I’ve spent the last month of weekends working on various mods of my Chinese red/black 100W 700x500mm system. A couple of warnings and observations.
a) I’m surprised I haven’t been electrocuted or something in the machine hasn’t exploded before now. Not quite literally, but, “If I’d known then what I know now, I would have spent a LOT more prep time on it.”
b) 100% PSU was 32ma. 2ma higher than the rated max for the tube and 4ma higher than the long-term max.
c) Mains wiring is American-ized Europe; both the hot and neutral go through the main power, E-stop, and laser-enable switches. Switched neutral is … not great … for electrical safety.
d) Crimps on the mains power wires… suck. Two came off as I was re-routing/re-arranging.
e) Mains power looks like it’s about 20ga, max. Ideally should be at least 16ga.
f) The high voltage wire coming from the PSU had been pinched at some point and the jacket had been abraded down to the inner core.
g) The water connections to the laser tube, hidden in the chassis extension, had a slow leak. I had a minor puddle of water come out when I removed the extension.
h) the water outlet tube on the laser tube went to a hole offset from the tube by about 2". There was a significant kink in the hose. I moved the tube out of the way and drilled a hole directly under the outlet so it would feed straight.
i) mains and low-voltage wires are run along the same path. I managed to mostly separate mains and low-voltage runs.
j) Many of the bulkhead passthroughs (cutouts for the wire to get from point A to point B) have no grommet or other protection from abrasion.
k) and just as a general observation, upgrading from analog stepper drivers to digital (DM542T), with a separate 48v power supply, seemed to make the overall mechanical movement much happier and smoother. I ended up at 3200 steps/rev (~18um step) and enabled the half-power idle switch.
These are observations on my own particular machine, but if you get the urge to poke around, these are things to take a look at.