Thursday, July 29, 2010

Mixed Emotions....

After several nozzle failures I have a design that seems very robust and made several acceptable prints.

But then more trouble...
Most of the PLA prints have decent shells but the infill is spotty at best.  The extrusion seems to just slow and stop then start again. I tried some ABS I had and that seemed to extruded a little better but the layers did not stick.  I think that is a setting issue but I have not tried adjusting that yet.

As far as the PLA goes I have now tried turning up the heat, down the heat, oiling the filament, manual feeding, adjusting the tension on the Wade's extruder, adjusting the current...  But no luck after the initial success.  The one good thing is that the new nozzle design has not fallen apart and seems very strong.

I have some more ABS so I plan to try adjusting the settings and seeing if I can get the ABS to extrude consistently. (Although I hate the smell and the warping issues with ABS, but I will live with them to diagnose my problem.)

1 comment:

  1. I had two nozzles get pushed right out of the PTFE along the lines of your experiences. the first was like a regular one-piece mendel barrel/nozzle but longer, the second used a third party nozzle (and again the total barrel/nozzle length was fairly long). The current one is as close to vanilla mendel as possible - one-piece barrel/nozzle no longer than 32mm, screwed directly into a 15mm deep, 5mm dia hole drilled into the PTFE (here I went for 40mm long PTFE to ensure enough clearance below the carriage and attached a hose clip at the point of the PTFE where the barrel stops).

    I did a lot of pushing, stopping, starting PLA through by hand at various temperatures to settle on a temp where there is just a slow ooze when not extruding. I think with PLA you want a short barrel to minimize the time when it is in the glass phase.