Post
by Tim » Mon Apr 21, 2014 3:30 am
You're using the V3b extruder, I guess. I was using the earlier version with the ceramic core, and I put the temperature all the way up to 245 to get a decent print with the white PET+. Which would be 265 on the V3b, if you dare to go that high. For the record, I also had the bed temperature up higher than MadeSolid recommended (they said 60C, I put it at 70C). And for the large print I was doing, I got a lot of warping and pulling off the bed until I shut the fan down completely. Otherwise, the fan cools the base and it starts to contract and pulls off the bed. The problem with that, though, is that the lack of a fan messes with the ability to print over support, so I had to keep increasing the density of my support until it was at 100%. Even then, the interface layer between the support and the part looked very much like your photo, with loose filament strands everywhere.
Eventually, I got a decent enough print, pulled most of the loose filaments off the underside where the support was, and then put the whole piece through a methylene chloride vapor polish cycle, and it came out rather well, given the troubles I had printing it.
Check the PET+ thread on the MakerGear Google Group for a picture I posted of the mess I got when I had to leave the room for 30 minutes just as the print got to the top of the supports, then came back to find a fantastic birdsnest mess of filament goop all over the extruder, the printer, the desk, the floor, . . . Fortunately I managed to get it cleaned up with no permanent damage to anything, and it didn't even clog the extruder. Although my extruder has the fabric sleeve, which was so gunked up with plastic that I needed to replace it.
I have also noticed a strong tendency of the white PET+ to adhere to the extruder nozzle. I usually manage to keep it clean by wiping it down with alcohol on a Q-tip, while it's running hot. But give it time and it will be gunked up again. I feel like the nozzle could use a teflon coating or something. . .