I haven't used PETG, but I'd print that part with 5 outer layers (looks like you're using 12-15) and 20% infill (50% maximum). It'll print faster and it'll probably be stronger in many respects. An FDM printer lays down strands of hot plastic that squish into each other. If a part is printed as a solid, it'll contract when it cools and there will be so much internal stress that the part can tear itself apart. That's usually seen as layer separation, particularly when using high shrinkage materials such as ABS, but most people don't print with as many outer layers as you're using. You may be experiencing layer separation in the X and Y directions instead of the Z direction.
I'm not saying that's the problem you're experiencing, but I think reducing internal stress would be a good start in the right direction. That's one of the things I like about MSLA resin printers. I can print completely solid hard polyurethane objects without concerns over internal stresses, and with no interlayer bonding weaknesses as we have with FDM printing. Resin printers make more heterogeneous parts that are very strong in all directions. -----Original Message----- > From: Gene Heskett [mailto:[email protected]] > Sent: November-12-20 9:02 AM > To: Enhanced Machine Controller (EMC) > Subject: [Emc-users] More questions for the 3d 'spurts > > 2 scans attached if they get thru the listserver. > > I am having a problem with this part, printed right side up, I am getting > this from PETG at 250C nozzle/70C bed. The ledge in the center, > destroyed as you can see, has an overhang of about 1.5mm to retain the > bearing. Turned over, its destroying the bottoms of the cap screw > counterbores. And the supports in the bolt holes are being caught and > pulled back out of the holes, mucking up the bottoms of the counterbores > that bolt it all together. > > Suggested fixes? > > Thanks. > > Cheers, Gene Heskett > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
