Recomendation of stepper motors…

peirof · 8 Feb 2018, 06:19

Yes….

I haved read it... but there are some concepts i do not understand, the are:

[[language]]
Inductance
Resistance and rated voltage
Back emf due to rotation

i see clear, the final recomendations:

[[language]]
General recommendations
Unless you will be using external stepper motor drivers, choose motors with rated current of at least 1.2A, and at most 2.0A for the Duet 0.6 and Duet 0.8.5, or 3A for the Duet WiFi or Duet Ethernet.
Plan to run each stepper motor at between 50% and 85% of its rated current.
Size: Nema 17 is the most popular size used in 3D printers. Nema 14 is an alternative in a highly-geared extruder. Use Nema 23 motors if you cannot get sufficient torque from long Nema 17 motors.
Avoid motors with rated voltage (or product of rated current and phase resistance) > 4V or inductance > 4mH.
Choose 0.9deg/step motors where you want extra positioning accuracy, e.g. for the tower motors of a delta printer. Otherwise choose 1.8deg/step motors.
If you use any 0.9deg/step motors, or high torque motors, use 24V power so that you will be able to maintain torque at higher speeds.
If using a highly-geared extruder (for example, an extruder that uses a flexible drive cable to transmit the torque from the motor to a worm reduction gear), use a short low-inductance 1.8deg/step motor to drive it.

So I ask for a recommendation for which engines are the most suitable for a delta, if I am clear, I would like to buy them for 0.9 deg.

I only have doubts in the rest. XD

DjDemonD · 2 Aug 2018, 13:00

Chose a motor with sufficient current handling. Generally in nema 17 size longer motors can handle more current. A Tevo LM is going to be easily driven by a 2A motor which you can nominally run at 1.6A or thereabout using duet (this keeps motor heat build up to manageable levels).

Inductance is the motors abilitiy to act as a generator, as you turn it it generates power which counteracts your voltage being used to turn it, but since they generate low voltages at the sort of speeds 3d printers use, supplying them with 24v (powering your duet from 24v) gives you more overhead. So 24v gives faster speeds for any given motor but faster still for low inductance.

The motors voltage rating is not important.

Select the lowest inductance motor, which is the size and current rating you need to move your axes around. Going over 3A is a bit pointless as the duet can't supply more than 2.6A (approx).

I went for these https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-17-bipolar-09deg-44ncm-623ozin-168a-28v-42x42x47mm-4-wires-17hm19-1684s.html

peirof · 8 Feb 2018, 15:49

@DjDemonD:

Chose a motor with sufficient current handling. Generally in nema 17 size longer motors can handle more current. A Tevo LM is going to be easily driven by a 2A motor which you can nominally run at 1.6A or thereabout using duet (this keeps motor heat build up to manageable levels).

Inductance is the motors abilitiy to act as a generator, as you turn it it generates power which counteracts your voltage being used to turn it, but since they generate low voltages at the sort of speeds 3d printers use, supplying them with 24v (powering your duet from 24v) gives you more overhead. So 24v gives faster speeds for any given motor but faster still for low inductance.

The motors voltage rating is not important.

Select the lowest inductance motor, which is the size and current rating you need to move your axes around. Going over 3A is a bit pointless as the duet can't supply more than 2.6A (approx).

I went for these https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-17-bipolar-09deg-44ncm-623ozin-168a-28v-42x42x47mm-4-wires-17hm19-1684s.html

Perfect, thanks for the link…

dc42 · 8 Feb 2018, 16:01

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.

peirof · 8 Feb 2018, 19:05

these?

https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-17-bipolar-09deg-46ncm-651ozin-2a-28v-42x42x48mm-4-wires-17hm19-2004s.html?search=17HM19-2004S

whosrdaddy · 2 Aug 2018, 19:25

@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.

DjDemonD · 8 Feb 2018, 20:46

I suppose the 2A motor just gives you a bit more torque than the 1.68A which are popular when using plug in drivers as that's about the biggest motor you can reliably drive without overheating the driver.

That being said I can move 400mm/s on my delta with the 1.68A motors.

I do also have some custom made wantai motors on my corexy (they just have dual shaft and are 0.9 deg which they didn't have in stock) and they are nicely made, quiet and accurate.

dc42 · 9 Feb 2018, 08:37

@peirof:

these?

https://www.omc-stepperonline.com/hybrid-stepper-motor/nema-17-bipolar-09deg-46ncm-651ozin-2a-28v-42x42x48mm-4-wires-17hm19-2004s.html?search=17HM19-2004S

Yes, those. They have lower inductance than the 1.68A version, so full torque should be maintained to a higher speed.

MSquared · 10 Feb 2018, 22:06

Just curious what everyones thoughts on the Wantai 42BYGHM810 are? They seem to be almost perfect with the rated current at 2.4A and the inductance at 1.8mH. I feel like I am missing something here because all the other motors I have looked at the inductance is much higher.

Specs / Costs:
http://www.wantmotor.com/product/42byghm.html
https://garagedays3d.com/shop/mechanics/stepper-motor-nema17-wantai-42byghm810/
https://www.aliexpress.com/item/4-lead-Nema17-stepper-motor-42BYGHM810-68oz-in-48mm-2-4A-5mm-shaft-CE-ROHS-ISO/560349599.html
https://www.ebay.com/itm/Wantai-5PCS-Nema17-Stepper-Motor-42BYGHM810-0-9-4200g-cm-48mm-2-4A-3D-Printer-/321350696340

Any feedback / enlightenment would be appreciated…

-M

DjDemonD · 10 Feb 2018, 22:46

That wantai motor looks great, might get some myself.

MSquared · 10 Feb 2018, 23:24

I know right! I already have some motors in route from steppers online but am considering getting these too. One can never have too many steppers….

dc42 · 11 Feb 2018, 08:05

The low inductance of that Wantai motor would make it an excellent choice for a Delta printer.

João Bastos · 11 Jul 2018, 13:48

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 · 11 Jul 2018, 23:49

@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 · 12 Jul 2018, 10:31

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 · 12 Jul 2018, 10:45

@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 · 12 Jul 2018, 10:47

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 · 12 Jul 2018, 10:50

@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 · 12 Jul 2018, 11:18

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 · 12 Jul 2018, 14:29

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?