8mm Forum: Help - Keystone Moviegraph D-752 sprocket problem

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Posted by Gert Bruhn (Member # 6994) on June 06, 2019, 10:25 PM:

Hi!
I recently acquired a Moviegraph D-752 projector that turned out to be non-functional when tested with a film in it. When I switched it on, the lamp lit up but the motor wouldn't turn. It started humming, a sure sign that it was up against some immovable obstacle. I immediately switched it off to avoid serious damage. I took the belt off the sprocket pulley and rotated it by hand, but the sprockets could be moved only a quarter turn in either direction. Something solid was blocking their movement. But what and why? Could someone please explain and offer a solution? Thanks a lot!
Gert

Posted by Nantawat Kittiwarakul (Member # 6050) on June 13, 2019, 08:02 PM:

Totally unfamiliar with that machine,but a picture (or better a bunch of it) would probably help. [Smile]

Posted by Maurice Leakey (Member # 916) on June 14, 2019, 04:37 AM:

Seems to be extremely old!
It's quite possible that the mechanism has seized due to many years in storage.
I suggest that you open up and try to ascertain the problem. It will need be re-lubricated but if it has a gearbox this could be quite a problem.
Good luck.
https://www.etsy.com/uk/listing/695133679/antique-keystone-moviegraph-16mm-film?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=keystone+moviegraph&r ef=sr_gallery-1-1&referring_page_type=market&pro=1

Posted by Gert Bruhn (Member # 6994) on June 18, 2019, 09:13 AM:

Hi! Thank you very much for your input gentlemen. I will try once again to locate the obstruction that prevents the sprockets from turning. I don't think they are frozen because of hardened lubrication, otherwise they wouldn't turn at all. They can be rotated about one turn in either direction before they are blocked. I have a hunch it's the control mechanism of the in-and-out claw which engages the film as it goes through the filmgate that is the culprit here. I have wiggled it back and forth, but alas the sprockets still won't move freely 360 degrees. Any other ideas?
Gert

Posted by Nantawat Kittiwarakul (Member # 6050) on June 18, 2019, 10:02 PM:

Gee,that's a REALLY OLD ones! [Eek!]

But since this seems to be in the "toy projector" catergory,the mechanism shouldn't be that complicated. If it's me l would probably do the total disassembly/cleanup/lubrication,even if it is still running anyway. [Wink]

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