Why is my CNC slow?


I built my CNC machine from scratch a while back, but I'm just now beginning to use it, and I'm a little disappointed in it's speed. Having no experience with CNC machines, I'm not sure if my expectations are realistic. I've seen a range of speeds on this forum and see that others are happy with similar speeds, yet I just have a feeling I'm doing something wrong and don't want to live with a slow weak machine and then find out after hours of slow results that I have something simple wrong.


I can't even go 40ipm with no load without the stepper motors crapping out. By crapping out, I mean they stop turning and just sit there buzzing. I can run 20ipm with a 1/2 bit cutting 1/2 inches of MDF, but that's so slow it burns the wood (that's partly because the bit is getting dull at this point). I'd like to mill aluminum but any missed steps will waste a lot of time.

I know it's not because of a mechanical misalignments in my machine, because even without the machine bolted up I can stop the screws by hand (when I have Mach3 set to 40ipm).


I've tried the whole range of micro-step settings as well as the current settings on the drivers, but haven't found a sweet spot that gets the performance that I expected. The only thing I can think of is maybe getting a higher voltage supply but this one should be fine as far as I can tell.

Any advice is appreciated!


Here's my setup:
36v 10A power supply
Ethernet SmoothStepper
DB25-1205 breakout
DM542 Fully Digital Stepper Drive
wantai Stepper Motor 57BYGH627 Nema23 270oz-in 3A
Mach3