Go to homepage
6 / 9
Mar 2017

Im building a 3d printer and I bought some 1.7 amp steppers (60 ncm torque) running a a ramps 1.4 and a 12v 350 watt PSU. Current reads at .55 volts.

I can pinch the 5mm motor shaft fairly tight while its in motion and stop it. It seems like it should have a lot more torque than its putting out. Am I wrong, or should I be getting more torque?

  • created

    Mar '17
  • last reply

    Mar '17
  • 8

    replies

  • 4.1k

    views

  • 4

    users

Current is measured in amps not volts and must be measured in series with the power connections.

If you read my post you may have noticed I am running the steppers at basically the maximum amount of current that my stepper drivers can handle.

To easily reference your current flow you can measure the VOLTAGE coming off of the the potentiometer which controls current flow to the motors on the stepper driver.

Well then i’m guessing they are A4988 Drivers, usually they can only push out 1A per phase, so falling short of your motors rated 1.7A. It will still probably operate ok, as long as it prints at the speed you want without losing steps i wouldn’t worry about it. The next thing to do would be to get some DRV8825 or some TMC steppers. The DRV’s will be noisier but the TMC’s can support up to 256x microstepping so would be near silent.

Measure the amps from the pot to find out exactly how much current they are supplying. I know you can measure the volts but measuring the amps is more useful imo.

Sorry, I am mistaken. It’s difficult to see what your issue could be, I use similar “generic” drivers and about 1.7 amp steppers and can stop the motors with my fingers no worries. I would finish your printer build and see how it goes :slight_smile: