[wado1971]

Great video and update, Wado! Your machine is awesome and I imagine what many of us will be modelling ours after...

Just a few things I noticed:
1. The cabletrack/cablecarrier/cable chain: Looks like the mounting attachment point on the Z-axis might be low causing it to bow up at the extremes - causing an additional bend point at the cables in the exit of the chain. I believe best design practice is to have cables come in/out parallel at the exit points of the cable track. This is probably fine for the use case, but it also appears that the cable carrier is full of cables, I believe typical design practice is to not exceed 60% occupancy by cross-sectional volume. At a greater than a certain percent fill occupancy, many cables will be pushed in or out from the neutral axis where they will be binding in either compression or tension with each pass leading to abrasion of the cable insulation. You will want to make sure that the cables in the carrier are firmly secured on the stationary side to avoid ratcheting of cables as well. There are also rules for when one should secure cables/tubing on both ends of the cable track, but they escape me right now. In any case, it would be wise to inspect the cables and cable insulation to look for any of this abrasion and adjust accordingly. I have seen numerous cable chain failures in industry, including abrasion through PTFE tubing, ratcheting, link failures, etc. You may already know all this, but I figured I'd share what I could

2. It looks like signal cables and VFD power cables are both running through the cable chain? If you have noise issues down the road, I might inspect here first. Low voltage square wave signals (5V) from your BOB/Mach3 are running in a cable parallel to the VFD cables powering the spindle? These may be even more susceptible to noise than a standard stepper pulse from a stepper driver considering the lower voltage.

Just some thoughts, it's exciting to see it running!

-UA

UA_Iron - thanks for the tips / suggestions on the cable tray. I've been subconsciously ignoring this a bit... looking at your post I realize I must address it. I definitely underestimated the required bend radii of the spindle cable and the amount of wires running thru it. I'll have to replace this little cable tray with something more appropriate. I have plenty of room to double the width (+height) of the cable tray which will give the VFD power some room.... or is it better to have VFD completely separate in it's own tray? - or that's overkill?

BTW - next project is to take your suggestion on changing ratio of the pulleys and get some more speed - I realize I'm not utilizing this design to it's full potential at the moment. I've gone through all the motion calculations in detail and adjusted my goals - In my original setup I based everything on a targeted accuracy I wanted (~3 tenths) and assumed 2 microstep setting of the MDrives, this resulted in a speed reduction ration of 0.66. As you pointed out, I was asking too many RPMs from the steppers and I realized that the motors run much better at ~8 microstepps. So... ratio will change to 1.25, still achieve my accuracy goals due to microstep at 8 (testing will tell), and push the top end rapids/cutting to double what I have now. Pulleys on order - will keep you posted.