Film-Tech Forum ARCHIVE: Shaky Picture with a motiograph

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Posted by Christopher Lani (Member # 7952) on 11-05-2013, 03:37 PM:

Hello You all! I am really in a bind. I am still running a Motiograph AA 35mm projector. It has been running fine but all of a sudden the image is beginning to shake and shimmy. I replaced the intermittent gear assembly and the shoe that holds the film. I am still getting a shaky image with a copy of "FreeBirds" Is there anything else I can adjust or try to stabilize the image? That you so much!

Posted by Mark Gulbrandsen (Member # 72) on 11-05-2013, 04:24 PM:

It may be that the sprocket teeth are hooked badly. No amount of extra gate tension and so on can fix that. Only a new sprocket will and they are NLA or you have to salvage one off another projector. Examine the teeth carefully to see if the are undercut on the pull side of the teeth. I know where there are a couple AA's sitting if you get in a bind.

Second guess would be too little gate tension from worn parts. Try holding back on the film at the top of the gate to see if the steadiness is improved.

Last guess would be a loose lens element. Especially if you have a certain era of Schneider lens. They did not locktite the retaining ring in place and the front or the rear element can come loose just enough to cause a shake in the image. I actually had this happen at a number of locations.

Hope this helps...

Mark

Posted by Christopher Lani (Member # 7952) on 11-05-2013, 04:45 PM:

Thanks Mark, Great places to start. I will keep you informed. This old machine had played magnificently up until know.

Posted by Mark Gulbrandsen (Member # 72) on 11-05-2013, 06:55 PM:

Theya re still excellent projectors if you have the parts stash to keep em running...

Posted by Donald Brown (Member # 5427) on 11-05-2013, 08:42 PM:

Christopher:
Check the lateral guide rollers above and below the aperture. While they were prone to bind from dirt that would collect around their inner retaining points, I have also found situations where roller alignment was thrown off when the set and lock screws loosened. The on screen image lost its stability as a result.
I still have a lot of new and used Motiograph parts if you need any.

Don Brown

Posted by Christopher Lani (Member # 7952) on 11-06-2013, 12:25 AM:

Thanks Don! I am gonna tear into it tomorrow and I will let you know!

Posted by Steve Matz (Member # 1890) on 11-06-2013, 10:36 AM:

sorry this isn't related to your problem...The last drive-in theater here in Billings,mt called the Motor-vu used motiograph AAA projectors with strong mighty 90 lamps.The projectionist was old school licensed electrician and he really was knowledgble about projectors.He and a lot of oldtimer projectioists from the 40's & early 50's thought Motiograph was the rolls Royce of 35mm projectors.He's been dead for years but you could listen to this guy for hours talking about running film in the 30's 40's 50's Motiograph and a lot of other Chicago based Mfgers like Devry all went under around 53-54....TV really killed the theatre business then. if no new theaters are being built and your not selling new equipment

Posted by Christopher Lani (Member # 7952) on 11-07-2013, 02:19 PM:

IS it possible that I just got a bad new print? Has this happened to anyone?

Posted by Jack Theakston (Member # 4484) on 11-07-2013, 02:37 PM:

That's always a possibility. Have you tried running anything else (preferably something you know) to get a comparison?

Posted by Martin McCaffery (Member # 37) on 11-07-2013, 02:43 PM:

quote: Christopher Lani
IS it possible that I just got a bad new print? Has this happened to anyone?

Absolutely. Take out the aperture plate and run the film (with the curtains wide open if that's an option). If the sprocket holes are steady but the picture is jumpy, you have a badly printed film.
Yes, it happens much more often than it should.

Posted by Donald Brown (Member # 5427) on 11-07-2013, 04:48 PM:

Christopher:
That occurred to me with your original posting.
It seemed unlikely that the picture would become unsteady abruptly. There would likely have been a noticeable change in the on screen image that gradually worsened.
Over the course of the 2013 summer season, there was a noticeable change in the overall quality of 35mm prints. It appeared as if an economy in production had been achieved as overall demand for prints declined.
Don Brown

Posted by Christopher Lani (Member # 7952) on 11-07-2013, 05:27 PM:

Does anybody know how to actually get the intermittent cam out of the assembly on the motiograph aa?

Posted by Martin McCaffery (Member # 37) on 11-07-2013, 09:11 PM:

There's a AA manual in the Warehouse that has step by step instructions.
It's been more than 20 years since I removed one, so can't help.

