NEMA-17 Stepper Motor High Speed Issue
Hello,
My friend wants me to build him a phonograph.
He has already built the record turntable bracket and drive pulley to connect it to the NEMA-17 stepper motor ( https://www.oyostepper.es/category-6-b0-Motor-paso-a-paso-NEMA-17.html ), so I need to write the corresponding code.
He wants to achieve 4,920,663 rpm in the phonograph's 33,333 rpm mode and 66,428 rpm in the 45 rpm mode. These speeds are common for phonographs, but the problem is I'm unsure if the NEMA-17 motor can reach these speeds. I've tried many methods, including using and not using the AccelStepper library, and even consulted ChatGPT and tried his code version, but none of them seem to work for me.
Does anyone know how to solve this problem? Do I need to adjust the gear ratio of the drive pulley? Or is there a problem with the code? I can provide the code if needed.
RE: NEMA-17 Stepper Motor High Speed Issue
I have never heard of a record player where the turntable is driven by a stepper motor. It will be very hard to get a movement which is entirely free from the vibrations introduced by the motor's steps or micro-steps.
Aside from that general concern: Could you restate your target speeds please? Is that "4,920,663 RPM" as in "nearly 5 million RPM" ?! Or is it 4.920663, i.e. "a bit less than 5"? And how many of those digits are significant -- i.e. to what precision do you need to meet the speed target?
RE: NEMA-17 Stepper Motor High Speed Issue
Yeah, stepper motors turn in steps, not a continuous or smooth rotation. Might be a unique sound for a beatbox, but not good for true fidelity.
MK4S/MMU3
Agreed; steppers are not suitable and those speeds are excessive - especially as designed-for-the-job motors are readily available from many sources ranging from £5 to £50 depending on specific requirements. A search for "gramaphone turntable motor" seems to turn up the best selection.
Cheerio,