbles as you slip in a stripped screw head.
The hardness has to be readjusted by baking the steel at a low temp after quenching to bring it back to a softer hardness but still hard enough not to break when stressed. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 60
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 19, 2012 - 07:18 am: |
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Well I am using my screwdriver for the last 10 years and it it sht one comes to my rescue wne ever i come across a stubborn screw. I too had gone through an ordeal, being unabale to open one screw in the bottom of Mamiya camera. I had almost lost all hopes. Then I tried my method and I never had a problem like again being stuck again.
As I said expensive screw drivers are definitely are good in every respect but what we need here is one that perfectly fits in the screw slot. When it does so you wdnt feel any play as you turn it either direction. |
Agfaclack
Tinkerer
Username: Agfaclack
Post Number: 4
Registered: 09-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 20, 2012 - 02:20 am: |
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Purush, I'm definitely going to try that one - I never did like the way most screwdrivers are tapered like a wedge. I'm not having that much trouble with the fit, though. It's like the screw-heads might break off. The rubber inner-tube roll idea is a good one - I have lots of that. I have used vise-grips and so forth before - works, or twists the screwdriver. I may just buy a better shutter/lens combo anyway. |
Paul_ron
Tinkerer
Username: Paul_ron
Post Number: 309
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 22, 2012 - 03:02 pm: |
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There is a difference between what we once called a crosspoint screw, generic AKA philips and an actual philips. But over the years the old term has washed away. So there may stil be a difference but I really don't know for sure.
But... I have noticed there are differences in my old drivers as compared to the newer ones as far as fit. I have to taylor my newer drivers a bit by flattening the tip slightly to seat properly. Also if you use the proper size driver that fits your screw.. it makes a hell of a difference.
Those silver Radio Shack swivel head drivers are real crap and have ruined more screws.
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