Recently purchased this stepper motor for a project. It's task is to turn a turntable a certain number of degrees accurately and slowly. The issue is that it does not have enough torque to overcome the static friction of the bearings and accurately turn the turntable, let alone turn it with an object on top.
I have been shopping around for a more powerful stepper motor, but haven't seem to have had much luck. Ideally the motor needs to be NEMA 17 to fit the housing that has been made. I have found this motor, but the fact it has a gears has confused me (does it work just the same?). Also I am no electrician, so if I have a 12V 2000mA plug powering two stepper motors one at 350mA and one at 1.7A it is too much current for the plug?
Does anybody know of/has anyone used a reasonably high torque NEMA 17 stepper motor?
Thanks in advance for any advice anyone can give!
EDIT: Just thought I would add that I am running the stepper motors from this EasyDriver so it would have to be bipolar.
The EasyDriver can control the 350mA motor but it won't be able for the 1.7A motor. Even a BigEasydriver might be struggling. A Pololu DRV8825 has a little more capacity.
For your turntable if you just want slow speed a geared motor may be a better choice. However the gearbox will probably introduce backlash which may or may not be important.
You have not said how much torque you need. Have you measured it - even roughly? There is a simple method of estimating torque in Stepper Motor Basics
I have motors like your 350mA motors and I am rather surprised that yours can't rotate a turntable. Is there a lot of friction.
Remember the hold-in torque rating is not the torque the motor can move, that is
found from the graphs on the datasheet. The 350mA motor has a hold-in torque of
about 0.2Nm, but I wouldn't expect it to turn something against 0.2Nm friction.
Hold-in torque is purely the torque a stationary motor starts to slip at.
Having said that your turntable must have quite a lot of friction...
TommiP:
I've driven my NEMA17 with L298N module.. There are some voltage drop issues but torque has been enough for my use..
Apart from the voltage drop issue an L298 does not come with the ability to limit the current in the motor coils which prevents its use with high voltages and stepper motors generally work better with high voltages. Also the L298 does not have a built-in facility for microstepping. And specialized stepper drivers do the calculations for the appropriate coil sequencing which saves a considerable number of Arduino MCU cycles.
Use an L298 if you have one to hand and don't want to spend money on a specialized driver. But if you are starting from scratch I would strongly recommend a specialized stepper driver.
Robin2:
Apart from the voltage drop issue an L298 does not come with the ability to limit the current in the motor coils which prevents its use with high voltages and stepper motors generally work better with high voltages. Also the L298 does not have a built-in facility for microstepping. And specialized stepper drivers do the calculations for the appropriate coil sequencing which saves a considerable number of Arduino MCU cycles.
Use an L298 if you have one to hand and don't want to spend money on a specialized driver. But if you are starting from scratch I would strongly recommend a specialized stepper driver.
...R
I agree, I just had one and I just needed revs.. I forgot that he wanted accurate angles..
You haven't mention the construction of your turntable, so lets assume it's something like a record turntable. If it is, then a nema17 stepper will have plenty of torque if you can belt drive it off to one side.
I recently completed a camera slider using a nema17 stepper from Adafruit, and it has plenty of torque.
I can't stall the shaft with my hand.
I used an Arduino R3 for control, piggy backed with an Adafruit motor shield plugged in on top.
That geared Nema 17 requires 5400 steps per revolution. FYI. Holding torque at the output of the gearbox is over 400 oz-in, so your turntable would have to have a lot of friction to not turn with that.
