Pinch Rollers Whats going on with my model
Pinch Rollers Whats going on with my model
(OP)
I have 2 rollers of the same thickness (5mm) made of TPU98(soft rubber)... They are to move 8mm Supper 8 film pinched between them.. The Idler roller is 23mm diameter and can be forced against the main roller using a 3mm screw.. the main rollers diameter is larger at 30mm and is being driven by a stepper motor.. Problem is:: The main roller just slip's not driving the film. yet if I hand spin the Idler (smaller) roller it grips the film great and the film moves...
is this normal that the smaller roller should also be the driver having the stepper..??? If I "squish" the rollers together too much the friction will stall the stepper motor..
Any comments or suggestions would certainly be appreciated...
is this normal that the smaller roller should also be the driver having the stepper..??? If I "squish" the rollers together too much the friction will stall the stepper motor..
Any comments or suggestions would certainly be appreciated...
RE: Pinch Rollers Whats going on with my model
RE: Pinch Rollers Whats going on with my model
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Ohm's law
Not just a good idea;
It's the LAW!
RE: Pinch Rollers Whats going on with my model
RE: Pinch Rollers Whats going on with my model
RE: Pinch Rollers Whats going on with my model
RE: Pinch Rollers Whats going on with my model
A metal pin will cause a sharp bend in the film. If the holes are too delicate to touch then just drive the take-up reel and sense when a frame is in position. Add a light friction drag, though the frame should be held flat enough by the film guides.
RE: Pinch Rollers Whats going on with my model
the large stepper will stall, that much pressure in unacceptable.. We had a design that worked, But it got deleted. We have no idea what the roller demention's were.. again, thanks for the input.....
RE: Pinch Rollers Whats going on with my model
Something to note is that the film has emulsion on one side and has a different friction coefficient which is likely why the one roller works and the other doesn't.
Anyway, it sounds like there is far too much drag on the film.