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Minimal encoder resolution

I have problem with encoders. They count less in one direction so Z axis is going lower and lower.

At the moment I’m decided to change encoders type.
As you know I made my own chain motor mount for top beam. It let me connect any encoder directly to output shaft.
There are magnetic disc and optic Quadrature encoders that will work in maslow cnc.

Do we really need that big resolution?

https://wemakethings.net/2014/05/26/rotary-encoder-teardown/

1000 x 290gear ratio x 4=1160000
Optical encoder “1000” mounted as electric motor encoder will generate 1160000 pulses per one gear box rev. That’s too much :stuck_out_tongue:
Mounted as Output shaft encoder it will generate 4000 impulses

4000 vs ~19600. Not a big difference for me.

The default system has around 8,000 ppr which seems about right to me. I think 4,000 should work with some loss of resolution, but 8,000 would probably be better

2mm/4000= 0.0005 mm per step.
Enough for Z axis.

I wonder is this enough for top beam motors

you should be able to get away with 4000 encoders for the main motors, you can
probably go even lower

4000 steps is ~0.015mm/step, due to the angles, this is ~0.03mm in position. The
target (which we do not achieve) is ± 0.5mm, so in theory, you may be able to
get away with 400 steps/rev

NOTE this is all theoretical, nobody has tried this, and if you try to push down
to this level, the symmetry of the steps will become very important (if it’s
40/60 on/off instead of 50/50 for example)

David Lang

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Ok. Lets test it. I ordered 3 optical encoders from… china :mask:

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