Capstan and Cable

No Judgement
1

I was wondering if anyone has tried using a capstan and aircraft cable instead of the sprocket and chain?

Thanks

2

@mbonn Welcome to our group.

It was suggested someone here was going to but I never saw it actually happen.

Thank you

3

Thank you @Bee. I’ll be getting my kit in June so I might try to come up with something between now and then.

3 Likes
4

One idea which was proposed was to use pinch rollers to measure the amount of cable fed out instead of the number of rotations of the motor, I think it’s a slick idea

5

Could you use the existing DC motor or would you need to use an equivalent stepper motor?

Along that line, is a stepper motor with a holding torque of 45Ncm(63.7oz.in) equal to the MaslowCNC DC motor?

6

Could you use the existing DC motor or would you need to use an equivalent stepper motor?

you could use whatever DC motor was appropriate for the size capstan you are
using, that may be the existing DC motor or it may not.

Along that line, is a stepper motor with a holding torque of 45Ncm(63.7oz.in) equal to the MaslowCNC DC motor?

No, the Maslow DC motor + gearbox has essentially infinate holding torque,
because it’s a worm drive that you will break before you turn from the output
side.

This is needed to be sure that nothing moves when power is turned off.

The Maslow is a closed loop design, it has a DC motor and an encoder to tell you
how many pulses you have moved (with config settings to let it figure out how
much chain has been paid out or gathered for one encoder pulse)

Any arrangement where you can drive a DC motor to move things, and have
something tell you what direction and how far you have moved as encoder pulses
will work. The maslow doesn’t care if you do this by having a low res encoder on
the motor before the gearbox the way we do today, or a high res encoder on the
output shaft after the gearbox, or an encoder reading the chain (or it’s
replacement) as it moves in and out

The Maslow controller board is limited to 2A per motor (and even that is pushing
it), so if you use a bigger DC motor, you will need to modify/replace the
controller board.