Ever since I saw the "impossible" print that Sanjay Mortimer ​ showed off at

Ever since I saw the “impossible” print that @Sanjay_Mortimer1 ​ showed off at MWRRF, I have been determined to get my support material settings just right. I have succeeded on that front, but am having trouble cooling the overhangs of the print. I wasnt around to see it happen, but what I believed happened was the cooling wasn’t sufficient enough for the large overhang angle and was curling up off of the support material. 300 layers later, and my fan mount ran straight into the overhang, ripping off the fan, and leaving a giant spaghetti monster in its place. There are a few ways that I think I could solve the problem. 1: More cooling. The reason I didn’t use more originally is because when I put it too high, it blows on the end of hotend causing it to do a “thermal runaway”. I made a more focused air stream, but even the air blowing off the bed and the top of the part caused the error. So I lowered it to about 80%. (Just enough for the PID settings to handle it) So maybe get a better fan shroud or one of those silicone heat block covers from E3d (when they become available). 2: I could lower the gap between the top of the support and the part, but I already have it set to 1 layer @.2mm layer height in simplify3d. If I make it 0, I have a feeling it won’t come off.

The key to the problem is that long and drastic overhangs are hard to keep from curling up on each successive layer. It eventually compounds the issue. Unfortunately there isn’t a setting in simplify3d to increase cooling for overhangs. (They should add that) They only have it for bridging right now that I know of. Other than that the only way to combat the issue is to make sure it sticks solidly to the support material. That is why I think E3D’s looked so good. They didn’t need the gap between the support and the actual part with the Edge and Scaffold filament combo.

Any thoughts, suggestions, criticisms?

Printed in Natural ABS @ 260° and 70mm/s. 1mm pillar resolution, 50% support density, horizontal offset 0.1mm vertical offset top 1 layer, and bottom 1 layer. Support seems to peel away ok.

That looks Awesome!

Turn off all fan cooling and go slightly slower. (60mm/sec)

Stop using ABS and try Colorfabb XT or nGen. Much less curling in my experience.

@Richard_Horne ​ I will definitely have to try that. I might try an overhang test print beforehand to see how it does with the curling at different speeds as well. Don’t want to waste another 18+ hours.

R 44r e