Set the high limit for speed control on Eumig 709

[Todd Kitchen]

is it possible to adjust the high limit (so that the spinning horizontal metal wheel makes contact with the rubber forward/reverse disks "higher up" or closer to the center.

My new 709 plays 18fps quite accurately, but the switch doesn't slide all the way up to 24 and as a result, at it's highest speed the projector is actually clocking something like 22 fps, so sound films shot/printed at 24fps are incorrect. The voices sound noticeably lower/slower than they should.

Is there a a way to make this adjustment WITHOUT having to remove the pivot motor from it's mounts? There's got to be an easier way to adjust upper/lower limits for this mechanical contraption.

On my 802 I successfully got the high/low limits but I had to pull the motor out slightly to get the metal disk to seat between two plastic "limiters" They look sort of like retractable vice jaws that are controlled by the film speed slider switch which engages them so that they can push the spinning disk higher on the rubber wheel for a faster speed, lower for a lower speed.
Once they're done moving the disk they retract out of the way to prevent the spinning disk from rubbing against them.

But On the 709, it appears that the mechanism to move the drive disk is different. Since I now have a "donor" 709 parts machine, I can experiment on it before actually taking apart my production machine. I messed around on the parts machine a bit and it seems like it uses some sort of ball bearing to slide the metal drive disk up/down. I just can't see how it's adjusted.

[Melvin England]

Todd - I cannot speak for the Eumig and I am certainly not an electricity wizard. But I had a problem with a Sankyo 700 a long time ago. It was just running too fast at both 18 and 24fps. (It didn't have a variable speed control like yours)
A friend of mine told me to open the back of it and somewhere on the circuit board near the motor, was a variable speed control for the motor, which, in turn slowed the motor down slightly to the correct speeds. It was a small disc that had a small groove for a small flat ended screw driver.

This may be what you need to look for. A way of altering the MOTOR speed so the correct frame rate on your variable speed control come into range.

BUT.....

Please PLEASE remember to do this WITHOUT the machine switched on as I wouldn't want you to get an electric shock (or worse) because you touched the wrong bit. I know this sounds like a catch 22 situation, but it is always best to be safe and to take more time about it..... and BE SAFE.


If any of our mechanical engineers could add to this and advise Todd further, I for one would be very grateful.

Good luck, Todd, and be VERY CAREFUL.

.

[Todd Kitchen]

With the way Eumig's are designed, I am pretty sure the main motor is already running at the right speed--the position of the drive wheel on the rubber disks determines how much of that power gets to the film transport. It's 100% mechanical. I just need to adjust the little thing so that the drive wheel can engage the rubber disk closer to the center of that disk and thus the main drive would run at a higher RPM and thus a higher framerate.

[Steve Klare]

OK, I'm not a Mechanical Engineer (Electrical), although I would have been happy to go that way too! (My High School had Electronics, so...)

-but as I understand these (-at least from my experience with 800 series), the compensation for AC frequency is done by adjusting the limit of the wheel's range of travel on the disk. If you have 50 Hz, the AC motor runs slower, so the "gear ratio" established at the disk has to allow the transport to operate faster at a given motor speed, so the limiters move up to open those "faster" regions of the disk. On the other hand, if you have 60 Hz, the motor will be running faster, so the range of area on the disk needs to be so the transport runs slower at a given motor speed.

So step one is to make sure you are adjusted for 60Hz, since like everywhere else in North America, that's what you have.

(Maybe try the 50 Hz setting. It will boost the speed by a factor of 6/5 when used with 60 Hz. power. More than enough)

[Todd Kitchen]

So you're saying that I can avoid having to tear apart the whole assembly (which is very finicky) by changing from 60 Hz to 50Hz? I will try that.

[Shane C. Collins]

Todd, adjust the black flag above the motor that is labeled 50 hertz and 60 hertz. This will lower or raise the ball so it hits the rubber at a different spot. Try this with the back off and some sound film loaded and ready to go. Just be careful as you can get a shock with that rear cover removed. It may have gone out of adjustment slightly during restoration. Do not mess with the 50/60 hertz transformer taps. It's set to 60 so keep it there...😁

[Todd Kitchen]

Thanks for the reminder that this is a tube amp and thus a bit more dangerous to work on "live." Or even powered off, if the filter caps haven't drained.
Always keep one hand in your pocket and use a non-conductive probe like a chopstick to touch things is the rule I follow if I don't know if all the dangerous voltages are discharged.

