3D Printer Upgrade: Stepper Motors

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3D Printer Upgrade: Stepper Motors 

 

Why should I want to upgrade my stepper motors on my 3D Printer ?

  • Consistency/Reliability:
    • More Torque.
    • Less Heat.
    • Less Noise.
  • Speed/Performance:
    • More Torque at higher speed due to Less Inductance (Bigger is not necessary better).
    • Allow to use the full power of your stepper drivers.

Recently, I received 10 stepper motors for the 3D Printer that I am building, those small guys can handle 2.5A and they have a low inductance (more torque at higher speed): Wantai 42BYGHW811. You can buy them easily and directly from the manufacturer.

Follows a photo of 5 of those little guys.
IMG_20171015_093108.jpg

The "Thing" under upgrade

I have a CTC Bizier which is cheap clone of a Makerbot. It has 4 small stepper motors for X,Y and both extruders that can handle about 1.2 A. What happens is the following, when you run it for a few hours both stepper motors for the extruder, and the Y axis are very hot even in a cold weather.

This printer is modified to use 2 bowden extruders instead of the direct ones: the Y stepper motor had to move the weight of 3 stepper motors (both direct drive extruders + the X axis). This early modification improved the quality of the prints. However the Y stepper motor is still very hot. NB: The current of all stepper drivers was already pushed to the maximum which is about 1A: with a super over sized forced air cooling and a 500W PSU instead of the weak 350W. (The machine has more than 1000 hours under this configuration, so it is considered stable).

Follows a photo to show the difference between the small stepper motor and the upgrade:
IMG_20171015_093141.jpg

So I replaced for a first test the stepper motor for one extruder and tada the following results:

  • Stepper Motor is cool as a cucumber: nearly at the room temperature, which is perfect for summer and important if you are using 3d printed parts.
  • Extrusion is more consistent: a bit more torque.
  • Less noise: the stepper motor is far away from its limits.

I pushed the extrusion rate above the limit with the previous stepper motor and the new stepper motor to show an important reliability improvement: when the extrusion rate is pushed above the limit, the additional torque reduces the amount of slack the stepper motor reverses: it reduces the grinding and the risk of clogging: which is very important for the reliability.

Follows a photo of the effect on the filament, you can see there are many kinks in the filament that can block/jam in a few places:

  • At the extruder outlet.
  • Inside any bowden join.
  • Inside the bowden tube.
  • Inside the hotend.

IMG_20171015_091340.jpg

With the new stepper motor, there is not such kinks as you can see on the following photo, and yes the stepper motor was slipping and ticking strongly during this tests (Zoom in to see the traces of the extruder gear on the filament).

IMG_20171015_091436.jpg

I did not perform any firmware or setting changes, I was just interested in the raw and rough part change improvements.

Summary

I wish I had those guys before, it improves the reliability and the quality of the prints.
The cost for the biffy motor is about 10 bucks (for each for 10 pieces, delivered, VAT included): I just remember about a few prints that fails after 10 or 30 hours due to few kinks on the filament: this upgrade is quiet worth it.

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