Not too sure how many will respond to this, I look at the numbers who read threads here and am always dismayed at how it tends to only be the usual handful who join in, however i'll ask the question.
Reading elsewhere about this topic, and it has been well covered in the past, I saw a link to a youtube video which shows a bloke doing a repair to replace the rubber on the outer edge of the shutter on 1200HD. The reason for the repair was the usual problem, it had turned to gool, it made me wonder if my own fix many years ago was a bit overboard.

A few people have said "Elmo produced this rubber for a reason", to me, all it does is give a slightly quieter run however, my own 1200HD without the shutter rubber, is quieter than most others, and Bill Parsons even commented on this me the first time it was sent to him.
Replacing that outer rubber seemed to look relatively easy on the youtube video, but my own fix was to take out the machine frame assembly that holds the shutter and claw and completely remove the shutter. I sent it to a precision engineer who popped it on a lath and very carefully machined the edge of the shutter to a perfectly flat level surface so the drive wheel sit on the full surface on the outer edge of the shutter. This allowed me to do away with the rubber altogether which obviously ensures the problem will never happen again. At that time, I also had new 24fps clutch wheels made and a new all metal lower pully, this had the grooves a slightly different diameter to take up the speed difference when the shutter rubber is removed as the shutter diameter becomes a very slightly smaller size. My first one was a 100% success, the second one I did had to go to Bill as for some reason, I could not get the 24fps clutch to make contact with the shutter, bending springs and forcing as some people have done is not the way to go.
What Bill did tell me at the time he had my second Elmo was that using the original lower pulley was fine as the size difference was virtually unnoticeable on the speed, and he was right as always. All three of our 1200HD no longer have the burden of the rubber edge on the shutter and they all run perfect.

Has anyone else done this repair? If so, did you replace the rubber or remove it altogether?

I had it on one ST1200 that went to goo, I just spent time cleaning everything and never replaced the rubber, the machine still runs nice and quiet, if I thought the sound was affected by not replacing the rubber then I would have looked into getting something sorted, Mark

I think the jury is still out on whether all Elmo ST-1200HDs originally had the rubber or not. I have 2, and neither had the rubber when I received them (used.) Of course, some did have the rubber originally. I'm not sure about the other ST-1200 models from Elmo.

My ear is very sensitive to wrong pitch for voices, (like Laurel and Hardy), and other than noticing that the speed can be a bit slow until the machines warms up, I've never noticed a problem.

In term of adding the rubber, if you are not having speed issues, then leave it alone. If it ain't broke, don't fix it.

Some 1200HDs didnt have the rubber, so far,none of ours have needed warming up to get ti speed.i project from first off with no problems. Could be yours may need some lube or a good service. The one projector make my Brothers always had with slow start up or slow down during projection is the Eumigs,that crappy slipping clutch system
Thankfully the elomos are much more reliable.

Quote: Tom Photiou wrote in post #4

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Some 1200HDs didnt have the rubber, so far,none of ours have needed warming up to get ti speed.i project from first off with no problems. Could be yours may need some lube or a good service. The one projector make my Brothers always had with slow start up or slow down during projection is the Eumigs,that crappy slipping clutch system
Thankfully the elomos are much more reliable.

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I still have the 810D LUX I bought a year or so ago for next to nothing, mainly for the suprogen lens it had which now means we have two of these lens's. I bought it as a spares or repair machine. When I got it I realised that the claw pin had been broken off. I've got that sorted but it is so slow in play I've given up for the time being. It wont run in reverse but after a very quick rough up of the rubbers I did get it going all be it, very slow, so what I intend to do with it is use it as the toy these are, I will strip it down as far as I can and get it going again properly. When they run they good little solid projectors, but I dont like the hum they have through the amp and I dont like the restriction of a 600ft spool size. When I do this, I will share it on here as I go but it will be mid to end of May before I start.

This was the thread I started, part one of four.

Eumig 810DLUX claw pin change, all help appreciated

But I will pull it all apart again and this time i'll try and sort the drive side and replace the mounts.

