1 of 1- Fleetwing
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Offline - From: Hartford, CT USA
- Registered: 30-6-2015
- Posts: 1,011
Taps
No, not the military fanfare for the fallen, but the tool for re-boring threads. Seems that in trying to reattach a panel on a new to me SG1 that's in need of work, I was unable to reinsert a machine screw for the rear covering. It came out hard, but simply would not go back in, which I found very surprising. Of course, the screw head is semi-mangled, but still has a usable slot. Where does one find a set of metric taps? I think the diameter of this screw is only about 2mm max,. pitch unknown but no doubt a standard metric pitch. My guess is that the screw went in wrong at the factory and I was the first one to remove it. (The good news is that I was able to fix the margin release -- a reluctant spring -- which was why I was taking the back off in the first place.)
Maybe someone knows the precise diameter and pitch for this screw -- it's one of the two smaller ones on the ends of the carriage rear cover, not the screws in the middle of the back.)
Much obliged for any help.
- Uwe
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- From: Toronto, Canada
- Registered: 12-3-2013
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Re: Taps
Fleetwing wrote:
My guess is that the screw went in wrong at the factory and I was the first one to remove it.
It's highly unlikely that you were the first person to have ever removed that particular cover on a machine that is over fifty years old. My money would be on the screw having been cross-threaded by some shadetree mechanic rather than someone on the Olympia assembly line.
If you don't own a metric tap and die set, but you own an imperial one, why not just replace the one screw with an appropriate size machine screw and tap the damaged hole to fit it? If you want to keep the hardware as original as possible, I'm sure thee's a specialty fastener store in your area that carries metric fittings. Just take one of the other cover screws there and match it with a replacement they have, and at that point you'll know the size and pitch that you need to tap. The fastener stores in my area sell taps too, but metric taps are readily available, online if need be.
The pronoun I has always been capitalized in the English language for more than 700 years.
- Fleetwing
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- From: Hartford, CT USA
- Registered: 30-6-2015
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Re: Taps
Thanks, Uwe. You may be right, though it's hard to believe a shade tree mechanic would have been able to reinstall the screw without marring it. The rust on the machine might be contributing to this difficulty.
I figure I'll try to find a local place that can at least tell me the screw size. I'd hate to have to buy more equipment than I need to retap this thread (and no, I don't have any taps or dies, whether metric or SAE). What would be great would be to find a machine shop that'll just do it for me -- not wild about lugging the SG, even just the carriage, into a shop, though. It appears to be a very small screw, like 1.4mm. The pitch I'm clueless about, though.
Kills me that this was the literally final step in buttoning down the machine after getting the margin release working! Oh well.
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Thread Starter- Uwe
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- From: Toronto, Canada
- Registered: 12-3-2013
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Re: Taps
...it's hard to believe a shade tree mechanic would have been able to reinstall the screw without marring it.
I'm confused. In your first post you stated that the "screw head is semi mangled." Was it you who damaged the screw head, or was it like that?
It is possible in some cases to re-tap a hole using a few new screws as disposable taps. I've done it often enough, you just have to be very meticulous about what you're doing, and just slowly work the screw in and out a little bit more each time.
The pronoun I has always been capitalized in the English language for more than 700 years.
