Problem with Eumig Mark 709

[Brett McDonald]

Hi guys, I have a problem with my projector. Take a look at the video clip and see if any of you know how to help. I live deep in the Bush in Botswana and have no access to a professional shop

[Douglas Meltzer]

Here is Brett's video:

[Steve Klare]

Hi Brett,

The machines I know have cams on the control knob shaft activating switches. Yours is acting as of there is some detent also on the shaft to provide stopping points for the knob which has gone out of alignment with the cams.

[Brett McDonald]

Hi Steve, there is one detent and it drops into the lock position correctly but slightly out of sync for running the unit forward. There is absolutely nothing in reverse.

[Steve Klare]

Is there some means of adjusting the alignment of the detent and the switch closure?

I'm imagining some grub screw down inside the guts of the machine that maybe has loosened up over the years and allowed this slippage.

[Brett McDonald]

There is a motor on fumble that can move between two fly wheels. It appears that it will touch the one wheel if you hold the switch lever in exactly the right position

[Steve Klare]

I got the impression from your video that the motor itself wasn't spinning until you fiddled with the switch. Is it actually the case that the motor is actually running, but isn't spinning the drive disk without your encouragement?

[Brian Fretwell]

Most sound Eumigs had the motor spinning as soon as they got plugged in.

[Steve Klare]

Brian,

Is the blower mounted on the motor shaft?

(I've never had mine apart...)

[Joseph Banfield]

I could be wrong but the pressure put on the rubber discs through the ball riding on them is critical....too much pressure in one direction means the motor will stall...too little and it slips. The fact that you have to turn the control knob slightly backwards to get the mechanism running seems to indicate too much pressure being applied in the forward direction. Have you checked the motor mounts to be sure they have not crumbled away? That is a common problem with this drive mechanism. It is also possible if you are not the original owner of this machine that the motor position could have been altered in an attempt to cure the all too common Eumig drive disc problem.

[Joseph Banfield]

BTW, the cams that control your lighting are working properly. The 709 is my go to machine for projection of super 8 film. It is a tough machine to work on though since that tube amplifier takes so much space inside the machine. Hopefully you will be able to resolve your drive issue with this machine as this model and the 701 (dual guage) are really good machines with advantages over the cheapened 800 series that later followed. I posted a review of this machine a couple of years ago in the old forum if you want to do a search.

[Terry Sills]

Joseph is correct regarding the critical pressure of the spinning disc on the rubber Drive wheels. The common fault is the plastic motor mounts which crumble over age, which affects the true angle of the spinning disc thus causing this problem. If they have crumbled it means a strip down to get to motor mounts. You need to preserve the motor bearings and it is possible to remake the mounts using a resin ( something like Araldite or similar) and set the bearings in the resin. A fiddly job but I have done it successfully in the past. Other than that there is an online company that I believe sell these mounts ready made.
van-eck.net based in Holland I think.

[Maurice Leakey]

The 709 is now 52 years old. The Eumig drive design could always be a problem. Steve and Joseph's comments are very helpful is this respect.
Good luck.

https://van-eck.net/img/itable/image...8935313149.jpg



Maurice

[Brett McDonald]

Wow Guys... great feedback, thank you. So I can see that the motor is on a gimble mount, I could not see how to remove it. Do any of you know how?

[Terry Sills]

If I remember correctly you firstly have to disconnect the electrical connections to the motor. I think two are just spade connectors and the earth is a nut and bolt. Once done undo the fixing screws that secure the nearest motor mount, then you can remove the complete motor assembly. You can then access the other motor mount. Removing that one can be 'fiddly'. Before you do all this examine the plastic motor bearing mounts to establish whether or not they have deteriorated. If not it may be that as Joseph previously stated, that the mounts have been moved by a previous owner. There is provision for slight adjustment which sometimes can overcome the problem providing the plastic hasn't crumbled. Good luck.

I should have said of course that this work is done from the rear of the projector, after removing the rear cover.