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Can I change Speed on Elmo ST1200D.

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  • Can I change Speed on Elmo ST1200D.

    I have cleaned my Elmo ST1200D, and it is working nice and much more quiet.
    Watching a movie, it's like it is running on 20fps instead of 24.
    Going to 18 and back won't help.
    Can I change the Speed on an Elmo ST1200D somewhere?

  • #2
    Good Aftenoon Matthieu,

    Within reason, the answer is "no", because these have AC motors and the frame rate follows the frequency of your house current.

    I say "within reason" because on the very odd chance you could convince the local power plant to spin their generators faster, all of your neighbor's electric clocks will run fast!
    (You don't want to be that guy in the neighborhood: people arriving at work an hour early just so your sound tracks sound right! 😁)

    To me this machine's problems with speed regulation is their big weakness: it's kind of sad considering how good they are otherwise. Most Elmo machines have DC motors and electronically regulated frame rates and do much batter along these lines. My AC motored Eumig also does pretty well: its just a different design.

    There are some things you can do about it, though.

    I find if I let one run a few minutes before I load a film, it picks up speed.

    I found that cleaning the glop out of the worm gear and re-lubing helps.

    https://8mmforum.film-tech.com/cgi-b...c;f=1;t=009552

    On this same machine I also found that wear of the motor pully sheave made the diameter of the pulley effectively smaller, and replacing the motor pulley also improved the frame rate.

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    • #3
      Steve cant one of the belts be changed?

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      • #4
        If a belt was stretched or of the tensioner wasn't set right, either of those could make a difference.

        I also replaced the rubber surface on the shutter wheel and I think that helped.

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        • #5
          I tightened the take-up arm gear spring, so it can carry the 1200" reel, see Janice Glesser's photo.
          But i already had this soundproblem before, but maybe less.
          Attached Files

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          • #6
            A few of my projector take a mintute or so to get up to speed in the winter!!! I don't feel the cold much, so my rooms aren't very warm!

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            • #7
              I always turn On the projector when I'm ready to put in the film.
              But from now I must keep it running a few minutes and not stop first when I'm adding a reel.
              i also stop the projector most of the time to rol the film on the take-up reel.
              i thought it is bad holding that reel stil when it does not pick up the fklm correctly.

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              • #8
                What I now discovered, that when I press the 18/24 switch up, it goes faster.
                Maybe it is indeed the cold that shrinks the belt.

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                • #9
                  did the shutter originally have the rubber around it? I had a 1200HD but the rubber turned to goo and ran it for years without it and it ran ok is there an a adjustment for the 18/24 setting?

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                  • #10
                    Originally all the ST-1200s had rubber around the shutter. I replaced mine:

                    https://8mmforum.film-tech.com/cgi-b...c;f=1;t=010066

                    The problem is the switch from 18-24 is by this cumbersome rocker assembly that has some adjustability to it in terms of how it is mounted to the chassis. I haven't had a lot of luck with it: basically I get it to work and not mess with it! (This machine has not seen 18 FPS since 2010!)

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                    • #11
                      I have three st-1200. Two of them have the clutch set to 24fps permanently. Sometimes on a cold day it can take a few mins just to get up to speed, and the rubber can be a little noisy until it all warmes up. However its always good to check/ change the belts too at certain periods. They can be good for years and then suddenly weaken. The st-1200 were designed to hold 1200ft of film so there is no reason to doubt that, otherwise they would have been designed for 800ft max capacity.

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                      • #12
                        This is my original ST1200 bought second hand way back in 1979 I agree they are totally touchy regarding speed and as with all film projectors need a warm up period. I am not sure that these very early models ever had rubber around the shutter, they may have but never come across it with this early 1970s "M" model. I used it just the other night, speed wise its fine for both 18 and 24fps, in saying that I have done adjustments to that rocker in the past. In particular getting the spring tension just right for the rollers contact. The rocker is really a pain to get right, so I can certainly see the need for a thin rubber band around the shutter. A couple of things you can do is to adjust your belt, get it nice and tight, plus place a small drop of light oil on the back of those rollers just where the circlip is.

                        After that hope for the best it works, thinking back of when I did those adjustments I found if I got the speed right for 24fps I started to lose the 18fps. If I adjusted things for 18fps I started to lose speed with 24fps a bit like a cat chasing its tale so all the best with this one. I think it was a failing with the original design with the ST1200 I wonder if fitting a stronger spring would work....best of luck

                        Click image for larger version  Name:	P1350960.jpg Views:	0 Size:	167.3 KB ID:	96157
                        A single drop of light oil applied on the back at the circlips might help.
                        Click image for larger version  Name:	P1350962.jpg Views:	0 Size:	151.7 KB ID:	96158
                        Click image for larger version  Name:	P1350963.jpg Views:	0 Size:	83.9 KB ID:	96159
                        That chrome idler wheel above is for adjusting the belt tension, it might be different on the later models, I don't know.
                        bottom photo from the other night
                        Click image for larger version  Name:	P1350863.jpg Views:	0 Size:	127.3 KB ID:	96160

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