Prusa Mendel build update #6

This past weekend, Brad came over and helped me tweak things on my Prusa Mendel. He immediately noticed a few issues in the prints I had previously made.

I ended up swapping out my PLA bushing X-carriage with an updated Greg’s X-carriage with LM8UUs (soooo smooth now!), with the intergrated belt tensioning system (a pain to install but works great once done).

Also added a cooling fan for the J-Head hotend via the extra heater inputs on my RAMPS 1.4 board (pin 9) so it’s now PWM controllable (you can see it in the video below). This allowed me to add fan high, fan low and fan off buttons to Pronterface and to integrate it into my Slic3r start gcode (M106 S255/S128 for high/low or M107 for off).

Tweaking the Slic3r settings really helped to correct the issues I was having. It really is invaluable having someone that understands how these settings work, look at your prints and be able to tell what settings are off. Every machine is different but there are some things consistent across them all. My biggest problems seemed to be not enough filament being pushed through and some layer print settings being too slow. I figured slowing everything down would help troubleshoot things but when printing with molten PLA, faster is usually better.

We attempted to upgrade my firmware to Marlin (from Sprinter) but had nothing but trouble. The endstops were ignored and the axis weren’t responding to commands in the correct direction. Switched back to Sprinter and everything worked fine again. Will have to investigate this further on the forums as it seems it may be a common problem with RAMPS 1.4 and may have been fixed earlier today.

Using the new Slic3r (version 7.0 was just released), I was able to print this Yoda:

I think it turned out better than the ABS version I printed awhile ago on my Makerbot (although this was printed at 50% the size)…the overhangs weren’t as bad either.

Brad also brought along his prototype Tantillus printer which is now printing:

(the geek keychain is a favorite test print)

He’s still fine tuning the model files and I’m testing them in ABS (his prototype is entirely PLA). More info soon as he get things just right.

UPDATE: Printed a full size Yoda:

Also added one of the 80mm LED light rings I had with just a couple of zip ties to the fan. I had tried to find a decent way to mount it or simply use some LED light strips left over from my install in the MakerBot but this seems to work the best without getting in the way of anything.