8mm Forum: Eumig S802 speed switch

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Posted by Jonathan Sanders (Member # 478) on July 11, 2007, 06:55 AM:

I just bought one of these machines and it runs fine at 24 fps. But I cannot move the speed selector downwards to 18 fps, using a reasonable amount of pressure. (I don't want to force it!)

I used to have a Eumig (different model) many years ago and I recall the speed selector moved quite easily.

This S802 appears to have been used very little and may never have been run at 18 fps.

Any comments or suggestions, please?

Jonathan

Posted by Gary Crawford (Member # 67) on July 11, 2007, 08:42 AM:

Yes...don't force it down. Back in 69 on my very first Super 8 machine....a eumig 712, the speed thing seized and I tried to force it down and destroyed the whole shaft....it was in repair at eumig for almost six months. I found with other Eumigs...that sometimes just the tiniest bit of light oil...on the shaft on which that mechanism moves will allow it to move again. Take the back off the machine and you'll see how the speed change system works. The movement up or down of the the little lever moves the power ball(that's what I call it) up and down so it hits the rubber drive wheels at different spots on the big wheels, creating different speeds. Be sure you DON'T get any oil on that metal drive ball....or on the rubber wheels....just on the shaft itself. good luck.

Posted by Paul Adsett (Member # 25) on July 11, 2007, 09:44 AM:

And don't move it with the projector running! That will really damage the drive disc. You must have the projector stopped before moving the speed knob.

Posted by Jonathan Sanders (Member # 478) on July 11, 2007, 03:48 PM:

Thanks for the replies. I haven't tried the oil yet, as I'm starting to wonder if I've misread the rather ambiguous booklet instruction about setting the speed.

I knew that it shouldn't be changed when the projector is running - and I've only been attempting it when it was completely off (unplugged). Is that right?

The booklet says:
"Before changing the projection speed, turn the function-selector switch to the OFF position. Then plug in the projector. Move the projection-speed selector up for 24 fps and down for 18 fps. After switching from one speed to the other, allow about two minutes before projecting to give the flywheel a chance to stabilize."

The position of the sentence "Then plug in the projector" makes it ambiguous whether the speed should be selected before or after doing that. (But I guess the flywheel wouldn't be doing anything if it was unplugged!)

The function-selector switch does not literally have an "Off" switch - it's called "Stop" and the motor (fan at least) is running when it's in this position as soon as the machine is plugged in. Is that when the speed should be changed - i.e. when stopped but plugged in?

Posted by Paul Adsett (Member # 25) on July 11, 2007, 04:43 PM:

The projector can be plugged in (and the motor is therefore running), but the rotary switch must be in the stop position (12 o'clock) before moving the speed adjusting knob. In the 12 o'clock position, the drive mechanism is not engaged and the steel ball is not resting on the rubber drive disc, so its then safe to move the drive ball up and down with the speed control slider knob.

Posted by Jonathan Sanders (Member # 478) on July 12, 2007, 06:04 AM:

Many thanks, Paul, for the clarification.
Unfortunately, it made no difference - the switch still won't budge.

EDIT: I tried the oil but that hasn't helped either. The seller suggested I should apply only the tiniest amount with a cloth, which I did using my finger under the cloth. I can only apply it to the lower part of the shaft, to avoid the motor ball.

The odd thing is that the seller, whom I trust (he sells projectors regularly on eBay and has 100% positive feedback), says he tested it recently on 18fps and the switch was fine. But there is so little movement in it that it feels like it's locked in some way (not merely stiff). Perhaps something shifted in transit to me?

Any other suggestions gratefully received!

Jonathan

[ July 12, 2007, 08:09 AM: Message edited by: Jonathan Sanders ]

Posted by Adam Gottlob (Member # 3024) on April 12, 2012, 07:39 AM:

I was reading in the manual (I have an S905) that the speed dial can be turned while running, that it may just take a little while to stabilize. But when I turned it up, the speed went way down, and then the entire projector seized.

I have been unable to get anything to move or turn on (no lights) at all at this point. Any chance I can repair this, or did I damage something significant?

Posted by Thor Andre Karlsen (Member # 3021) on April 12, 2012, 10:23 AM:

If you cant even get the lights on, then it is probably a fuse, since the electric motor should not be in connection with the lights in another way. thats my guess.

