Good for lumia??

[laserist]

I've done lumia with a stepper, 25:1 gearing, and a < $10 ministeping driver that was smooth as silk even at barely perceptable speeds. (Seriously, you had to stare at in to see see that it was moving at all.) And I'm as critical as hell, ask anybody...

The only problem is - I've got about 40 of the prettest little Olympus brushless DC motors with 1000:1 planetary gear heads that are way better than the Escap motors that we used for Laserium, and I don't need them anymore... sigh

[hakzaw1]

I've done lumia with a stepper, 25:1 gearing, and a < $10 ministeping driver that was smooth as silk even at barely perceptable speeds. (Seriously, you had to stare at in to see see that it was moving at all.) And I'm as critical as hell, ask anybody...

The only problem is - I've got about 40 of the prettest little Olympus brushless DC motors with 1000:1 planetary gear heads that are way better than the Escap motors that we used for Laserium, and I don't need them anymore... sigh

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thank you very much-- these are incredible little motors.. kind of you to give them.
hak

[laserist]

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thank you very much-- these are incredible little motors.. kind of you to give them.
hak

You are welcome.

[clickamouse]

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thank you very much-- these are incredible little motors.. kind of you to give them.
hak

Are there any left?

...Mike

[laserist]

Are there any left?

...Mike

There are, but as BLDC motors you have to build a driver. I sent a couple of driver chips. (I picked them up years ago before they became 750 unit min order qtys, and I have fewer than I have motors. They require 6 external transistors - 2 for each coil and they're surface mount - so bread boarding is tedious.) Speed control can be done badly with input voltage and better by strobeing the driver chip to PWM the drive signal. Doing something close to 0-100% duty cycle requires a dual 555 circuit, or something equally involved. And I suggested he post his experiments...

[clickamouse]

Gotcha, thanks.

...Mike

[absolom7691]

I've done lumia with a stepper, 25:1 gearing, and a < $10 ministeping driver that was smooth as silk even at barely perceptable speeds. (Seriously, you had to stare at in to see see that it was moving at all.) And I'm as critical as hell, ask anybody...

Thanks for the recommend on these. I found some small Nema 8 steppers with a 64:1 planetary gearbox that I just ordered. I'm anxious to try these out with the A4988 drivers I have. I tried some 19:1 steppers and they worked well, very smooth with a microstepping driver. I wanted a slower RPM gearbox since these steppers are noisy at low speed and I need painfully slow speed for my one of my overlapped effects. Now to find some vibration dampers for these nema 8 motors so they don't resonate through the whole lumia!

https://www.frankhumotor.com/nema-8-...604S-PG64.html

[laserist]

I used a 25:1 worm gear to to reduce the speed, and a NEMA 17 stepper driving multiple worm gears. I didn't have any vibration problems in a 30 foot dome. Maybe the flex coupling between the stepper and the drive shaft isolated any vibration.

[absolom7691]

I used a 25:1 worm gear to to reduce the speed, and a NEMA 17 stepper driving multiple worm gears. I didn't have any vibration problems in a 30 foot dome. Maybe the flex coupling between the stepper and the drive shaft isolated any vibration.

I have used NEMA 17 stepper motors before for various projects and used a vibration damper which really took the noise down to practically non existent. I'm hoping to find or fabricate a damper that will work. As for the lumia generated by the 19:1 motors, the image was smooth with no vibration or jitter, the audible noise was fairly loud though. For my living room laser setup, It was noticeable with lower volume music. Dampers have worked well for me in the past. These guys have worked wonders for me with NEMA 17s...

https://a.co/d/37BLfKD