(no subject)

Today was fairly frustrating, but in the end productive.

I've been having serious print issues for the last few months. My layers were not stacking properly on top of one another. Some of this I identified as Z axis wobble, and took care of that by switching to LM8UU linear bearings on the X ends. But some serious issues remained. The prints just looked really sloppy.

Today I had a couple of nozzle jams. I really thought those were gone with the switch to only UltiMachine plastic. I decided to do a full hotend teardown, and that seemed to help, but I damaged the threads in the thermal barrier and it fell apart during a print.

In desperation, I pulled out a J-Head (Mk III-B I think) that I had played with a while back but which got really plugged up with some garbage plastic. I disassembled it and cooked and cleaned it. My prints are now WAY WAY better. I think that the MakerGear hotend was very wobbly. I don't know if this is because the groove is a bit wide, or it had suffered from being disassembled too many times and the threads were loose. Probably the latter.

In any case, the thing is printing beautifully now. I'm actually liking the J-Head now, it seems a bit less kludgy than the MG.

I'm also considering going to a 0.5mm nozzle. ISTM that it shoudlnt' matter that much, the nozzle diameter only really affects how narrow a wall can be, not the resolution of the printer, and the wider nozzle should allow for much faster prints.

In addition to the hotend wrangling, I also bumped up to Marlin 1.0RC2, added a fan to the X carriage (including control from the electronics), and installed an optical endstop on the Z axis, after crashing the head due to a wonky switch and getting fed up with that.

I'm still working on getting the heated print bed installed on printer #2. I wanted to use a SMD LED and I know I have some but I can't find them.

I think I'm going to order another J-Head for printer #2.

After a bit more messing about, I have the heated print bed running on printer 2. It's at 12 volts. I had hoped that using aluminum instead of glass would help 12V be more productive, but it's still slow as snails. It took about 20 minutes to reach 60*C. I don't know if it could even reach ABS temps.

I'm going to stick to my recommendation of using an 18v/15A power supply for the heated print bed. Be sure to heat sink the MOSFET, it will not survive driving 300 watts without it.

I also upgraded to Marlin 1.0RC2 and got the SDSL SD card reader working on the 2nd printer (which has Sanguinololu electronics).