Posted by Paul Adsett (Member # 25) on April 12, 2012, 10:44 AM:

The design of the Eumig 900 series drive is much better than the 800 series. On the 900 series there is no problem at all in making precision speed adjustments while the projector is running, in fact this is the main reason I use my Eumig 938 for re-recording sound tracks.
Remove the cover and check the belt.

Posted by frank arnstein (Member # 330) on April 16, 2012, 08:06 AM:

"And don't move it with the projector running! That will really damage the drive disc. You must have the projector stopped before moving the speed knob."

Paul,
I don't really believe speed adjusting while running does actually damage the discs.
One of the tests I always do when buying 800 series Eumigs is to see if they will recover their initial running speeds after changing speed down then back up during testing.
That means slide from 18fps slowest to 24fps fastest and back again to 18fps, while its running, and make sure it recovers its speeds quickly, without disc slippage causing the projector to stall and burn film.
If the projector cannot manage to pass this test, then transmission service is needed. It must pass the test before it can be sold to anyone.
I have never seen any disc damage caused by doing this and can't really see how it could. The drive ball is smooth and round so it moves over the rubber disc surface without a problem.

dogtor frankarnstein
[Wink]

Posted by Martin Jones (Member # 1163) on April 16, 2012, 08:23 AM:

It's arguable whether it does damage or not, but......

824 SONOMATIC Instruction Book... page 6....

"Changing the running Speed"
"Whenever you want to change the running speed, first turn the selector switch (36) to "stop". Only then move the lever (42) to the appropriate position".

I think I would be inclined to credit EUMIG (after all, they designed the beast) with knowing best as to how to use their product.

AND

"After switching from 24 to 18 fps wait for about 1 Minute before continuing projection to allow the flywheel (?) speed to stabilise".
I've queried that as the flywheel is not connected to the mechanism UNTIL you start projection. It should be the "speed mechanism" (lost in translation?)

Posted by Lee Mannering (Member # 728) on April 16, 2012, 08:24 AM:

Jonathan. Just double check the 50/60hz knob in the back to make sure it is not half way. When you turn this it will also move the chrome drive wheel on the shaft as well.

If you ever have a Eumig with a stiff speed change this is what I have done over the years.
1/ Squirt a bit of WD40 on the end of a cotton bud and rub this up and down the inner shaft under the drive wheel and above it.
2/ Squirt a little WD40 above and under the black speed shift knob on the front of the machine with the projector laying on its back. Move the knob up and down to work it in.

Good luck.

Posted by frank arnstein (Member # 330) on April 16, 2012, 08:46 AM:

"After switching from 24 to 18 fps wait for about 1 Minute before continuing projection to allow the flywheel (?) speed to stabilise".

Martin,
I think this would relate to where you had already been projecting at 24fps and wanted to slow down to 18fps in the middle of playing a film. The flywheel would take a short while to slow down enough to allow safe playing at 18fps without the capstan and pinch roller slipping against the film till they matched speeds again.

dogtor frankarnstein [Smile]

Posted by Maurizio Di Cintio (Member # 144) on April 16, 2012, 02:27 PM:

I agree with Frank: switching speeds while the projector is running is not harmaful to the machine itself and I guess Eumig didn't suggest to do that operation while in stop mode just for the sake of the projector but because, if you go from 24 to 18 fps, you put stress on film caused by the flywheel originally turnig at a faster speed (the film acting as an improper brake-device in that case). Only for this reason did they wrote so on their manuals, also due to the fact the speed transimission on the 800 series machines is conceived in such a way the change is really sudden. Indeed the test Frank described is really good to assess functionality of speed transmission. But such a care is not required on Series 900 machines because the speed change is much more gradual allowing for a stressfree rotation change of the capstan. Yet the rubber covered discs may suffer from the same problems as they do in Series 800 due to ageing (hardening of the surface), but you can overcome this with very fine sandpaper to be used on the discs' surfaces.

Posted by Paul Adsett (Member # 25) on April 16, 2012, 03:46 PM:

Yes the speed control on the 900 is very smooth and precise - ideal for re-recording. I have had no trouble at all with my 810 Sonomatic or any of my 926's or 938 Stereo speed controls, but my old S802 runs really slow.
You have to give the Eumig designers their dues - the speed control on the 900's is a brilliant design.

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