Flex 65 Filament
Has anybody tried the Flex 65 Shore Filament from E3D ( no brand, I think its originally from Dutch Filaments)? E3D writes 200-220°C, but that is nonsense. Dutch writes 240 - 270, that is more accurate, but I have tremendous problems with corners curling up on a 30 x 30 x 5 mm print (the bottom part of it). I tried dozens of different settings (alternative is throwing the material away ), but the best I managed so far is with 260 (1st) / 250 degrees print temp and 110 for the bed, without cooling fan at 30 mm/sec print speed. At this temperatures, it sticks like crazy to the bed in the middle, but even then the corners curl up a little bit when the top layers of the base plate are printed ( around 4 mm Z).
The material is not sensitive to print settings. I got nearly the same warped result. I tried cool (230°C) and slow (20 mm/s) on a hot (100) bed, very hot (270°C), hot at a cool bed with even with cooling fan and so on. A 5 mm brim helps, but then either the brim rips or it gets very, very hard to remove or even rips the first layer off. If it gets too cool or fast, the interlayer bonding fails. I print at .35 layer height, but that also doesn't make a difference.
The hard rubberlike result is quite handy for some purposes, so I'd really like to know if someone has successfully printed that material. I have the same problem with Taulman Bridge Nylon: Sticks like crazy in the middle, but the corners curling up. PLA and ABS print fine, but there are cases when this aren't the best materials for the part. (And yes, I know that I can buy these pipe plugs cheaper than to make them myself)
Re: Flex 65 Filament
After some tries, it seems that I have solved that problem sufficently, so that I'm able to print that material. Because of its somewhat elastic properties, it makes a good material for protection and shock absorbing.
My settings:
Layer height: 0.2 mm / First layer: 0.35 mm, Z correction -0.02 mm so that the first layer is somewhat squished
3 perimeters, 5 bottom and 6 top layers
! Important ! Brim: 5 mm -> the 0.35 thick brim holds the pieces in place, like other flexibles, the adhesion to the surface is a lot.
Speeds like in the 0.2 mm NORMAL Prusa Slicer Preset
Same for the Extrusion width, with changed first layer width to 0.5 mm
Bed temperature 100°C
Print temperature first layer 245°C, others 255°C
No cooling, no speed reduction
That worked fine for most parts.
Re: Flex 65 Filament
After half a spool of this stuff, i give up. The shrinkage is simply too much and you have either a completely warped bottom or a ripped PEI sheet because if it sticks, it sticks too much. So, I'm going to replace my sheet now and try Fillamentum Flexfill 98, it should have the same elasticity and if Prusa sells it, it should work a lot better or i'm going to be mad.
I just wonder how the powder-coated surface of the new MK3 would react to such a material. I did only small pieces, but NinjaFlex sticks about the same to the surface and there are not so much alternatives if you need a gasket. Not so nice if you damage a much more expensive surface. A PEI sheet is only $8 ...