8mm Forum: Sankyo 1000 Jitters

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Posted by Janice Glesser (Member # 2758) on November 19, 2011, 06:36 PM:

Now that I have my picture quality greatly improved after removing the glass heat shield on my Sankyo 1000 http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=006637 I need to see if there's a way to stop or at least minimize on the frame jumping/jittering. Initially I thought it was just the films themselves...but when I run the film in reverse....guess what?...no jitters. Any advise on what is causing this?.. Is it fixable?...Something I can do?

Posted by frank arnstein (Member # 330) on November 19, 2011, 11:52 PM:

Hi Janice

I didn't need to think too long about this one because it is also quite common on old Sankyos.

This is a completely sprocketless projector, reliant on the claw to move film through the projector. However it still needs 2 loops to work properly or else the film will jitter whenever there is sudden change of tension in the film from the take up reel. That slight tug will be felt all the way back to the claw and aperture, where the picture will jump when the tension is felt. The pressure plate tension is not enough to insulate the film from this jerking or jittering.
So the cause must be eliminated or the symptom will remain.

The lower loop former is the source of the problem. I have tried without luck to post a pic with the tin cover removed to show the internal parts at work. Will send it to Pat to post here for me.

The loop former is actually driven by a large round ring of rubber. This ring is compressed by tension in the film and it will respond by collapsing smoothly. If the tension changes again, it will spring back to its original shape and that pushes out the lower loop former to where it was parked before.
The problem lies in the rubber ring loosing its springiness over time and staying partially collapsed. This means its oval instead of round. This effects the amount of rebound that is available and the smooth dampening effect of the loop former is reduced to the point where the film jitters and it is felt at the aperture as a jitter.

To restore the correct function, carefully unglue the rubber from its attatched point and then turn it around 90 degrees till it resumes pushing the plunger back out easily and smoothly. If it works ok then reglue it in position. Test it with your finger for smooth rebound operation, then replace the tin cover and test it again.
If still ok, try projecting a film and see if the jitter is gone. Observe the loop former in operation when it is projecting and make sure it isn't sticking at all. It may need a tiny spray of lubricant to the sliding plastic parts.

So we will see how you go on this 2nd repair to your Sankyo. So far you have done very good.
Let us all know the result and hope it will be as good as lst time.

dogtor frankarnstein

Posted by Janice Glesser (Member # 2758) on November 20, 2011, 01:24 AM:

Well Frank, you have definitely honed in on this problem too [Smile]

I'm guessing by now you have figured out I'm a "picture" person...so I will need a pic to go along with what you have described. This seems a little more complicated than the glass fix ... and I'm going to take a wild guess that this isn't "the claw" you are talking about :-)

Posted by Pasquale DAlessio (Member # 2052) on November 20, 2011, 03:11 AM:

Janice

This ones for you! I'M POSTING THIS FOR DOGTOR FRANK.

IGOR

YOU GO GIRL!

Posted by Janice Glesser (Member # 2758) on November 20, 2011, 12:00 PM:

Thank you Pat for helping out. Frank...I'll have to study this view...at first glance I'm not sure what I'm looking at :-( I'm putting this fix on hold until after the 29th. I'm heading down to LA to visit one of my sons and celebrate Turkey Day :-)...Stand By.

Posted by Janice Glesser (Member # 2758) on November 20, 2011, 03:00 PM:

One more thing Dogtor Frank before I go...I figured out what was shown in your pic [Smile]

I removed the tin plate. I just wanted to clarify if the arrow is pointing to the correct part in question that needs to be unglued?

At least I'll know where to start when I get back.

Posted by frank arnstein (Member # 330) on November 21, 2011, 02:57 AM:

Thats correct Janice.
All the action happens under the tin plate that you took off.

Next gently peel the rubber off from where its glued.
When its off you will see how its gone oval from being in the same position for 45 years.
When refitting, make sure its position provides maximum push to the peg, then reglue. Check the parts slide freely back and forth when the cover is back on. It may need a spray lube if its sticky at all.

