I'm totally new into the world of Arduino, and I have been reading and searching a lot, the last week or two. It's a fascinating world of oppertunities.
BUT... I realise I need help with a project. I recently bought an old hand build vibraphone, with a very old fan motor on it. I want to replace that motor, because the original isn't working, and will never be working again.
I want the new motor to:
only run in one direction (clokwise)
control the rpm of the motor with a potentiometer (40-140 rpm), and run REALLY QUIET and accurate
at any speed.
toggle the motor on and off with the same push button
when the motor stops, it stops in the same position every time, so the rotating fans always stops
vertical (the left half of the image)
an LED blinking with BPM matching the motor RPM. It actually need to blink BPM=RPMx2 because the
fan flips twice per RPM. If the LED is on or off when the motor is off, doesn't matter.
I know I need:
an Arduino uno (should be sufficient?)
a stepper motor: Nema17 or Nema23 or ??
a motor driver/controller of somekind (that's a jungle to me)
a 10K pot.
an LED
a push button.
I really hope one or more of you guys would take your time to help me. Mostly with the coding part, and guinding me to the right motor and driver.
What RPM do You need? Stepper motors are not exactly good for speed.
How did the old construction make the valves stop like pictures show?
How many valves do You have?
I need to be able to adjust the speed between approx. 40-140 RPM.
The old motor didn't make the fans stop in vertical position, it just stopped randomly. But to produce the best sound when the motor is off, they need to be in vertical position.
There are two rows = two driveshaft that are belt driven. But they really don't need much torque, they spin really easy.
I would suggest that You use a "normal" DC motor, not a stepper. Using PWM speed can be controlled. Just run, measure/test and set limits in the code.
One way to halt the valves in vertical could be done by using a magnet and very low RPM during last piece of stopping.
Are You imitating a Lesley; known from organs like old Hammonds?
Note by way of interest, the reference to stepper motors. To stop at the vertical position, you use a photo-interrupter. The only problem with a stepper motor is the noise.
My brother in law played among others vibraphone but I didn't know about any "manipulating mechanics" involved.
Yes, steppers are nociy, wining, singing. Use a more silent DC motor, PWM control and electromagnets that can catch the shaft in the wanted position when motor is powered off and slows down.
As far as I understand, from what I have read so far, then if you use the right stepper driver, and uses microsteps, it would reduce the amount of noise from the stepper. Or have I missed something??
And of cause, using some vibration damper made of rubber.
Go ahead and try it! Your pictures give me the impression that the torque needed is small and then steppers can be quite small. In all, quite low cost stuff can be used.
