Recomendation of stepper motors…

João Bastos

hello guys.. from what i read i will use the Wantai 42BYGHM810.. i have a question.. for a bowden setup what extruder motor should i use? the same? and for dual Z axis? thanks

Phaedrux

@whosrdaddy said in Recomendation of stepper motors…:

@dc42:

I use those motors in my delta, but I chose them when it had a Duet 085 in it. For the Duet WiFi or Duet Ethernet, I would choose the -2004 version of the same motor instead of the -1684.

Any reason why David?
I also have those 2004 motors on the XY stage on my coreXY, while they work just fine, I found they make more noise (high pitch whine) than my 2.4A 1.8deg Wantai stepper motor I use on the Z-axis.

Interesting. I use the same 2004 motors for XY and Z on my corexy and notice no whine at all and they are set to 1700 current.

OBELIKS

So 17HM19-2004S or Wantai 42BYGHM810 are suitable for cartesian printers also (overkill?)?
Or is there a more suitable ones? Especially with 12V power supply (24V is planned, but not at the moment).

wilriker

@obeliks said in Recomendation of stepper motors…:

So 17HM19-2004S or Wantai 42BYGHM810 are suitable for cartesian printers also (overkill?)?
Or is there a more suitable ones? Especially with 12V power supply (24V is planned, but not at the moment).

I asked myself the same question, especially the overkill part, as I am in the same position.

IIRC, we have both started with an Anet A8, right @OBELIKS?

OBELIKS

Correct, the only difference is that I started with an older one. So the data on Wiki page is supposed be right.
What did you choose for frame? I went with P3Steel Toolson mk2

wilriker

@obeliks I will answer that in another thread (that I am about to start) in the "My Duet controlled machine" category. Don't want to hijack this thread for it.

Regarding these 0.9° motors definitely have a lower "Speed at which torque starts to drop" (EMF Calculator at https://reprapfirmware.org/) then all of my 1.8° candidates. I think I remember that this is normal but not sure on that. Maybe someone could elaborate on this part.

taconite

It seems like a trade-off:
0.9°/step --> higher resolution than 1.8°/step
0.9°/step --> lower speed where the torque drops than 1.8°/step
low inductance --> "less Back-EMF" so higher speed where the torque drops
low inductance --> motor is more expensive

wilriker

Another thing that I found out and cannot explain (and I hijack this thread a little but it is still related): all motors I researched, independent of all specs always have a temperature rise of 80-85°C. What does this number depend on? All they had in common was being Nema 17 but they were different lengths, different torque, different voltage, different current, different inductance, different resistance.

How can this be?

taconite

my suggestion:
different length = different torque
same torque but lower voltage = high current = same power (P=U*I (formula for DC))
same torque but higher voltage = low current = same power
but the temperature they have is because of what heat they can emit and this depends on the surface area --> so they have all the same emitting "factor" per length (thats why the longer motors have the same temperature)

wilriker

@taconite I also thought that this might be a function of power vs. length but here are two particular motors where it does not fit:

https://www.omc-stepperonline.com/nema-17-stepper-motor/nema-17-bipolar-18deg-18ncm-255ozin-07a-29v-42x42x25mm-4-wires-17hs10-0704s.html
Lenght: 25mm
Power: 2.1W
https://www.omc-stepperonline.com/nema-17-stepper-motor/nema-17-bipolar-18deg-13ncm-184ozin-1a-35v-42x42x20mm-4-wires-17hs08-1004s.html
Length: 20mm
Power: 3.5W

As you can see the second motor is shorter but has over 50% more power but they both have a max temperature rise of 80°C. I am clueless here. Also it is always stated that this temperature will be reached at full current in stand-still with both coils fully energized.