I just finished assembling the lead CNC machine with the black box controller. When I move any of the motors at the default speed (something like 189 in/min I think) it stalls and makes a loud sound (see attached video) I have increased the power to the x motor on the side of the black box, but no change. If I slow down the speed it seems to be ok, but then it will miss some during a job. This happens with all three axis. Any thoughts on how to fix this? Thanks Dan
That is pretty fast . What motors are you using? I thought 100 was more of a standard for softer woods and plastics. For aluminum, people keep it around 36 to 40 ipm. Personally, I cut aluminum at about 35 ipm (I use mm so 900mm/min) and wood and plastics at 100 ipm (2500 mm/min). Your acceleration settings may be too high as well. I have the max speed set at 5000mm/min and I upped my acceleration over and over - testing each time - until I found a speed where the CNC stalled I then backed the acceleration off about 10%. I have never had any stalls as of yet.
Great feedback, thanks. I was just moving it from one place to another. I'll try everything with lower speeds tomorrow
Yeah that looks like an acceleration issue, not a speed issue. The motors shouldn't have any issues unloaded at 2500mm/min. Giarc's "dialling" technique works well. Feed rates directly correlate to surface cutting speed, chipload per tooth, etc. You wouldn't use the same feed (machine movement) or speed (~spindle RPM) with a 3/8" polished parabolic 3-flute as a standard 1/16" 2-flute. That's something you have to calculate and enter in CAM. That said, most standard feeds and speeds you find out there are not designed for low-rigidity extrusion machines or high-speed spindles, so make sure you're looking at appropriate sources. Current settings relate more to heat- if you have enough to move the way you want to move without stalling, any more is simply going to start overheating the motor. So careful on how much you increase that.
My extrusion machine is belt, so I can push it to 15,000mm/min. Doesn't help you much though. My mill is dovetail ways and ballscrews (but with closed-loop NEMA 34s), and I have that set at 3500mm/min, I believe.
