Elmo GS-1200 maintenance

[Lee Hardcastle]

Hi! Thanks for having me on your forum.

I'm completely new to super 8 projecting. But I've jumped in and gotten an Elmo GS-1200.

I've successfully watched some movies on it and it's most excellent!

I have a question;
Does anyone have any advice or guidance on the upkeep on the the projector? Is there something I should be doing or checking from time to time to keep it in working order?

Thanks,
Lee

[Kevin Faulkner]

There are quite a few things to check such as checking the input guide isn't worn. This is the lower guide with the arrow on it where you insert the film. Also check the black swinging tensioner after the roundhead and the capstan. Feel along its surface where the film runs and make sure there are no flats. It's should be curved and smooth. Wear at these points will cause scratching. These machines seem to run better with regular use. Each time you fire the machine up put it into the record mode on both Chanels a few times. The machine can be in standstill while you do this but certainly no film loaded. This helps to keep the switch contacts clean.
General cleanliness is a godsend. Keep the soundheads, capstan and pressure rollers clean and make sure the gate is clean. A build up of magnetic oxide or film emulsion anywhere can also lead to scratching etc.
There are other places to check for wear but lets leave those for a later post.
Also check out the sticky thread in the 8mm Forum called Index of Technical Topics for more info on things to check and maintain on the GS1200.

[Lee Hardcastle]

Thank you, Kevin.
There's a lot more here to consider than I realised.
I need to make sense of a few of these name parts.

Is this black swinging tensioner? It looks a little worn on the edge.

[Kevin Faulkner]

Not that's not the part I'm referring to. That's part is for restoring the loop if the loop gets lost during projection due to a damaged sprocket etc. I will photograph the part I'm talking about tomorrow and post a pic fro you.

[Kevin Faulkner]

Lee, Here are a couple of pics of the part I was referring to. Check underneath that there are no flats worn into the plastic where the film runs. It should feel curved from front to back if that makes sense.

[Douglas Meltzer]

That's the part I'm hoping that Van Eck Services will put out a replacement version with a roller.

[Kevin Faulkner]

That would certainly be good if they did do that Doug. On my GS1200 Xenon and my HID converted std machine I have used rollers from the ST1200HD. It completely removes any wear that could happen at that point with the plastic part Elmo fitted.

[Graham Ritchie]

Hi Kev

I did the same thing using an old roller from a ST1200, works fine .

[Kevin Faulkner]

Nice job Graham 👍

[Steve Lee]

Can anyone please tell me what is the diameter of this roller, as I am now desperate to get my GS running again, after sending this part to Van Eck Services in order so it could be reproduced.
I regret this decision everyday, as I had no idea that two years later we would still be without this part. I would be truly grateful if anyone can help, as my GS1200 was a new old stock machine that I purchased about four years ago. I am afraid if it sits there any longer in a unusable state, problems are going to develop on it.

Steve

[Kevin Faulkner]

In theory Steve it should still work without but you might find that you get some wow on the sound. I can have a look in my bits box to see if I have one I can send you.

[Steve Lee]

Thank you Kevin. I have just found these rubber coated bearings online, and was thinking of placing two of them side by side as they are only 4mm wide.




To then 3d print a bracket that can hold a spindle, and also have a hook for the spring to attach too.
I will have ago at printing this tomorrow.

Steve

[Kevin Faulkner]

The Elmo ST1200 rollers are not a wide as the film. It runs down the centre of the film. They are about 6mm width.
I do have one of the original plastic parts which did have the worn flats but have been reshaped with a hot iron to regain the correct contour and remove the flats. Pics below and you're welcome to it if you want it. No charge as I won't use it again. PM me if interested. I take it you still have the screws and spring.

[Kevin Faulkner]

Just as a matter of interest Steve I measured the ST1200 Roller I'm using on my GS and the outside Diameter is 12mm and the width is 6.5mm. I would think that anything similar would work fine.

[Steve Lee]

I have spent some time this afternoon doing some experiments with a piece of junk film, to see exactly where the optimum distance is, to produce the least amount of wow and flutter when playing back magnetic sound.


Kevin you are right, I think any roller between 10mm - 12mm will be fine for the job, as there is a little room for adjustment on the tension spring where it hooks onto the tab on the projector.
I have also found that optical sound runs perfectly ok without the tensioner, once it has got up to speed.

After doing some searching online a have found all of the key component parts apart available, this also includes a new tension spring. The only part that would have to be 3d printed is the pivot arm that holds the roller, I don't see any problem in doing this.
Once I have received Kevin's old tensioner, I will have a go at producing one from scratch. If this does the job ok, it could be possible to produce them in small numbers.
As far as I can see there is no difference in passing the film over these covered bearings, than passing the film over the pinch roller in the soundhead, it's the same thing.