Keystone projector take-up reel speed problem

[Herb Roosa]

I have a Keystone K-108 projector (S/N K5709). It functions well, with one exception: The take-up reel/sprocket seems to run faster than the in-feed, which causes the picture to flutter as soon as the out-feed loop is used up. I'm wondering if there is some kind of adjustment that can be made?

I feel that the sprockets were likely gear-driven, and should run at the same speed. I've removed the covers for the arms holding the two reels, and observed that they are gear-driven. All appear to function properly. Also, the projector has been lubricated recently at all points.

If I allow the film to simply spill onto the floor when viewing, (do not use the take-up reel), then both loops of film (before and after the lens) will remain constant, and the film does not "flutter".

This is risky when playing a large size reel. I've experimented with gently dragging a finger on the edge of the take-up reel, to slow it somewhat. This seems to help, but doesn't seem like a wise solution.
I've been unable to find any documentation for this projector on the internet.
Any suggestions would be welcome.

[Nate Lockhart]

Got any pictures of the inside that you could upload? That might help conjure some theories...

[Herb Roosa]

Nate:
Thanks for your reply. The only disassembly I've done is to look behind the covers on the reel arms. Without a service/parts manual, I'm reluctant to just wing it. As stated before, when running without using the take-up reel, all is well and both loops remain constant. When using the reel, the lower loop will diminish within seconds.

[Nate Lockhart]

This model has variable speed control, right? I wonder if the problem is electrical rather than mechanical?

[Nantawat Kittiwarakul]

Nate:
As stated before, when running without using the take-up reel, all is well and both loops remain constant. When using the reel, the lower loop will diminish within seconds.

In essence, the film slipped off the lower sprocket hence the loss of lower loop. That means either excessive take-up force, or loose sprocket shoe, or both.

Try running the projector idle with empty takeup reel. Let's see if you can stop the reel from spinning with moderate resistance. If the torque seems uncomfortably high, or the whole projector "stalls" from that, this would indicate some sort of sitcky slip-clutch mechanism somewhere inside.

[Herb Roosa]

Thanks gentlemen.

In response to Nate, yes it does have a variable speed control. It functions fine, but varying the speed does not affect the problem.

Responding to Nantawat, I observed that the film is actually "jumping teeth on the lower sprocket. The keeper tab (shoe?) is spring-loaded, and is bouncing as the film is pulled forward and "jumping teeth". If I hold the tab down with my finger, I can prevent that from happening, but that's not practical...
As to your suggestion: I can indeed stop the take-up reel with finger pressure (moderate). The projector motor and sprockets do slow down noticeably, and sound strained.
You mention a slip-clutch mechanism. Do you suppose this is adjustable (or serviceable)?
Again, I have no manual. I'm wondering if anyone out there has one?

[Nantawat Kittiwarakul]

It would be considerd "normal" if the projector slows down somewhat 5-10% under the load as I previously mentioned. This kind of projector (usually) does not have any kind of speed regulation system to keep it steady like the sound projector, so this is to be expected.

But considerable speed drop under normal load means something out of whack for sure.

Haven't owned that one or ever seen it in person, but that slip-clutch mechanism would be right behind that metal plate covering that reel drive gear train, or even deeper inside in the body. Only way to find out is to further disassemble it.

Since you mentioned the film did jump the sprocket teeth when running, so the sprocket shoe didn't do its job well.

Congrats, seems like you're lucky to have both problems.

[Janice Glesser]

Hi Herb... I have the K-109. My Mom bought it in 1954. It too continually loses the bottom loop. Admittedly I haven't spent any time troubleshooting the cause. These Keystones are built like tanks and not always intuitive to take apart. I hadn't considered the take-up real being an issue... but this thread has me interested in checking it out. Hopefully someone will pop in that is familiar with this projector and the problem.

[Herb Roosa]

Thank you Nantawat. I've been tempted to dig deeper into the internals, but would love to hear from someone with experience first! (after all, the projector does basically work okay... afterwards, you never know!).

Thank you, too, Janice. Good to know that I'm not the only one with this problem! I've seen in your earlier posts that you have a manual for your K-109. Does it show any details at all regarding parts breakdown, service, etc.? I'm guessing not... My projector has been in the family forever; as a young boy (50+ years ago!) I was the designated movie operator, but I can't really say whether it did this then. If you think your manual would be of any help, I'd love to see it. Our original manual, along with the splicer/viewer, disappeared with time.
Thanks again!

[Douglas Meltzer]

Herb,

I've sent you a scan of the Keystone 109D manual.

Doug