Posted by Donald Brown (Member # 5427) on 11-08-2013, 09:41 PM:

Christopher:
The Motiograph intermittent is rather simple to repair if you have the parts.
To disassemble the cam, start by removing the pin in the drive gear. Do this while the assembly is still intact to avoid putting pressure on the cam shaft while it is unsupported. Remove the inner collar from the threaded end of the cam shaft, and then separate the intermittent casting by removing the four screws that couple the two halves of the case.
As long as there are are no irregularities on the cam shaft, it should slide out of the brass cam bearing with little difficulty. This is where I have encountered a bit of resistance though as the outboard ball bearing on the cam shaft will frequently be frozen to the shaft. (This might not be the situation with yours if its from an indoor theatre that's been in continuous operation.)
If the bearing is frozen to the shaft, bring the assembly to a machine shop and have it pressed off.
The reassembly should go smoothly by reversing the above, not forgetting to replace the cover gasket and realigning the cam pin with the star.
I still have a number of new/rebuilt intermittents if you need one.
Good luck,
Don Brown

Posted by Christopher Lani (Member # 7952) on 11-13-2013, 03:26 AM:

Well, it ended up being a combination of the intermittent outer bearing being jammed which caused excessive wear on the two drive gears coming up from the RCA soundhead! Replaced all three and presto! A stable image! Now the picture is pulling up a little out of frame while playing. It only drifts up so much but it is still annoying. I notice that the shutter adjustment knob has to be turned all the way down and there is a faint whirring noise like something is not quite right. I am going to pull the Intermittent and advance the gears a little so that the adjustment is more to the middle of the shutter adjustment range. I think it might be torquing the intermittent a little and pulling the frame up. Is there a way to tighten the whole framing mechanism? Thanks for all the help from everyone here and the Claco tech in Salt Lake who hooked me up some parts in Idaho. Thanks for the offer Don, I may still hit you up for some parts!

Posted by Donald Brown (Member # 5427) on 11-13-2013, 03:51 PM:

Christopher:
The first area to check to adjust the vertical tension is with the spring tension on the shaft that holds the framing knob. There is a spring attached to the framing shaft inside the shutter opening on the rear of the head. To adjust the tension, remove the operating side framing knob, then push the shaft toward the gear side of the head. When the gear disengages from the rack on the shifting frame assembly, recover the tension by rotating the shaft. There are specific instructions in the manual on this site that give recommendations to achieve the correct tension as well as for re-engaging the gear with the rack.
There is also method to adjust the tension of the v-rails on the shifting frame with the adjustment screws on the right hand rail, but it would be best to start by checking the spring tension first.
Don Brown

Posted by Jim Cassedy (Member # 4115) on 11-13-2013, 06:10 PM:

quote: Steve Matz
He and a lot of oldtimer projectioists from the 40's & early 50's
thought Motiograph was the rolls Royce of 35mm projectors

Same experience here. A lot of the 'old timers' who I worked with in the NY union
back in the 1970's swore by by the "AA" Motiograph machines.

There were quite a few of them in the booths of the old "Prudential" theater
chain (later "AIT") on Long Island back then. The standard practice in many
booths was lube the gears with nothing more than common vaseline.
It seemed to work OK. (And it alleviated my apprehension when I first got into
'the business' as to why every booth seemed to have large jars of vaseline around!)

Posted by Christopher Lani (Member # 7952) on 11-13-2013, 10:12 PM:

Would this be the answer if this only happens once the projector warmed up? I came back in during the movie and it was half way up the screen! I have my hand on the framing knob as I write this!

Posted by Christopher Lani (Member # 7952) on 11-14-2013, 02:16 AM:

Okay, I made it through and am going to adjust the spring tension in the morning. I see the descriptions of both procedures in the 2 manuals. The problem is I don't see corresponding illustrations for the second procedure. Kind of confusing. I will let you know how it goes in the morning. Adjusted the shutter timing and other than the creeping, the machine is running well. Thanks again Donald!

Posted by Christopher Lani (Member # 7952) on 11-14-2013, 12:47 PM:

I found the illustrations at the begining of the file! Duh, Thanks!

Posted by Christopher Lani (Member # 7952) on 11-14-2013, 02:19 PM:

That worked line a charm Donald! Thanks again. I owe you one and thanks also goes to Film-Tech for having such an awesome site!

Posted by Stu Rasmussen (Member # 7970) on 12-09-2013, 12:43 AM:

I don't think it's necessary to remove the intermittent and rotate it to adjust the shutter timing - at least it isn't on the AAA and I think that part of the head is the same between the AA and AAA models. If that's not the case - ignore the rest of this post!

First, adjust the shutter timing knob to the middle of its range.

On the non-op side of the projector, locate the alignment hole in the casting that engages a hole in the shutter drum. Slide a 3/32" pin punch into that hole, push it gently toward the shutter and rotate the mechanism until the pin engages the shutter drum.

Next, loosen the Allen screw in the middle of the shutter gear that holds the shutter gear to the shutter shaft and pull back gently on the gear. This decouples the shutter drum from the gear train and allows the mechanism to turn freely while the shutter remains stationary.

Go around to the operator side of the projector and turn the mechanism in the forward direction until the intermittent sprocket just starts to turn. It may be easiest to put a finger on the intermittent sprocket and stop turning when you feel the motion of the sprocket. This is the 'sync' point to the (currently locked by the 3/32" pin punch) shutter drum position.

Go back to the non-op side and tighten the Allen screw in the shutter gear while being careful to not move the rest of the projector gear train. . Remove the 3/32" pin punch that is locking the shutter and you're pretty much in sync. Run a test film and fine adjust the shutter timing. Done!