400 Steps for a direct drive extruder

[Generic Default]

Hey everyone,

I've been considering getting a drive wheel to put on my spare stepper motor so I can make a direct drive extruder. Right now I have the old Steve's extruder and a greg's geared extruder that I never got working. I'm considering getting a 400 step/revolution stepper motor instead of the standard 200 step/revolution motor because I like to print at lower layer heights (<0.2mm) to get better detail and less blobbing.
The only problem I see that could come up is if the 400 step/rev motor doesn't have enough torque for higher speed retracts compared to the 200 step/rev motor. Of course the 400 stepper has twice the angular resolution which might improve flow rate consistency at small layer heights. Has anyone tried this?

I just want working dual extrusion without issues.

Thanks!

[Eaglezsoar]

Hey everyone,

I've been considering getting a drive wheel to put on my spare stepper motor so I can make a direct drive extruder. Right now I have the old Steve's extruder and a greg's geared extruder that I never got working. I'm considering getting a 400 step/revolution stepper motor instead of the standard 200 step/revolution motor because I like to print at lower layer heights (<0.2mm) to get better detail and less blobbing.
The only problem I see that could come up is if the 400 step/rev motor doesn't have enough torque for higher speed retracts compared to the 200 step/rev motor. Of course the 400 stepper has twice the angular resolution which might improve flow rate consistency at small layer heights. Has anyone tried this?

I just want working dual extrusion without issues.

Thanks!

You say you want dual extrusion without issues but you want to use parts that in themselves introduce issues. I personally do not use dual extruders but those I know that do use standard 200 step motors. The more "non-standard" parts you use the harder it is going to become to troubleshoot problems. If 95% of dual extruder users can get everything to
work fine using 200 steps per revolution then they must be doing something right. To get less blobbing you need to adjust to temperatures, retraction length and speed to the correct
values irregardless of what stepper you are using.

[Polygonhell]

The one thing you need to ensure if you use a 400 step motor, is that at the voltages and speeds used it produces the same or better torque. This unfortunately is more complicated than just looking at the torque rating of the motor.

Personally I doubt you'll get a bit quality win, but it's an interesting experiment if you don't mind the possibility of it failing.

[Lochemage]

It is my understanding that people use the 200 rather than the 400 for direct drive extruders because it provides more torque. If you aren't going to use a wades gear to convert distance into torque, then your motor needs to have enough torque by itself. Also, I doubt that you would be able to see any difference in print quality between the 200 or 400, 200 is more than enough precision, especially if you are using 1.75 filament (which needs more extrusion than 3mm to get the same amount of output plastic).

[Nylocke]

if you use 3mm and you go much further below .1mm layer heights, you might run into issues, otherwise a direct drive 200 steps per rev motor should be pretty good. I know for a fact because I ran an airtrippers 3mm on a RS Mini I made a while back with the same drive gear as the one that SeeMe uses on the MAXes, and it ran perfect at .2mm layer heights, and I could have gone lower and ran perfectly fine

[Jimustanguitar]

Well hi there, old thread.

An interesting note about 400 step motors... Everyone generally talks about using them for motion control at high speeds.

At MRRF, E3D mentioned using a 400 step motor on their new extruder to get more torque out of it at low speeds. I guess that makes sense, because you'd have a "power pulse" where the magnetic poles lined up twice as often.



**edit** got pulled away at lunch between edits. Sorry for the goofy post all afternoon.