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sizing a 24v power supply for a 2.x laser cutter

PostPosted: Thu Dec 05, 2013 1:06 am
by alan025
The hack.rva build is progressing and now I need to buy a 24V power supply. The question is, how much amperage? We are using the Inventables NEMA 17 steppers (1.7A per phase). The best description I've been able to find for sizing a power supply is from http://www.homemodelenginemachinist.com ... cnc-18304/

Based on that description, and assuming the steppers are "full-winding" motors, the x and y motors would need a total of 1.7A/phase * 1/3 * 2 motors = 1.2 Amps. Adding something for the 3 axis laser interface board, this would indicate that a supply rated at 2 amps would be fine. However, this seems pretty low. Has anyone tried a 24V power supply this small for a 2.x build? If not, what would be a reasonable size?

Thanks,
Alan

Re: sizing a 24v power supply for a 2.x laser cutter

PostPosted: Thu Dec 05, 2013 2:15 pm
by cvoinescu
I know for sure that a 5 A supply is enough for four NEMA17 motors of very similar spec. If I'm not mistaken, Inventables bundle a 4.5 A 24 V power supply with their Shapeoko kit, which has three NEMA17 motors. Using TLAR (that looks about right) electrical engineering, I'd say 2 A is a little low, but 3 A is fine.