NEMA 23 steppers

I assume that a NEMA 23 motor will provide much more torque that a NEMA 17 motor.

What about speed?

Thanks

NEMA 23 just means that the stepper is 2.3 inches across the face plate. In general the rating for most NEMA 23's is better than MOST NEMA 17's. You can find exceptions.

All that said, to answer your question, I would need to know the particular steppers you want to compare and the drivers that you would use with them. I have a mill that has NEMA23s that produce about 10 times (2-10x more torque compared to a standard 3D printing stepper is about normal) more torque than a standard 3D printer stepper. Of course, I have special drivers that can push the needed current.

Practically, you can probably get the same speed, a little more torque, and a lot cooler operation (because you are undercurrenting the stepper) out of a NEMA 23 using a standard Pololu style driver.

What are you trying to design or where do you want to use this?

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ConceptFORGE
Wally, GUS Simpson, LISA Simpson, THOR Simpson, Sextupteron, CoreXZ

Working on a design that will be alittle heavier than most.

Will use one motor on each axis.

Just wondering what I will have to do.

@ntar827: You might be able to use dual NEMA17s or even one depending on your requirements. Bigger doesn't mean better if it isn't really needed. What weight will you be moving around? What is your target speed and acceleration. A rubber band can move a mountain. (just not that far or fast)

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ConceptFORGE
Wally, GUS Simpson, LISA Simpson, THOR Simpson, Sextupteron, CoreXZ

The upgrade to good nema23's isnt expensive and is a good idea if youre designing from scratch. He is exactly right in what he said above.. except the differences are bigger than he made it sound. I have a mill that uses pac sci nema 23 steppers that are around 150 oz/in. Using a standard ramps board and drivers if you put them on the z axis and told it to move down.. it would trash the entire base of your system or rip the steppers off the plate before they quick. That much difference.

If you built a STANDARD prusa i3 and replaced the 17's with those motors you could run the machine MUCH faster and never worry about lost steps (though youd have to reinforce the heck out of the frame to stop vibration).. and you could run straight up dual extruders and not even notice. The 300 oz/in would handle all 3 of those motors etc without even noticing. And... you should be able to find good nema23's for $25-$50 on ebay. Note do not buy round ones.. they should be squarish. It looks like some chinese shops are pumping out garbage steppers and people expect a good strong stepper without checking the numbers and get junk. Honestly though i'd keep extruder motors nema17.. theres no need for that much power or anything close to it. I'd consider replacing the x and y axis motors first.. and the thing is if you do that you'd need to replace the z axis steppers to deal with the new heavier X.

[www.google.co.uk]

sanyo denki = nema 23 data sheets

Just make sure that the NEMA 23s don't require a lot more amperage than the Pololus can output . The TI DRV8825s are a better choice for running bigger motors and only cost like $1 more.

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vulcanrd
Just make sure that the NEMA 23s don't require a lot more amperage than the Pololus can output .

Steppers don't "require" amperage. A stepper designed for 3A works with 0.5A just fine. You won't get the specified toque, of course, but half the torque of a strong motor might be more than full torque of a smaller one. And running steppers at less than the maximum current safely avoids them to get hot, of course.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I was wondering about this too, can anybody suggest a specific cheap Nema23 stepper motor that work well and produce more power on the TI DRV8825 drivers? Like an Nema23 equivalent to the widely used 47 N-cm Wantai 42BYGHW811? Would the Wantai WT57STH115-4204A (425oz-in 4.2A) be good? They cost twice as much though.

Would using a 24V power supply with the Pololus also help with more torque?

Thanks.

Edited 1 time(s). Last edit at 07/15/2014 06:44AM by Dejay.

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Traumflug

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vulcanrd
Just make sure that the NEMA 23s don't require a lot more amperage than the Pololus can output .

Steppers don't "require" amperage. A stepper designed for 3A works with 0.5A just fine. You won't get the specified toque, of course, but half the torque of a strong motor might be more than full torque of a smaller one. And running steppers at less than the maximum current safely avoids them to get hot, of course.

I'm not sure if that can be said for all steppers motors. I had a 4amp nema23 that I was testing and was running rough. It wasn't until I bumped up the current to about 1.5 amps did it start to run smooth. There is detent torque and mass of the rotor that may affect the running of the stepper at very low current. Friction in the bearings?? I don't know, didn't really look into it. I just know it didn't run very well at low current.

Edited 1 time(s). Last edit at 07/16/2014 12:50AM by Jim Fong.

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Jim Fong
I had a 4amp nema23 that I was testing and was running rough. It wasn't until I bumped up the current to about 1.5 amps did it start to run smooth.

Most likely a problem of the stepper driver: [hydraraptor.blogspot.de]

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Jim Fong
There is detent torque and mass of the rotor that may affect the running of the stepper at very low current. Friction in the bearings??

Friction in ball bearings is neglibile. Mass has a role when accelerating, only. Mass of typical carriages is 10 times higher than the rotational mass inside the stepper, though.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

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Traumflug

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Jim Fong
I had a 4amp nema23 that I was testing and was running rough. It wasn't until I bumped up the current to about 1.5 amps did it start to run smooth.

