Ahh, now this is a problem I had many many times. I kept thinking ‘Now it’s fixed’, only to find it dropped out and it’d drop down cutting through an inch of MDF and into the table it’s sitting on (that DW660 just keeps on cutting through whatever it seems). I even tried scaling it down – which worked at first, but then it seemed to eventually work it’s way out still. The other day I finally scaled it down even more, printed in ABS this time, then used super glue (which is why I used ABS). I initially had the same problem of it feeling uneven in torque required to move it too – but after using some white lithium grease it became smooth enough for the motor to handle that it doesn’t seem to matter.
Personally I also found things went better for me when I changed the speed and acceleration settings, it seems you can go faster than the default speeds, you just need it to accelerate into it slower, here’s what I’ve been using:
“M203 X75 Y75 Z15 E45”
“M201 X30 Y30 Z4”
The X/Y could probably go faster, but the Z is the biggest difference for me because I seem to gravitate to 3D designs, and the slow Z limit of 5 on the stock firmware was really slowing things down for me. Note: You’ll need to change the microstepping before changing Z to above 10mm/s, the Arduino CPU can’t do more than about 40,000 steps per second, and at 1/32 microstepping that means you’re maxxing out the CPU at only 10mm/s.
Also, I just learned about this, and haven’t had time to try it, but for bit changes you can do M84 S0 to keep the motors on. If you’ve ever had it turn the motors off in the middle of you changing a bit you know what that’s like.