So here's whats happened with Prusadollo:
- the original 240W PSU started acting up, I had lowered the voltage to ~12.3V and now PSU cannot keep the voltage stable during load. So the overvolting might've caused some damage. Swapped in a 360W PSU from the old Dollo that I've been planning on upgrading for a while now. Had the design a slightly bigger PSU cover for it.
- redesigned some of the corner pieces and added some 8mm threaded rods inside the frame parts, now it's quite a lot more stable. Probably still lacking a bit in stiffness, butt good enough for now. Need to test a tall print the see if there's any artifacts...

2019-01-05 17.37.11-1.jpg2019-01-05 18.06.48-1.jpg2019-01-17 20.05.49.jpg

- changed stepper drivers to DRV8825 with 1/32 microstepping. They are quite quiet, especially after the Trinamic drivers coil whine. But It seems that there's some problems with slow speeds, probably this problem: http://cabristor.blogspot.com/2015/0...steps.html?m=1. To fix that, I tried the diode hack shown on that page (TL smoother I guess) and lo and behold, it seems to work. At least partially, slow speeds are smooth now. But when the printer slows down from fast moves, it sounds like there's a sudden skipped step, even though the prints are fine. That doesn't happen with A4988 drivers, so not sure if I'm going to continue using DRV8825. The increased resolution (400steps/mm x and y) is tempting... made a box for the diodes, they get somewhat hot.

2019-01-17 20.18.10.jpg2019-01-17 20.18.03.jpg

- also tried printing ABS with 100C bed temp. Result = the bed belt holder came loose, because the bolts underside the bed heated enough to make the PETG bit soft. Shows in print quality quite drastically when belt position can shift ~1mm. So I need to reprint that part with ABS and also attach the belt holder to bed carriage with extra bolts other than those that are in contact with the bed.

Todo is Raspberry pi box and powering it from 12V. Thinking about using 7V 5W zener diodes in parallel so the power draw won't be an issue...