Most likely a problem of the stepper driver: [hydraraptor.blogspot.de]

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Jim Fong
There is detent torque and mass of the rotor that may affect the running of the stepper at very low current. Friction in the bearings??

Friction in ball bearings is neglibile. Mass has a role when accelerating, only. Mass of typical carriages is 10 times higher than the rotational mass inside the stepper, though.

The point I'm getting at is that there is a minimum current that will make a motor move smoothly. Not all steppers motors are made the same. And certainly not all stepper drivers either. Some work much better than others, as you pointed out in your link. For the one I was testing it was about 1.5amps. Telling someone that all nema23 motors will run at .5amps may not be necessary true.

Edited 1 time(s). Last edit at 07/16/2014 09:52AM by Jim Fong.

[store.quintessentialuniversalbuildingdevice.com]

Wow that's a long URL. Please note I have not used the motors nor seen them in person but they are used with the TI DRV8825 apparently with good results although they are not super powerful (like 4.5 times a good NEMA 17). Alternatively what Nicholas said about running two motors on the same axis should work.

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Jim Fong
Telling someone that all nema23 motors will run at .5amps may not be necessary true.

It is. Driver limits are not a motor limit. And running into driver limits gives the same result independent of the size of the motor connected. NEMA17 steppers would behave just the same. Accordingly you can say that a particular driver is not capable of running at low currents, but not point the finger at the stepper motor.

That said, even with some microsteps not taking effect, the motor still moves. A microstep not taking effect is joined with the next one, so you don't even experience overall step losses.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

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Traumflug

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Jim Fong
Telling someone that all nema23 motors will run at .5amps may not be necessary true.

It is. Driver limits are not a motor limit. And running into driver limits gives the same result independent of the size of the motor connected. NEMA17 steppers would behave just the same. Accordingly you can say that a particular driver is not capable of running at low currents, but not point the finger at the stepper motor.

That said, even with some microsteps not taking effect, the motor still moves. A microstep not taking effect is joined with the next one, so you don't even experience overall step losses.

I disagree, when you set your peak current so low and microstepping the motor. Some of the current waveforms are so low that they don't actually move the motor at all. When microstepping you are dividing the peak current into descrete levels depending on what microstepping settings you select. You can see this as the motor doesn't seem to run smooth like it should. With small nema 17 motors your not going to probably see this issue but larger high current nema 23-42 motors you may run into this. I have a huge nema 34 that won't even move if the current is set at .5amps. I have a industrial parker microstepping driver that can be set down to as low as .13 amps. I guess I am wrong then because your telling me that my 4 amp nema23 motor will move if I set the current that low. It's not gonna happen.

Ok so I hooked up my 4.7 amp Vexta stepper motor to my parker E-DC microstepping driver. I thought it was 4amp but nameplate says 4.7 amp. I set the peak current to .5amps. It just sat there and hummed. Ok yep it doesn't move.

Edit: Forgot to say I used a 24volt PS. I think most ramps users use 12volts. When I bump it up to about .7 amps it starts to spin but very rough and stalled out at about 5rpm. It's not until 1.5amps that it starts to really run smooth and spin several hundred rpm. This is just a example. To say all nema23 stepper motors run well at .5amps peak current is a false. I'm using a very good anti-resonance stepper driver and not a inexpensive pololu. I don't want someone to buy just any big 450oz-in nema23 and hook it up to a pololu and expect to to work better than a nema17. Some will, some won't.

Edited 2 time(s). Last edit at 07/17/2014 11:22AM by Jim Fong.

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Jim Fong
Some will, some won't.

As always My NEMA23s work actually better at low currents than the NEMA17s, both specified for 1.5-1.6A.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Ok i guess i will chime in with my findings using nema 23 and nema 17 steppers..I have tried many different combos.. On my machines i was using a tb6560 controller on 24 volts with 290oz nema 23 . I could only get 325ipm in x and y before loosing steps and only 17 ipm with the z before loosing steps.I swapped to a 72 oz nema 17 for the z axis and was able to run 150ipm without loosing steps..Then the next machine i used a 5 axis breakout board with tb6600 stepper drivers running on 24 volts i could get 500ipm in x and y and 20 ipm on the z without loosing steps then i swapped to a 72 oz nema 17 and was able to get 300ipm without loosing steps.I have yet to try it with ramps-pololu drivers as i am pretty sure it will be the same out come..Now i run ramp-pololu 4988 on 12 volts and 72 oz nema 17 that give me 600ipm in x and y and 200ipm in z .i did do a ramps with a tb6600 stepper driver for the z with a 72 oz nema 17 and got over 300 ipm on the z and the power could easily rip a machine apart..so i'm my findings on a screw drive z axis the nema 17 is far better than a nema 23.Llike 20 times better but on belt driven x and y axis the difference is not much except the nema 17 is still faster. The best answer i could come up with is on a bigger motor the windings are alot longer taking more time for the electricity to make it all the way around the winding and with such short steps the nema 17 has a longer time when the circuit is completed and the motor is actually under power..I know it doesn''t make sense i am not saying i totally have the answer why but these are my findings on several machines nothing else changed but the stepper motors themselves.