Which steppers for DIY Ultimaker 2?

So, I've decided to build my own 3d-printer from parts and use Ultimaker 2 as a base (github). I'm not planning to modify the original design too much but some improvements/changes I'd like to make. One is the XY-steppers: I'll use 0.9 deg steppers instead of 1.8 degs. I'm just wondering which ones would be good. I think Ultimaker 2 uses SY42STH38-1684A steppers (link) for x and y and I've thought to replace them with these option1 or these option2. I think both could work but the larger ones would require some modifications to the printer as the space is limited. Also I'm not sure if the specs of either of the steppers are suitable... What do you think? I would really appreciate some help.

Whether or not a particular specification of stepper motor is suitable depends on which electronics you use, and what power supply voltage you use. So please tell us. In the mean time:

- To get high speeds from 0.9deg/step motors (which both of your suggestions are), you need 24V power and compatible electronics.
- Your first suggestion has high inductance AND is 0.9deg/step, so it is not a good match for any common electronics
- Your second suggestion(the 17HM19-2004S) would be an excellent choice if you use Duet WiFi electronics. Also OK for Duet 0.8.5 and Smoothieboard. Less suitable for boards with plug-in drivers because they will struggle to supply enough current without overheating.

Edited 1 time(s). Last edit at 07/28/2016 04:37PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thank you very much!

I'm just in the beginning of my project so I haven't chosen any parts yet - better get parts that are compatible with each other. I've already thought to use a 24V power so it seems I'm on the right track... (Those are widely used at least in 2d-printers so there must be some reason for that, right? ) I was too a bit skeptical about my first suggestion because the inductance seemed very high compared to many steppers used in 3d-printers and, if I'm not wrong, high inductance means lots of heat and slower reactions = not good. Anyway, I'm glad to hear that the second option seems good. I'll probably buy those. I was thinking to use Smoothieboard because many people seem to recommend it and it seems like a very capable board, got to check the Duet (WiFi) also...

Great! Now my 3d-printer is not far from finished. Anyway, I have a further question: would this be a good choice for the z-axis? Would it work well with Smoothie/Duet? I would also appreciate some recommendations for the extruder stepper (I'll be using bowden extruder with 1.75mm filament). Thanks again!

Edited 1 time(s). Last edit at 07/29/2016 02:30AM by harmaasilmä.

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harmaasilmä
Great! Now my 3d-printer is not far from finished. Anyway, I have a further question: would this be a good choice for the z-axis? Would it work well with Smoothie/Duet? I would also appreciate some recommendations for the extruder stepper (I'll be using bowden extruder with 1.75mm filament). Thanks again!

I can't advise you on the mechanics, but in electrical terms that motor is fine for the Duet, Smoothie and most other electronics.

For the extruder, I recommend using a gear ratio of between 3:1 and 5:1 with 1.75mm filament, and a stepper motor with 20 to 30 Ncm holding torque at full current, with a current rating in the range 1.2 to 1.7A (or 1.2 to 2.0A if using the Duet WiFi). I use JK42HS34-1334 motors and an extruder gear ratio of 34:11.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

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dc42
For the extruder, I recommend using a gear ratio of between 3:1 and 5:1 with 1.75mm filament, and a stepper motor with 20 to 30 Ncm holding torque at full current, with a current rating in the range 1.2 to 1.7A (or 1.2 to 2.0A if using the Duet WiFi). I use JK42HS34-1334 motors and an extruder gear ratio of 34:11.

I'm curious, why the suggestion in geared extruder? Just for more torque at lower current with smaller motors? Or was there some other reason I'm not seeing?

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PDBeal

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dc42
For the extruder, I recommend using a gear ratio of between 3:1 and 5:1 with 1.75mm filament, and a stepper motor with 20 to 30 Ncm holding torque at full current, with a current rating in the range 1.2 to 1.7A (or 1.2 to 2.0A if using the Duet WiFi). I use JK42HS34-1334 motors and an extruder gear ratio of 34:11.

I'm curious, why the suggestion in geared extruder? Just for more torque at lower current with smaller motors? Or was there some other reason I'm not seeing?

Because to be sure of getting enough extrusion force with a non-geared extruder, you need a long, heavy Nema 17 motor run close to its rated current. It's not just the absence of gearing, it's also the fact that the hobbed drive element has to be larger, because it has to fit over a 5mm motor shaft, whereas the hobbed insert on a geared extruder typically fits over an M3 screw.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
I can't advise you on the mechanics, but in electrical terms that motor is fine for the Duet, Smoothie and most other electronics.

