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I have an issue with my ELMO 1200D. The take-up reel decided not to spin. The belts are new, and the gears turn strongly. After looking at the white plastic gears at the rear rewind, I see two gears side by side. I see that one gear is set up to lock in the other gear to make the wind-up spindle turn. This is the problem; the wheel moves away freely causing the spindle to stop turning. I can move the gear to lock it in and the wheels turn then turn. Have you heard of this issue before? Any suggestions are helpful.
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Hi Chris,
When you say your belts are new, it makes me ask: has this problem started since you changed the belt? Normally, the motion of the long belt causes those two wheels to move together when you go into forward projection. The fact that they are being forced apart makes me wonder if maybe the belt is on its two pulleys as a figure-8 and not as an oval. This would spin that part of the drive-train backwards.
When you get the take-up reel to spin, which direction does it spin when viewed from the side of the machine with the control knob: clockwise or counter-clockwise? -
The belts have about 3 hours of film watching on them. I did not change the long belt because the take-up reel was strong. The take-up arm turns clockwise. One of the two pulleys will move apart with a light touch of a finger just enough for the gears to move away from the gear on the left.Comment
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Clockwise is correct!
Can you upload a picture of the gears?Comment
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The gear on the right is supposed to engage on the solid white piece when the projector is in the run position and then disengage when in the stop position. However, the gear usually will not engage, maybe 1 in 7 tries.Comment
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Ok,
That all looks pretty good. (-maybe could use a little of the correct kind of lube...). The outer cog has a crack, yet they all seem to have it. (I have a machine that was found new old stock in a camera store with like zero hours on it and IT has that crack!)
Here's a thought: there's that copper-looking sheet metal...thing1 that looks like it's trying to be a really bad tuning fork. It's basic job is to lean on the hub of that rear gear and give it a little drag to force the one gear to climb up the other using the angled cut of their gear teeth.
Is it leaning on the hub?
You can loosen the screw that holds the...thing and lean it towards the gear hub, and then tighten it. It doesn't need to have massive pressure, just a little bit.
Notes:
1) I'm sure this part has a real name...Comment
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I did what you suggested Steve and voila! Wala! These machines are amazing.Comment
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That's great, Chris!
What makes this a little interesting is a couple of months ago, I had the same cause but a different effect. I changed the long belt on one of mine and pretty soon I noticed that I couldn't rewind a reel with more than 400 feet of film. I opened it up and found that under rewind, the spindle was failing to disengage from the gearing and rewind was dragging the long belt too. The additional required torque was enough to overwhelm the clutch on the supply spindle and the rewind ground to a halt mid-reel.
The Elmo Patented Frictional Gear Drag Device (Pat. Pending) wasn't touching the hub at all, and the two cogs didn't separate. I adjusted the...thing to drag on the hub and it's been just fine ever since.
What's the difference?...-not a clue!
What's kind of fun about these mechanisms is there is actually a very simple set of logical operations going on here:
If the transport is driving the long belt, then engage the drive to the take-up spindle.
If the transport is stopped and the take-up spindle is being driven backwards, then disengage the drive and allow the spindle to freewheel.
In our century, the designers might automatically fix this kind of thing with software, in the 20th century, a clever Mechanical Engineer took care of it!
(THIS is why when the windshield wipers went berserk in one of our cars, part of the fix was a "Firmware Update"!....sighhhh!!!)Last edited by Steve Klare; October 26, 2024, 03:26 PM.Comment
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I think that cracked gear is one of the ones than Van Eck sells. I replaced all my cracked gears with the ones from Van Eck, but I'm not looking at the inside of my machine right now as I type this.
If that's the one that separates, then yes I replaced it, because for awhile my ST-1200HD was slowing down during rewind for the last 100 feet or so, and needed help. Turned out I didn't leave enough room for the separation and the take-up reel wasn't turning freely during rewind.Comment
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I replace the cracked gears on my ST800 and ST1200 with Van Eck gear... And also adjusted the tension. Everything works much better now.
https://8mmforum.film-tech.com/vbb/f...8000#post79555Comment
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What woud we do without Van Eck?
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