Then test it out to see if the jitter has gone in forward projection.

We will wait till you report back with result.

dogtor frankarnstein [Wink]

P.S. How do you make those nice red pointer arrows on your pics?

Posted by Janice Glesser (Member # 2758) on December 08, 2011, 11:50 AM:

Frank, I haven't forgotten about this project, but with the holidays upon us...I'm just putting it on hold. I did pick up a Sankyo 2000H which has less of a jitter problem and I was able to complete some transfers for a video montage project I was working on. I still want to get the 1000 jitters under control though. I'm thinking if that rubber ring needs to be replaced are there any DIY alternatives you can think of?

BTW...In the photo with the arrow, I used Photoshop CS5. It's a feature built-in the software.

Posted by frank arnstein (Member # 330) on December 09, 2011, 06:38 AM:

Janice,
Unless you have bad luck removing the rubber ring it should be able to be re-used Ok. I cant think of anything else to use as a complete replacement so be careful peeling it off the glue. They can tear.
The 2000h you have bought is a younger and better machine. It still has the same loop forming device but the rubber ring would be more springy and so work better.
good luck with them...

dogtor
[Razz]

Posted by Janice Glesser (Member # 2758) on February 22, 2012, 01:52 PM:

I wanted to update this thread. I was able to rotate the rubber ring and re-glue it back....If anyone else tries this... DO NOT use Super Glue [Frown]

Airplane glue...or even Rubber Cement is good enough.

A couple months later I bought an old junker machine of the same model and replaced the entire lower film guide [Smile]

Posted by Janice Glesser (Member # 2758) on January 05, 2013, 12:39 PM:

UPDATE...I have recently found an simpler solution to reducing the jitters on this projector. It doesn't require removing...turning...and regluing the rubber bumper ring.

I had some Scrub IT sponges I bought from the Dollar Tree. The sponge is very soft and pliable. I cut a small section out of the sponge...slightly bigger than the inside opening of the rubber ring. I just inserted it inside the ring (no glue)...replaced the shield and the lower plastic guide. This fix very much improved the jitters.

Posted by Keith Heydon (Member # 3138) on January 05, 2013, 02:11 PM:

This is my first post on this forum ....so I hope it ends up just below Janices' [Smile]

I have 2 Sankyo Dualux 1000's and I've been following her efforts to get that model of projector into top shape.

This latest post to resolve the "jitter" issue could be just the thing for one of my projectors.

I love the DIY approach ...and, I always appreciate the "cost savings" of materials sourced from a dollar store! [Wink]

I'll post back here when I try this with mine.

Cheers,
Keith

Posted by Janice Glesser (Member # 2758) on January 05, 2013, 06:55 PM:

Go for it Keith and welcome to the forum. There's a wealth of knowledge and expertise here and the members are very generous. Folks here have been extremely patient and helpful educating and supporting me with my obsession to fix my projectors [Smile]

The Sankyo's are very good machines and worth the time in getting them to run as good as possible.

Posted by Steve Hartwell (Member # 4101) on December 27, 2016, 07:25 PM:

I tried the sponge inside the rubber ring fix but it didn't help. I watched the loop former perform during the film playback and the loop former assembly looked to me to be doing it's job, rapidly moving to compensate for an ever changing tension on the film. It never stuck in compressed position.

My film still jitters.

Could it be caused by some other problem, maybe somehow I screwed up the claw while cleaning the gate with a felt brush ? Or maybe a slipping belt, or speed governor for the takeup reel, or,

Posted by Janice Glesser (Member # 2758) on December 27, 2016, 08:23 PM:

Hi Steve...If all the things you have tried did not help the jitters...I found this adjustment to the take-up spindle rod to be very helpful (this shows how to adjust both the 2000H and the 1000 models.)

http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=009280

If film jams and won't thread try adjusting the claw. It's not difficult. Here is a thread describing how to do it:

http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=009946

Posted by Steve Hartwell (Member # 4101) on December 27, 2016, 11:42 PM:

Thank you Janice, I shall try your suggestions.

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