Introduction: Tuning the Potentiometers on a Type a Machines Series 1

By Vaibhav Sharma

Even though your Type A Machines Series 1 printer was well tested before being shipped, it's possible that not all of the motors are functioning at peak performance. Stepper drivers with too little or too much current can cause the motors to skip, degrading your print. This can be due to minor fluctuations in electrical output from one location (the factory) to another (your home) and this problem can be easily solved by tuning your potentiometers.

You will rarely have to do it, but its a necessary skill to have.

Step 1: Gather the Essentials

You will first need -

  • Type A Machines Series 1 3D printer
  • 2mm or 5/64In Hex Key
  • Multimeter (not required but recommended)
  • Ceramic screw driver

Your Type A Machines Series 1 3D printer would have come with a ceramic screw driver and a hex key.

Step 2: Setting Up

  1. Remove the cover at the base to reveal the electronics tray, locate the RUMBA.
  2. Locate the Stepper motor drivers
  3. Set your multimeter at 20V
  4. Open your browser
    1. Access up your printer ( http://series1-xxxx.local:5000/ )
    2. Go to the terminal tab
    3. Issue an M17 g-code. (M17: Enables all stepper motors)
    4. Ensure that the stepper motors are enabled when tuning.

Step 3: Tuning the Potentiometers

USING MULTIMETER

Now your goal is to tune the potentiometer on each stepper motor driver to a value of 0.43V for 24V machines and 0.22V for 12V machines. (If printer's serial number is above 1000, then you own a 24V machine.)

In order to do this, place the multimeter's probes as shown in the image and observe the value on the multimeter. Your multimeter should read 0.43V or 0.22V . If it is anything other value, use the ceramic screw driver to turn the potentiometer clockwise or anti-clockwise to increase or decrease the voltage, respectively.

BY-EAR

If you do not have a multimeter, you can also try to tune the potentiometers by-ear

When adjusting the stepper potentiometers, starting at the stop, here's the progression :

  1. no movement - keep adjusting voltage up
  2. some movement, and a high pitched whine. - getting close
  3. the whine stops, and motors move normally - this is the happy place for the stepper drivers!
  4. the motors start clicking, slowly, then faster as you keep increasing - voltage is too high, turn it back down.

Step 4: Verify

For the last time check whether all stepper motors drivers are at 0.43V.

Congratulations. You have tuned your potentiometers.

Step 5: PRECAUTIONS :

  • Stepper motors disengage after a few seconds if left unattended. Issue an M17 command to re-enable them.

  • Be electrically grounded.

  • Avoid static electricity.

  • Only use ceramic screw drivers.