More speed!

Post date: Apr 21, 2013 3:22:49 AM

One of the worse aspects of my mill has been how slow it is. Part of that is that the machine running it is a Pentium 4, and LinuxCNC does software step generation. In short, the machine can't handle driving things too quickly. Up until now I've been stuck at 12 in/min. I've been milling slower than that, so shouldn't be a major concern... except that pcb2gcode (which I use for converting my Gerber files to GCode) isn't the most efficient in the paths it generates, so there are more rapid moves across the board than I would like. Still not a major concern, but a tad irksome.

Now that I've updated the machine a bit (most relevantly better alignment of the leadscrews), I thought I'd see if I could go a little faster... as it turns out, I can: up to 18 in/min (in X and Y; the Z axis is pretty stiff, and didn't run reliably any faster than it was). I think the bigger deal is that I could bump the acceleration up as well. It had been set at 1 in/s², which was quite slow, especially when milling things like round pads. I tested up to 30 in/s² and had no issues, then dropped it back down to 20 in/s² to be safe.

So a little bit of experimentation and I've got a 50% increase in travel speed and a 20x improvement in acceleration. Not too bad!