Grub screw help for RE Auto Topcor 58mm 1.4

Macca · Joined: 20 Mar 2012 Posts: 248 Location: Glasgow, Scotland.

Hi, I managed to give my Topcor a basic clean and lube. A minor mishap with the last grub screw, the end split. I got it out ok but wondered if anyone knew the size of the screw and replacement screw sellers in UK/EU?

Thanks

p.s. it`s this one. I have put a jewellers screw in just now to let me check everything is working but can only focus to about 2.5 meters as its not flush like the grub.....

themoleman342 · Expire: 2013-01-24

I have yet to find a supplier of grub/set screws for lenses. I know when I contacted micro-tools a couple of years ago they had nothing even remotely close. Haven't checked there in a while though.

I can only get them from donor lenses.

Macca · Joined: 20 Mar 2012 Posts: 248 Location: Glasgow, Scotland.

Thanks, the jeweller had a look. He said he could try to grind me one if I can`t find a replacement, not sure about that approach as it needs to be removable.

Looking for dead Topcors might be problematic, even the dead ones are pricey! Shocked

guardian · Joined: 18 Mar 2009 Posts: 1747

Very difficult situation. I have no answers.

If you have a screw (from a donor lens or whatever) that's close, the key could be taps. A set of taps might be easier to buy than the screws themselves. You would re-tap the (already threaded) hole to fit your donor screw. If you could go a tiny bit oversize on the donor it would give you the hope of a better outcome. Course to facilitate that you might need also to buy drills, along with the taps.

Thing is, speaking in general, when threads (either male or female) become boogered, sometimes a fresh start can be the way to go if circumstances permit, i.e., if there is room.

Macca · Joined: 20 Mar 2012 Posts: 248 Location: Glasgow, Scotland.

Guardian, thanks, the jewellers screw I have in at the moment is a tight fit and I didn`t overscrew it in case I ruined internal threads ( may already be damaged , who knows?).

I found this Japan based webpage which manufactures setscrews and exports around the world. No idea of costs yet but they provide free samples!

http://www.del-screw.com/category/1449618.html

I guess I need the accurate size of this screw, has anyone got a micrometer and an RE Auto Topcor 58mm 1.4??

I have the remnants of the screw, I may take a macro shot of it next to a ruler and email it to them if all else fails...

themoleman342 · Expire: 2013-01-24

You don't need one directly from a topcor. They're definitely not a special size. It's probably the 1mm or 1.2mm diameter ones.

John Shriver · Joined: 24 Dec 2009 Posts: 189

It definitely is a metric screw. You don't need a set-screw. You can take an ordinary metric screw, file the end to a point, and cut off the head. You can cut a slot with a fine blade in a jeweler's saw.

Also, I think there's three of them, so long as it's not the longer one, you don't really need it. Just keeps the filter ring in place.