Film-Tech Forum ARCHIVE: help needed in identifying a RCA100 lens mount

This is topic help needed in identifying a RCA100 lens mount in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Luciano Brigite (Member # 1104) on 08-09-2005, 08:07 PM:

Hello,
I recently got a pair of RCA 100 projectors ( finally!) and one of the heads is missing the lens mount. acording to the manual available here on Ft, there is 2 kinds of lens mount, one called standard (2 25/32") and a larger one (4").
I measured the diameter of where the lens bushing goes and it's not any of the sizes mentioned in the manual. what I got was 3 5/8" diameter, measured at the front of the lens mount.
I'm looking for this part to replace the missing one and need help in finding out wich one I have since the measurements doesn't match.
I attached a picture of the other head I have with it's lens mount assy for help..
Thanks..
Luciano

Posted by Mark Gulbrandsen (Member # 72) on 08-09-2005, 08:44 PM:

Luciano,
Thats a standard lens mount BX-100. They also made a 4" mount BX-100 to accomodate the heavier 4" lenses. These BX-100's were more common in drive ins. Unfortunately keeping a BX-100 running today is about impossible unless yours happens to have an original Brenkert cone shaped fibre shutter deive gear. The only other gears available short of having them made were made by Wolk years ago out of a fibre(phenolic actually)that had too corse of weave to it. These Wolk gears only last a few weeks at best. The Wolk BX-40/80 gear was not much better. Its an old basically unservicable machine that would make a good display in a theatre lobby.....

Mark

Mark

Posted by Luciano Brigite (Member # 1104) on 08-10-2005, 07:20 PM:

Thanks for the info Mark;
I still didn't have the chance to give a good look inside them since I took the machines from a.. porn theatre (sigh) 2 weeks ago. they were abandoned in the booht when the theatre closed one of hte screens years ago. hte only thing I know about the shutters in them is that the dual blade was removed and replaced by a single blade shutter.hte only mechanical issue I noticed with them for now was a broken gearbox in one of the soundheads.
Any idea where I'd find the lens mount for it? Sent a few emails already ,no reply to some and waiting a message from someone who replied to my post on the wanted forum [Smile]

And i've been pondering going back to the theatre to remove the original bases I left there hmm.. dunno if it's a good thing or not... [uhoh]

Posted by Jeff Stricker (Member # 224) on 08-11-2005, 07:06 AM:

Luciano, I have three Brenkerts ( two BX-40 single shutter and one BX-60, also single shutter) They have the original shutter shaft drive gears and have not given me any problems (of course they are in home theater, not everyday service). Mark cautioned me about the drive gear problems when I first got these five years ago, but so far all has been well. They are heavy duty machines!

Don't know where you can find a lens mount, but I'll bet there are some cadavers out there that can be stripped for parts. Keep looking.

Posted by Mark Gulbrandsen (Member # 72) on 08-12-2005, 01:15 AM:

If you can find the original BRenkert drive gears all will run just fine. The phenolic that Wolk used on his Brenkert 100 gears was just of very poor quality. The BX-60 is overall a much different but better and more efficient design.

Mark

Posted by Luciano Brigite (Member # 1104) on 08-12-2005, 06:45 PM:

The only thing I know for now about my BX100 is that hte shutters were modified, the dual blade was taken off and replaced by a single blade. I didn't pay much attention to the drive gears when I opened them for the first time, I think they're all metal in mine. If things goes as planned tomorrow I'll give them a good "shower" and inspect everything.
The lens mount is the only part that is worrying me more,ohter htan it I'll also need sprockets and a few other things ( made a post on hte wanted forum about the parts)
I'm keeping an eye on a pair of BX60, one lonely BX60 head and not sure yet of model , one BX80 head