Project Design Rev2

A project log for Singing Bowl Player

Similar to a record player, this device will instead play Singing Bowls to help promote meditation and calmness.

W. Jason AlticeW. Jason Altice 08/09/2020 at 16:030 Comments

I drastically changed the singing bowl platform. It is looking a lot better and I tried to add everything I learned from the first design fail. I also changed the motor to a right angle geared brushed motor so I can spin the bowl faster. 

I found that I have to spin the bowl at least 30RPMs for the bowl to start singing. The stepper motor I was using (28BYJ-48) had a max RPM of about 15. This was using full stepping, I tried double stepping and there wasn't enough torque to spin the bowl. 

I modified the base to fit the right angle motor because my measurements where not correct, but close.

Sadly, this motor will not work with this design. It is very loud and I can not control it to slow down to 30RPM. I'm using the DRV8833 motor controller . 

Per the data sheet it says I should be using a 5KHz frequency pulse. If I drop the PWM duty cycle to less than 50% the motor stops. I also tried with a separate power supply and it wouldn't work. Slowest I could get the motor was about 60RPMs. Aside from this, the motor is way too loud. So even if I was able to slow it down more I don't think I could use it. Maybe someone out there knows what I might be doing wrong. But as I see it right now, this motor is a no-go. 

I will have to change this back to the stepper motor, which is very quite, and add some gears to get it up to 30RPMS. I'll modify this Rev2 for the stepper motor and gears. If it works, I print out a new Rev3 with final (hopefully) corrections. 

Guess this is what they mean by fail forward.