8mm Forum: ELMO ST-600 D-M...speed adjusting ?

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Posted by Niels Peter Buch (Member # 3757) on May 26, 2015, 06:49 AM:

Hello 8mm projector fans!
How to adjust speed ?....My ELMO ST-600 is going a bit to fast.
25 frames per minute after overhaul and fitting new drivebelts.
Any kind of information is appreciated.

Kind regards !

Posted by Mathew James (Member # 4581) on May 26, 2015, 07:19 AM:

Hi Niels,
I have the elmo st180M(pretty much same thing as yours) Are you certain the middle belt is on the correct pulley for your voltage? I would figure that out first depending what voltage you run where you are. You can have speed variation if on the wrong pulley.
Also, Does your model have variable speed per chance? The capability of variable speeds (two adjustable potentiometers on circuit boards inside the back cover) may exists so you can adjust to 20 fps for video transfer of your home movies, but if you didn't change this and it worked prior to belt change, I would check the middle pulley placement.
Cheers,
Matt

Posted by Steve Klare (Member # 12) on May 26, 2015, 08:40 AM:

As far as I know ST-600 and ST-180 have two speed adjustment potentiometers (one for 18 one for 24), and no compensation for line frequency (DC Motor.)

You have to be patient with these. When I put a new motor in my ST-800 I dialed the pots in to the right speed but found that the speed continued to change after I "finished" my adjustment.

It seems between the electronics of the speed circuit and the inertia of the mechanism there is quite a lag time before the film speed catches up with the setting.

-you can chase the film speed all over the place if you twist that pot too far.

-small adjustment, let it settle, small adjustment, let it settle....

I think Niels' new belts are getting more traction and he doesn't need such a heavy foot on the gas any more to reach 24FPS.

Posted by Niels Peter Buch (Member # 3757) on May 26, 2015, 03:12 PM:

Hello Mathew and Steve.

This model has only one pulley and one pot-meter as far as I can see.
Placed low, behind the cover (main shifter .vu-meter -volume tone etc.)
Perhaps the pot-meter adjust both 18 and 24 frames pr. sec. ?

Kind regards !

Posted by Steve Klare (Member # 12) on May 26, 2015, 03:38 PM:

Usually there are two pots, one right next to the other. These aren't the little blue cubes with a brass slotted head you usually see, but semicircular metal parts set on edge with a driver slot going all the way through.

Something like this:

Posted by Edwin van Eck (Member # 4690) on May 27, 2015, 01:43 AM:

We have a nice kit, with instructions, how to modify your Elmo projector so that you can regulate the speed using a potentiometer on the outside of the projector.

See: http://shop.van-eck.net/digitize-diy/p-1a/PA-0006.html

(we also have these kits for other brand of projectors like Bauer en Noris)

Posted by Dominique De Bast (Member # 3798) on May 27, 2015, 02:03 AM:

Edwin, I see that you're selling a fps measurer. Does it work for any projector and is it easy to use ?

Posted by Andrew Woodcock (Member # 3260) on May 27, 2015, 04:06 AM:

Edwin, what I would like to see if at all possible, is a kit that I could fit to my Bauer that would "lock down" the speed to precisely 24fps.

A member on here was looking into marketing such a device but apparently it never materialized.

I use my Bauer T610 very regularly for recording work so it would greatly benefit me if it was running constantly at precisely 24fps.

It already runs very accurately but I do have to make minute tempo adjustments while locking down the pitch from the digital masters to ensure the two stay in sync.

If the projector was regulated as good as a quartz mechanism, then the only adjustments to the master digital tracks I would ever need to make,would be to find sync speed right at the beginning before commencing transfer.

Please let me know if you feel such a device could be developed and marketed. Also I would be interested in any update you may have on the manufacture of new copy sound heads we spoke of.
for example:- Woelke 464 etc etc.

Thanks Edwin.

[ May 27, 2015, 06:25 AM: Message edited by: Andrew Woodcock ]

Posted by Edwin van Eck (Member # 4690) on May 27, 2015, 06:41 AM:

About the speed measurement meter. This works for all projectors. Just put it before the lens and you can read the speed: http://shop.van-eck.net/?_globalsearch=dv-0038

About the Bauer 24 fps speed. The Bauer studioline projectors have a feedback mechanism which enables this projector to run exactly the same speed. So, if you adjust it to 24 fps with the internal potentiometer (e.g. using above measurement device), the projector keeps running exactly at that speed.

Posted by Dominique De Bast (Member # 3798) on May 27, 2015, 07:31 AM:

That's an usefull accessory for old silent projectors that have a speed control knob without precise marks ! I've ordered one.

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