Odd, it is showing mostly on the right edges, maybe the stepper on that side is not working well or has a loose pulley? It is not skipped steps if it doesn’t stay messed up. I have not seen a belt stretch that far but maybe, you can run double belts. I have been trying that and it does let me run faster. I am actually thinking it is your stepover are you doing more than 45% kinda looks like it, above 45% and your bit can wander in more dense materials like MDF.
Details? bit diameter, bit type, cut depth, stepover, rpm, spindle type, feedrate, DOC, table size, pulley tooth count, stepper size, stepper current, drivers, driver voltage? It could be any of these things as well.
Drivers and Voltage: Ramps1.4, latest FW from this site
Stepover and Feedrate: the gcode is at home, so I’ll have to look at that again, but for feedrate, I followed the Estlcam guide on this site, and for stepover I used whatever the default was.
Alright, feed-rate is most likely our culprit. Stepover should be 5%.
If you asked me “Axel, what’s the top speed for the lowrider?” I would have said “Like 8-point-something mm/s? Ryan told me one time and I have it in a forum post”. That’s the right answer.
But, when I followed the Estlcam instructions, seems like that’s still directed just at the MPCNC speeds, which lists a fedderate of 15mm/s. I followed OldGuy’s tutorial as well, which is largely based on the Vicious1 blog post.
This is a classic case of “Axel is so smart he won’t double check things, so let’s just go for it”.
The GCode is attached, feel free to critique! Specifically, I would love to know how to speed this up, because the photo I posted was a few hours of cutting, and it was going to take a few more to finish. How long would folks expect this job to take? Sounds like this job should actually run much slower, with the adjusted feed rates.
You shoudl do test cuts. Using other peoples numbers are only a starting point every build is very different. I always move slow but cut deep, some people move fast and cut shallow. The load is about the same but the use of the bit is different. The last mdf cuts I was doing on the lowRider were 9mm/s at 6mm DOC slotting, Meaning both sides of the bit were in contact, very high load. you should be able to cut deeper of faster for 45% stepover.
A 5% step over is only used on 3D finishing passes usually. Your numbers all seem to be a little wonky.
For all cuts I start with a speed I like 8-10mm/s and leave that alone, then if is it a pocket I do an adaptive (peel) cut with a 45% step over. The only actual adjustments I do are depth, the softer the material the deeper I can cut. If you made a slight error some rpm adjusts can usually fix it. Less passes (deeper cuts) are always faster and your bits last longer as more cut surface is used (you don’t just dull the tips).