For the extruder, I recommend using a gear ratio of between 3:1 and 5:1 with 1.75mm filament, and a stepper motor with 20 to 30 Ncm holding torque at full current, with a current rating in the range 1.2 to 1.7A (or 1.2 to 2.0A if using the Duet WiFi). I use JK42HS34-1334 motors and an extruder gear ratio of 34:11.

Well, I'm studying mechanical engineering so I think I'll manage with the mechanics... Anyway, it's great if that trapezoidal stepper fits because I've thought to buy several components from that store. Thanks again!

I found this stepper which I think would be good for the extruder. It has more torque than you suggested (probably just that 'long, heavy Nema 17 motor' you wrote about) but I don't think that is a problem - quite the opposite! Other specs are very similar. What do you think? It would help if I could buy three steppers from the same place and save some shipping costs.

Having too much torque on the extruder stepper motor can be a problem. The reason is that when the nozzle becomes temporarily obstructed, you want the drive motor to skip, rather than the extruder to chew up the filament. That way, when the obstruction is removed, extrusion continues. You can reduce the torque by reducing current. Unfortunately, if you do that with a long motor that has a lot of rotor inertia, then you have to reduce the acceleration, because the reduced torque can't accelerate the rotor so fast.

I had this problem using the motor you linked to in a 5:1 geared extruder.

Have you considered this one: [www.omc-stepperonline.com] ? It's listed on their main site but not on their EU site.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Aah yes, that's true... I don't want to hurt my filaments. Yes, I've noticed stepperonline has more steppers on their main site but the motor will become quite expensive if I order from there. For example that stepper you suggested would be $24.3, shipping cost being more than the value of the product. Also if I order all the steppers from there the order will be bigger than 22 eur ($24,59) which means extra taxes (+24%) and possible customs. Anyway, I found the JK42HS34-1334 stepper from ebay so that might be one option. Don't know about the quality/how correct the specs are, though...

Have you tried contacting the EU site and asking if they can supply the motor you want?

The JK42HS34-1334 is a good motor, I use them in two of my 3:1 geared extruders.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Yeah, I thought about that too - I'll ask them about that stepper. In case that wont work I'll probably buy a JK42HS34-1334 from ebay. Thanks for your help.

I contacted the Stepperonline customer service and they said that 17HS13-1334S steppers won't be available from EU for next two months unless I make a bulk order. They suggested buying from their main site but that would cost me a lot more. So a JK42HS34-1334 from ebay it will be!

Those 17HM19-2004S steppers I will buy from their EU site and I started to think if I should also buy a power supply from there... What kind of power supply should I buy? Stepperonline sells those PSUs used for LED lights (or similar) whereas Ultimaker 2 uses 24V 220W power brick. I'm not sure if 220Ws would be enough - at least I'm going to replace Ultimaker's 25W heater cartridge with 40W one... Also some power brick would be better because it doesn't require making mains connections unlike most LED PSUs. Any recommendations? (This might be a bit off topic but anyway...)

Edited 1 time(s). Last edit at 08/04/2016 03:28AM by harmaasilmä.

I use no-name LED/CCTV PSUs bought on eBay. The photos look identical to the ones on Stepperonline, but the prices are lower.

It's hard to find a power brick with a power rating greater than about 100W. To prevent users from touching the mains terminals, my delta printer has the POSU under the (fixed) bed, see link in my signature to my blog. For the other one, I printed this cover: [www.thingiverse.com].

The PSU rating you need depends on a number of things, in particular on your bed heater power and whether you want to support dual extrusion with 2 extruder heaters.

Unless you want to print high temperature plastics such as nylon, I advise against using a 40W heater with an E3D or similar hot end. In the event of a heater malfunction, a higher powered heater will cause more damage. I use 30W heaters.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks for the tips! Actually, I found a 24V/30A PSU from my local hackerspace - that surely has enough power! It's totally overkill and quite big too so I'll probably buy a more suitable one later... Maybe I could measure the power consumption somehow and get a better idea on how big PSU I'll actually need...

I bought this heated bed - no power rating but the circuit looks exactly like the one in UM2 so it should be similar. I'm going to use just a single extruder for now - I can then make some upgrades later if I happen to want dual extrusion.

Hmm... I have thought to try printing nylon/acetal sometime as they have some nice properties and are good polymers for mechanics. Mostly I'll print just PLA and such, maybe try ABS sometime, so I'll probably leave the 40W heater for now. Safety is my number one priority so better not get carried away with too much power...

And for this post not to be totally off topic, I did buy those XY steppers (17HM19-2004S) from stepperonline and for the extruder a JK42HS34-1334 from ebay. Had to look closely because they also sell JK42HS34-1334A steppers on ebay and those are not the same: a bit more torque but also more resistance and inductance etc. The -A version seems better to me.