Low RPM motor solution... finally!

[absolom7691]

Hey, lumia painters! Thanks to some inspiration from Brian (Laserist) in another lumia thread, I tried out some gear reduced stepper motors that were microstepped using an A4988 driver, set to 16th steps. I was amazed at how smooth the lumia pattern moved when I was running the stepper at about 0.04 RPM. Very smooth. The square wave signal generator I built to pulse the stepper driver will go from 100hz to 3khz. This translates to a variable shaft speed of 0.04 RPM to 1.1 RPM. This is right in the sweet spot for me as this will be powering a double disk lumia that throws a smoke-like pattern at low speed and flowing water pattern at high speed. I have seen other threads talk about steppers for lumia but the consensus was that the motor's "steps" would be visible. With the steppers I found, joined with the A4988 drivers, I could not detect any staccato motion whatsoever, even at a ridiculously slow speed. These are a total win.

The Stepper: https://www.frankhumotor.com/nema-8-...604S-PG64.html And for some reason, the picture on the site is wrong for the stepper and gearbox.

The driver: https://www.amazon.com/HiLetgo-Steps...s%2C163&sr=8-3

These motors have a pretty small footprint, too.

[laserist]

Nice............

[Bradfo69]

Cool! You know... back in the day, I would have ordered 5 motors and 5 drivers already which would then arrive and languish in a box in the storage unit for years because eventually "that day" would come when I laughably believed I was going to build a lumia rig. I show SO much more restraint these days.

[laserist]

only 5? You showed more restraint way back when than I did.

[buffo]

I think he mentioned buying 5 of each only because the Amazon listing is for a set of 5 drivers...

And that also means that he CLICKED the link (just as I did) and seriously considered purchasing them. (Just as I did...)

Adam

[absolom7691]

Bradford and restraint go together like Democrats and Republicans! The other problem he has is that both the angel and devil on his shoulders tell him "Buy it!"

Yeah, the drivers are in sets of 5 but seriously, that's a little over $2 apiece after taxes. Not bad considering the performance. For other applications, I think they can handle up to 4 amps. I think it would be more expensive to buy them individually.

[clickamouse]

Gotta try this.

Thanks…Mike