Hi all, I really didnt know where to post this so feel free to move it.
I need to some how make or buy a friction or slip clutch to go between my stepper motor and a 3" reel.
Could someone point me in the right direction?
Best regards
Dave
You can usually stall a stepper (it'll just bump-bump-bump) without damage. They can be overdriven as well. What at you trying to do? You can buy both hard lock and slipplable clutches with electric actuators.
I don't know but maybe just reduce the voltage to the motor?
In most applications that would defeat the purpose of a stepper, since the software is normally keeping track of the steps and position.
Years ago I bought the sample machine and all the supplies for a machine that would wind fish line from a spool onto a commercial fishing reel. Part of the design was a slip clutch to drive the various sizes of reels. The clutch was a a pair of steel plates, round in shape, with one plate covered with a cork based material. IT would slip if too much torque was applied.
You can make something similar. I gave away all the cork material and recycled all the rest as I was never able to get the project plans from the estate of the owner.
You can use any cork material to make your slip clutch if you don't let it slip to much, too often, so it gets hot.
This is the key for anyone trying to help you.
Ok peeps. im making a 8mm cine film scanner. very similar in design to an old reel to reel audio player.
as the film gets pulled onto to take up reel. the diameter increases, which means in order to keep up with the film being passed thu the takeup reel will need to slow down. as i cant work out the math for this i decided that either a slip clutch OR a pully on a spring would do.
I'd welcome any other suggestions as im drawing a blank and have limited funds.
I was thinking about reducing the current to the stepper so that its still able to move the reel but also able to slip if the force was to much. but i was worried about damaging the stepper or breaking the film. im not tracking stepper positions. just needed percice control.
Why not make it like the old film projectors and use coil spring drive belts with pulleys to hold them. They worked really well at doing what you are attempting.
wow, very expencive. but think you tho
never heard of them before. do you have examples?
When I get time, I will pull out my old 16mm projector and take a picture for you. Or you can Google for 16mm projector images and see if you can see the reel drive mechanism.
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just had a quick google. where on earth would I get a spring that long? wouldnt a loose rubber band or wrong size belt do the same job? also. trying to do that I would need to redesign my project. i never though that tryin to build this would be so complicated lol
Contact some camera repair shops. They repair all kinds of stuff relating to photography, including movie projectors.
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wouldn't the magnate interfere with my stepper motor? Also, how does it work?
No.
The spool of string module has a magnet on the bottom.
The motor has a washer slightly indented into a well in a disc.
The spool’s magnet inserts into the motor well.
The magnet is free slip on the washer if need be.
The power of the magnet keeps things coupled.
Ignore the wooden module on the left, this module is locked in place with its magnet.
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oic, i get it. very smart. i wonder how I could use that with my setup??? perhaps if i sent you pictures??? you might be able to work out how i could do it maybe?
Handle things here, others might have ideas too.
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I’m sure you can come up with a solution using magnets.
A spacer between the magnet and washer can adjust slippage strength.
There are many different shapes and sizes available: discs, rods donuts, balls etc.
Ex:
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