1 Topic by PheonixSD3

  • PheonixSD3
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  • Registered: 2014-06-01
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Topic: Replacement Z-Stepper Question

I want to upgrade my z-axis to M3 rod and need some advice on finding a good drop-in replacement stepper.  I've checked out the list of compatible hardware on the wiki and saw the specs for the OEM smart automation motor and the qu-bd motor but the qu-bd motor is sold out.  I'm using a RUMBA with the RepRapDiscount included DRV8825 drivers capable of up to 2A.  Will this motor from pololu be ok?

http://www.pololu.com/product/2267

SD3, RUMBA, 360W power, ABS: Glass bed + Aquanet Extra Super Hold Hairspray, Anti-backlash Z spanner, Repetier Host + Slic3r

2 Reply by Tomek

  • Tomek
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Re: Replacement Z-Stepper Question

That is fine, you don't have to run it at 1.7A which is too close to the limit of A4988 drivers (probably past the limit with cooling.)


This one is frankly a little better since the one you linked is more for a Y-axis or X-axis (low inductance, and lightweight.)

http://www.pololu.com/product/1200

You also can more readily get max power from it, though you should not really need it. Bear in mind the specs are for half-bipolar windings (i.e, unipolar windings), so the inductance might be a little high if you wire it as bipolar though the strength will be twice. Especially if you're running M3 and want a faster Z-axis then you'll want to wire it in unipolar mode.

6-leads,  half-bipolar mode: http://www.linengineering.com/resources … tions.aspx


Bear in mind it's a little big, I'm not sure if that will effect your buildspace. When I upgraded my rod I decided to run my stepper motor through the bottom of the case (made a hole) so I'd have no worries about that and eventually have more of a path to a heated build platform (the Z-motor would be out of the chamber)

3 Reply by PheonixSD3

  • PheonixSD3
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Re: Replacement Z-Stepper Question

Thanks Tomek.  I'm not worried about my buildspace since I'll be mounting this under the frame, adding legs to the frame, and attaching the M3 rod with a shaft coupler.  Sounds about the same as what you mention.  I may need some help when it comes to wiring as unipolar for faster response - researching now.

Ok - just ordered the #1200 stepper.

M3 rod and nuts from mcmaster:
http://www.mcmaster.com/#94185a140/=tt6ti7
http://www.mcmaster.com/#94150a325/=tt6tld

Couplers:
http://cncsuperstore.com/index.php?rout … duct_id=91

Now to print out some legs and stick them on with 3M command strips! (I love those things)

SD3, RUMBA, 360W power, ABS: Glass bed + Aquanet Extra Super Hold Hairspray, Anti-backlash Z spanner, Repetier Host + Slic3r