Took it to the makerspace 2 days ago.

I made it too large... it barely fits in my car. I think a 400mm cubed print volume was a bit ambitious for a prototype.

After about 1.5 hours of manually re-calibrating it from banging it about and adjusting the wrong values, I got some prints.

The new seal is working perfectly with no leakage for ~12 hours of running as of now.

The mixer runs about half the speed it did un-loaded. The mixer speed slider multiplier range was adjusted accordingly.

I took the print head up to 250C for the testing with no ill effects.

Mixing works, and is perfect.

Four of the five filament drives worked. Two needed current tweaking to push. One is running hot at ~50C even with liquid cooling (I think the current adjust, isn't adjusting so my 1.4A stepper is being driven at 2.2A). One sounds like it has a blown mosfet, but still works well enough to push.

One won't grab filament anymore and needs looking at.

We only had a very small amount of black PLA, so on a whim I loaded black ABS (from a newly opened spool, so yes... it was definitely ABS).

It made perfectly blended grey extrusion, was strong, bonded to either ABS/PLA, and I have a makerspace full of witnesses. :)

Yes, I know they are chemically incompatible. Yes, I know that it shouldn't work... but it does...

Temp, set at 220 - worked, but mixer speed audibly decreased when feeding the ABS.

Temp set at 235 - worked.

It bonded well to itself and the bed (eventually), and to straight PLA/ABS as long as the mixed material was in between.

It would not bond to my bed, until the bed was heated with a heat gun and sprayed with hairspray.

It oozed, probably from running the PLA well over-temp.

All the prints are ugly, but for other reasons.. :)

I didn't have a fan hooked up, so the first ones 'melted', probably because I was printing a really small test object at 60mm/s. Slic3r wanted to turn the fan on... it just didn't exist.

The print on the left, the grey is black ABS + white PLA at 30%/70%, then straight ABS, then straight PLA.

When I did rig up a fan, the PWM drive signal was absent from the mosfet (floating input, so guessing not hooked up). When I hooked it up to just always be on, the hotend (with no shielding, directly in the path of a full speed 2.5in server fan) could not get above 210C even with 80w of power. I have live, uncovered connections under there so rigging up some tin was not tried.

I manually turned on the fan during the print on the right, so it started at temperature and fell slowly enough to get one done. The pink is red + white PLA, then white PLA, then black ABS, then red PLA, then as the last layer printed I switched it back to white.

I had some software issues with arc blending/path smoothing (the CNC roots of Machinekit) so all my mid-path sharp corners are round. I discovered it was adjustable via gcode, so I think I have that sorted.

Bonding to the bed was tricky to impossible. After all, it's just a fake marble ceramic floor tile. It worked *much* better after heating it with the heat gun. Making it a real heated bed is happening today.