[Shane C. Collins]

So Todd how did you make out?

[Todd Kitchen]

I got it to play 24 fps absolutely bang on, but now it plays 18 fps just a bit fast. It seems that the flag needs to be either/or 50/60 but not in between? There was one flag position where I got terrible warble from the mag track.

I'm still getting a feel for how to thread this thing. Lower loop size is important. The reels must be all the way in--fully engaged. Also discovering some older leader can be shrunken so getting stocked up on white leader.

Is there some sort of loop restore button? I can't figure that out either. I lost the loop a couple times watching some sound footage. Usually just reversing directions fixes it. I think I'm missing something.

Another mystery: There is a button on the very top near the handle. It's a white push button. It turns on a light down by the volume control, but I can't figure out what it does.

[Joseph Banfield]

Todd, the loop restorer is the same gray button you press when loading the film. Pushing that will restore your top loop if lost during projection.

The button next to the handle is for enabling the sound on sound recording feature. For example adding narration to a previously recorded music track.

Threading is pretty straightforward by following the arrows that are printed on the machine. Before entering the soundhead and pinch roller block there are two arrows marked on the machine. If projecting Super 8 sound film you thread the film by following the arrow closest to the soundhead block which forms a very tiny bottom loop. If running standard 8 sound film you thread following the arrow that is further away from the soundhead block which gives a much larger bottom loop. Both film standards have a different picture to sound seperation requirement. Super 8 uses 18 frames of seperation and standard 8 requires 54 which is why the bottom loop varies in size between the two film formats.

The speed regulator when it is set at 24fps and is running that speed properly automatically sets the bottom of the downward stop to be set at 18fps. In other words if you adjust for one speed you will affect the other speed too. The spacing is preconfigured in that once sound speed is set at the factory the silent speed will be at the opposite end of the sliders travel. If you feel 18fps is a bit too fast then perhaps the film itself was shot at 16fps or slower in the camera.

[Shane C. Collins]

You may have to move the flag just slightly one way or the other so both speeds are bang on. You'll have to experiment with the back off. Both speeds were accurate before I shipped the unit, but things could have been bumped around during shipping. I think you will get it just keep making small adjustments with the flag. My Mark S Super 8 machine was like this until I found the sweet spot.

[Todd Kitchen]

Could you film a youtube short showing your threading technique? I just want to see how you do it.

How I've been doing it:

After I use auto-thread to get through the film through the pressure plate, I then turn off the drive and thread the film thru the slot, then manually wrap the film around the lower sprocket wheel and then use the inching knob to test the entire path.

Is that how it's supposed to work (1/2 auto; 1/2 manual)?

[Shane C. Collins]

Yes after going through the gate continue to run the projector until about a foot of film comes out. Then slide the film in the sound head area and up around the rear sprocket and film guide to the take up reel.

[Shane C. Collins]

Todd, I will try to make a video some time this week. I work 4 ten hour days with Friday, and the weekend off. Time is always against me early in the week, LOL.

Just to recap:

Push the threading lever down and insert the film. As the film exits the gate let go of the lever. Continue running in forward until about a foot of film exits. Then flip the lever to stop, machine idle. Then manually insert the film through the sound head area. Then pull enough film for either Super 8 or Standard 8 for the proper loop, Hold the loop with your finger, and insert the film into the rear sprocket. Close the shoe, and wrap the film up and around the rear guide and onto the take up reel. Run the projector to make sure everything is OK. Remember for silent films the loops are not needed, although I still use the loops as it seems to keep the film running quieter. Also something I do when threading sound films, is to use the 18 fps speed, until I have the film onto the take up reel. I then flip the lever to 24 fps. I found it makes threading smoother with less mishaps, since the film is running that much faster through the gate upon initial set up at 24 fps.

Also remember to switch the amp to off when running silent Standard and Super 8 films. This puts less wear on the heads, etc.

As a side note, I also agree with Joseph that some of your silent films may have been shot on 16 fps. That was common until the early 60's, however some users continued to shoot this way well into the mid 60's. Not all users switched to 18 fps when it became common, by the time Super 8 was released, in 1965. Your silent Super 8's should be 18 fps. Have you tried these on the 709? I would verify those films that you know were shot at 18 fps and play them on the 709. Those films, and your sound films at 24 fps should tell you if everything is set up properly speed wise.

[Shane C. Collins]

Todd, here's a quick video I made showing how I thread the 709!

https://www.youtube.com/watch?v=uq-8TiL9V-w