Generally, we use three Elmo ST1200HD's, all modified in one way or another, all done by the best Elmo engineer, Bill Parsons, they have all had the bulb housing and connectors modified, the shutters sorted and even a new film aperture plate on one among other repairs and updates. The Rear green guides have been replaced so the scratching problem has been avoided and also head pressure pads on two of them. It doesn't get any better than that, it is such a shame Bill is now retired but I'll let him off, he deserves a peaceful retirement although I was extremely lucky that he offered to service and repair a very rare Sankyo 880OMS 'I bought which I was very grateful for, this was my thread on that one,

Bill Parsons, A Huge Thank you. The Sankyo OMS880 STEREO

And the other machine we use is the Bauer T610, but i always come back to the Elmo 1200HDs for their excellent screen image, especially when the 1:1 or 1:0 lens are used, and the sound from these is way above the rest although as I found out from Bill, The Sankyo 880 I have has a GS head which results in equally excellent sound quality and with no amp hum.

Tom,

Do you know about the coil on the Eumigs that can be moved to reduced the hum? Very easy fix and the hum is low enough that I don't notice it. Usually the hum becomes a problem when the sound is recorded too low and you need to pump up the volume.

The pin breaking off was the cause of another poor design point of the Eumigs. That being said, I received an 810D as a birthday gift when I was 9 years old, and til this day the pin is still intact. And, I used to change gauges all the time, and still do. If a 9 year old can do it...

So, if you are changing the claw pin, then you are more handy than you have given yourself credit for!

As I've said before, I've always done all my own maintenance. If there was a reliable projector maintenance guy within driving distance of an hour or less, I would consider it if the price was reasonable. Currently, though, I don't have any issues that are urgent or that I can't fix with a little bit of time. I have a few silent machines that I'd like to convert from incandescent to halogen, but I haven't gotten around to them yet -- and haven't fully worked out how to do them yet. (I've done a few in the past, but evey machine is different.)

I have heard of adjusting the coils in the Eumig, I haven't looked into the coils and I am not 100% sure what these are, look like or how to adjust.
I do recall Roger Lily here at Movieland international laying one of these machines on its side and playing with the coils and the noises that were coming from the speaker as he put a screwdriver in there made me shudder, Roger jumped out of his skin as well so I've no idea what he was doing. Apparently, he was adjusting the coils!!!
Like most projectors, if they are used regularly they seem to be fine, but my own experience with Eumigs is aside our 822 sonomatic, every single one has has had problems with that crappy slowing down or just not running more than a few frames. The one decent rubber cleaner I have used on these is PlatenClene, it was recommended by a good friend and it does do the job. Again though, if these machines are left standing too long it plays up again. The claw pin is a stupid design but as you said, if you follow the instruction of putting the white dot at the top before changing gauges, it should never happen. Many machines seem to end up in the hands of dummy's who dont read instructions or perhaps they forget, either way, it's another poor design, a shame, as I have always said, they run reasonably quite, they have a good light output and the sound, (especially on the HQS models) is actually very good, just let down by that awful slipping clutch.

Click on the image to make it larger, and you can see the coil. It is attached to a wire that's flexible. Just move it around with the machine in "fwd with sound" mode, and turn the volume up. You will hear the hum volume change as you move it. Extremely easy.

I highly recommend replacing the motor mounts with new ones from Van Eck. Even if the one visible looks OK, the one on the other side may be crumbling. Even if it is just slightly broken, the angle of the tilt can be off. This may not completely fix the problem, but the problem can never be fixed at all if the motor mounts are broken.

Yes I know the coils now, i'll have a play.
I do have four of the van ek mounts which I bought some time ago so i will replace them when I come to having a go at getting this thing going again.

It would be great if Van Eck could make the rubber disc drives, but since those cannot be 3D-printed I would guess, it is unlikely. Phil Johnson on his site used to sell these, which he said he made himself. If I remember correctly, they cost as much as buying a Eumig in good condition.

I mentioned tightening the spring that provides the force of the motor-ball against the rubber discs. I've never tried that, but I have played around with the positioning of the motor "stops" on the control switch. Over time, these can get out of alignment, plus you never know if previous owners have monkeyed with them. The motor rod/ball should be exactly in the middle of the 2 discs when the machine is stopped. If it is aligned correctly, and you are still not getting the proper speed, you can adjust the stops to favor forward motion. Do this only if you do not care about reverse projection or rewinding with the machine. Also, make sure that the motor-ball does not touch the disc at all when the machine is in the "stop" position. I know this is obvious, but it is easier said than done.

Just to emphasize, other than replacing the motor mounts, only attempt to align the "stops" if the motor is not already dead center. Then, only attempt a spring tightening (with a new spring, or shortening the old spring), or an adjustment that favors forward motion, as a last resort, short of replacing the rubber disc drives, or making a last attempt at roughing them up.

Also, don't discount getting a real junker machine as a donor and using its rubber discs as a replacement. I lucked out on my first try.