On Saturday 29 August 2020 06:37:05 andy pugh wrote: > On Sat, 29 Aug 2020 at 05:35, Greg Bernard <marzetti...@gmail.com> wrote: > > Have you considered having the flex gear part printed by one of the > > 3d printing services in nylon? > > Alternatively, here is a redesign of the flex gear designed to be more > compliant (but with the extra walls of the spokes, maybe also > stronger) > > https://a360.co/32Efa4a
Looks as if it might be more flexible where it counts. I'll put PLA back on the printer and give it a try. TPU is being a bitch, and I am half tempted to see if I can jury rig the fixed OEM hot end under the extruder of the MicroSwiss. The fixed OEM version has compression agaist the back of the nozzle which is the only place the filament touches hot metal. The MicroSwiss has a space above the nozzle thats about 1.92 mm in diameter, but its at the top of the hot block inside the heat break and liquid filament can back up and freeze in that nominally 5mm and colder space. It should never be allowed out of the tubing until its in the hot nozzle. When it plugs up, I have to remove the fan, and run the hot block up to 260C and wait 10 minutes for the heat to migrate high enough to unlock the plug and pull it out, with about a 40 lb pull. Otherwise I take it all apart, drill it out with a #50 drill which is 1.75mm in diameter, the chased with a #49 w/o removeing any metal. Thats at least an hours work because of the heating and cooling time involved. None of this is helped by the fact I've not yet found a mm of this TPU that was over 1.75mm with the huge majority in the very low 1.60mm range. Too damned much room for back flow into areas above the hot block where it slowly freezes up. And this was $35 a kg crap rated +-.03mm. So much for advertising truthfullness... :-( The MicroSwiss idea is ok, but that blue PTFE tubing should be coninuous from the ejector to the rear face of the nozzle, with enough compression to seal it solidly to the rear of the nozzle. The compression is assured by cutting and faceing flat, both ends of a piece of the ptfe tubing, but making it 1 or 2 red one's longer than the length from the rear of the shark bite to the nozzle face, then stacking a flat washer about the right size for a 2-56 screw between the top of the tube, and the bottom of a screw-in shark bite, then screwing the shark bite all the way into the heart sink while a piece of filament is in the tube makeing sure the washer remains centered. As is the MicroSwiss is at least 10x more likely to freeze in the heatbreak and clog mid print. Turning up the machine speed, to 300% or so with the idea of feeding cooler filament thru it faster seems to help, but its a tossup as to whether turning up the nozzle temps helps, I had it freeze twice yesterday at 225C. And before that at 205, 210, and 215. I have a new fan and a meter of the good tubing coming, so I am not done messing with this yet. Stay tuned. Thanks Andy. 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
