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Replacing Belts on Elmo ST1200

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  • Replacing Belts on Elmo ST1200

    I'm trying to replace the belts on my Elmo ST1200 and although I bought the new belts I'm hesitant to do it without knowing exactly what the steps are. I would imagine I have to remove the flywheel in order to reach the area where the belts need to be replaced. I've tried looking on YouTube and there isn't anything specific to the two black belts that connect around the shutter area. Nor is there any on the 8mm Archive. There is only one belt on the projector now and I know there are slots for two belts. Anyone know of a video or a manual that might aid me in this replacement? Would be much appreciated for any help. Thanks everyone and stay safe.

  • #2

    carefully flex the belts they should slip between tight spots


    • #3
      Chip, do you mean "nope" to taking out the flywheel? I imagine that's what you're talking about. Thanks for your response//


      • #4
        This video shows where the belts go. You do not have to remove the flywheel.

        There is a forth belt you might receive that is to go onto the shutter. This is optional. Steve Klare put it on his ST1200 shutter...he wrote a description located in the archives... it's not easy. I chose not to and it runs just fine without that belt.;f=1;t=010066

        Whether you choose to replace the shutter belt or not... you will have to cleanoff rubber any residue left on the shutter wheel down to the metal. Be careful not to cut into the soft metal.

        Here is also a YouTube video showing a DIY solution if you chose to add a shutter belt. I'm not recommending this...just providing it as an alternative option.
        Last edited by Janice Glesser; August 23, 2020, 05:52 PM.


        • #5
          Correct. There should be NO reason to remove the flywheel for just changing belts

          Also which ST do you have. The very early models required round belts the later ones required poly-V square and I don't think they were interchangeable

          Do some homework so you get the right kinds


          • #6
            Thanks Janice and Chip- I think I may have jumped the gun and installed the shutter wheel rubber covering as described in one of the videos.You can see it in pic 1. This does work better than before in that I can go forward where before I couldn't but at an erratic 24fps. When I switch to 18fps the smaller of the rubber wheels pictured does not touch the shutter wheel at all. It makes me wonder if some adjustment to the pivot with those screws will be of help but won't touch a thing until I know what I'm doing.

            I looked at the second video Janice recommended (2nd photo) which is a 1200 st and was surprised to see that it doesn't have the same insides as mine. I have a metal spindle (3rd wheel down from two rubber ones- 1st pic)and the one in the video (2nd photo) has none. This probably is what Chip is referring to as a different model 1200st/ Mine has no counter btw. It's the wrong threading pictured as I can't squeeze the belt safely under the metal spindle (pic 1). Any help there appreciated. BTW they sent me two belts, one is a larger rounded cut variety and the othere is the Vsquare which is installed. I can't figure yet where the longer rounded one goes, if anywhere. Did I do wrong by making the orange 'gasket' for the shutter wheel? I can take it off if necessary/ In the video (pic2) I see no such coating on the shutter wheel, just bare metal. Any further help greatly appreciated as I move forward.

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            • #7
              Yes. Yours is poly-v

              lets be clear that as far as I know shutter belts are not to be confused with later versions of the machine that actually had a black rubber ring attached to the physical shutter blade itself

              In other words let's make sure we are talking only about belts

              If your actual shutter blade has a black rubber ring around it do not attempt to touch it it is a very tricky complex job to replace that one leave it for a technician if you think it must be done

              If your machine is older and the shutter blade is all metal then you have nothing to worry about


              • #8
                Thanks Chip, yours is good advice. My ST1200 wasn't the kind with a black rubber ring. Therefore, I took off the orange coating I mistakenly put on, being careful not to scratch the shutter wheel and took off remains of rubber cement with mineral spirits and a q-tip. I then threaded the new poly v correctly per Chips instructions (Carefully). Now I have a working projector that goes steady at 24 fps! For some reason I can't go at 18fps as the switch doesn't work , as I don't use this projector for anything but sound film it's not a big deal, however I'd like to fix it at some point. Janice mentioned in a PM that it may be just the spring on the clutch that needs replacing and sent me this link.


                Last question-what does one use to grease the plastic gears inside the projector?


                • #9
                  I recommend Superlube.