Eumig S 710 D Motor Mounts

[Chip Hess]

So I have it as good as it's gonna get. Still off center, but tried everything. Takes a minute to get up to speed but fine after that. Bending the metal - in lieu of the screw adjustment - hasn't worked. Has anyone tried moving the rubber discs slightly? I see two screws that apparently anchor them. If they actually screw into the shaft, then obviously that doesn't work. But if they are held by tension, there is a little wiggle room left and right on the drive shaft. Thoughts...?

[Joseph Banfield]

Chip, you must have bent the levers in the wrong direction, or not enough, if the motor can not be centered.

Yes, loosening those two screws on the center hub of the drive discs will allow the discs to move slightly as a whole but not individually. But if you move them too far to the left they will rub on the projector's cast frame. You also have limits on how far they can be moved to the right due to the worm gear that drives the takeup reel. You will have to experiment and see if that could work for you, but I will tell you that at best the discs can only be moved plus or minus a couple of millimeters without causing problems.

[Brian Fretwell]

I found the earlier forum pictures. Can't remember who posted them

[Chip Hess]

Yes, those screws are not on the 710.


And the spring is behind the casting, otherwise I would have this %#$@!! thing adjusted. Ill take some pics.

[Chip Hess]

Two pics of the same area on the 710.

[Chip Hess]

As you can see, different setup. The horizontal metal bar in the highlighted area
is behind the casting. The two metal prongs on either side are what I assume we are talking about "bending". At one point I removed that top arm with the nylon stop, to reveal the arms riding that cam. Other than the aforementioned prongs, I can't see what could be bent without messing up placement of the arms, riding on that cam. Am I missing something totally obvious...?

[Joseph Banfield]

Yes, it is a different setup like you say, but the principal is exactly the same.

If you look at the photo someone submitted, specifically where the four screws are located for adjustment at the ends of the two arms, you will notice that only the ends of those arms can be adjusted. That is exactly the area where you would need to make slight bends on a machine without adjusting screws to achieve motor centering.

Also you have never really mentioned your exact problem other than the motor centering is not perfect. It could be that even once the motor is centered it still may not run properly. There can also be a problem with that spring that is stretched across those levers. It is known that this spring sometimes fatigues and no longer applies enough pressure to the motor to drive the discs properly.

[Chip Hess]

The machine runs slow at startup in forward. Takes a couple minutes to get up to speed. It runs fine in reverse. Since playing around with it, I have lost the 18fps speed in forward, but again reverse works fine. That spring is almost impossible to get to, as I did consider shortening it to revive some tension. Is it just the ends of those arms - visible in my pics - that need bending, the two prongs? I don't know how I would bend the arms farther down without damage. The prongs seem to be the 'lightest' part of the arms, which get thicker just beneath.

Thanks guys, I can't tell you how much the pictures and advice are appreciated!

[Joseph Banfield]

Before messing with that spring it is necessary to get the motor centered first. The symptoms you mentioned indicate that equal pressure is not being applied, especially with it working fine in reverse but problematic in forward.

Yes, you must bend the tips of those arms until the motor is centered. The easiest way to do this is to remove the motor and fan cover again (by now you must be an expert). From the back of the unit you will need to remove that tiny spring clamp that holds the right hand U-shaped black piece of metal that is covering up the spring and blocking access to the arms. Re-install the motor properly and bend gently the tips of those arms until the motor is centered. Take the motor back off and re-install the U-shaped piece and the motor and try again with power applied. And if after centering you still have problems we can discuss the spring issue.

But one thing is certain, without proper motor centering this type of drive system will not operate properly in both directions.

[Chip Hess]

Looking at it from the rear, the motor clearly sits closer to the right/reverse disk. Then turning the machine around and looking from the front, is it the prong on the right side or left I need to bend? Or both, towards the right so the motor is held in the (hopefully!) new position?

[Joseph Banfield]

Chip, tilt the motor by hand until it looks centered and then look at the levers in the front to see which one needs bent to just touch that gray piece that tilts the motor, after the bend the motor will stay centered. I can not tell you which direction the bends need to be done as I can not see the current tilt of your motor. But if the left one needs a bend to the right to keep the motor centered in its neutral position, you should probably do a right bend of equal distance on the right one too, or vice versa if it happens to be in the opposite direction.

And to answer your question: I believe if looking at the back of the machine and the tilt of your motor is leaning to the right, or the reverse discs, you would start with a bend on the left lever toward the right if you are looking at the machine from the front.

[Chip Hess]

I managed to shift the motor towards the forward disc, bending the prongs. It actually favors that disc a bit, now. But the machine still needs warm up time. After warming up, reverse is fine in both speeds. Forward gets up to speed in 24, but 18fps is too slow. When I manually apply a little pressure to the motor, 18fps comes up to speed. I suspect the spring is not giving enough tension.

[Joseph Banfield]

Yes, the spring will probably need a bit cut off to apply more pressure. But that is pretty drastic and I would only do it as a last resort.

But before you mess with the spring, have you checked the drive discs to make sure there are no grooves worn into them? If so, a sanding usually works to get rid of them if they're not too deep. The problem with the grooves is that the bottom of them where the ball rides can be very slick. If there are no grooves a light sanding followed by rubbing alcohol may help too. Some people also use brake fluid on the discs and swear by it!

[Chip Hess]

Has anyone considered finding a suitable substitute for that spring? I can't imagine it would be that difficult.

[Lee Mannering]

Welcome Chip

Motor mounts. Did one of my 30 odd Eumigs about 20 years ago when the mounts started to crumble.

I used a small sheet of Brass, marked it out drilling the holes and fitted once cut and filed to shape. In the end I made about 40 or so at a cost of £5 I seem to remember which gradually went to new hands needing them.