On Monday 17 August 2020 14:33:02 Chris Albertson wrote: > "TPU" has a wide range of properties depending on the brand. This is > good because you can match it to what you need from very soft to a > kind of hard rubber. It is harder to print and not the best for > Bowden tube printers. It is like trying to push a rubber band dow the > tube. My printer has the filament feed stepper motor mounted on the > hot end. This adds a huge amount a mass to the head but the delay > from pushing filament to a drop coming out the nozel is less. It is a > design trade off. But if you print slow enough it does not matter.
Re-thinking on how to optimize this thing for maximum life of the flexgear. !. I have to make the bearing projection on the bottom of the cup, fit the bearing with a press fit. I've calculated the amount of change in the printers scale settings to do that, and have one about 30% built, as its about 20 hours of wall time to make one. And I have found the "tune" menu, its seems its only visible of a print is in progress, which when thought about, makes sense. Adjusting flow with my sockless hot end gets me motor step skip backwards at 110%, si ts currently running at 108%, but that was only done by raiseing the hot end temp from 205 to 210C. 55C bed once past the first layer, current speed 140% of what cura told it to, and I had to restart it about 5 times to get the first layer to stick, finally adding a brim and reslicing it. If this one fits the bearing, I'll make them, 3 more and call that the final size. Next is determining the bearing carrier size so a dial, watching the cup as its running, and size adjusted for about a 1.55mm movement of the splines in and out as its running. Just enough expansion to get full contact at maximum, and just enough pullin at minimum to let the peaks pass each other. Thats stage 2 of this things optimization, establishing just enough flex to make it work, but no more. Then, and only then, trim the size of the internel spline ring to get the maximum stretch to bring that point into full contact. Placing the bearing carrier size for the amount of flex as the 2nd adjustment then makes the outer ring that last thing to adjust for a more perfect fit. It can work on half the flex designed into the .step file now. Which should give many times the life. As built from the .step file, 20 minutes to a broken flexgear, broke at the wall bottom just above the fillet every time. But a micro-swiss hot end kit with the extruder moved to the x carriage s/b here today, along with some tpu, and thats when I start all over as I am not 100% convinced PLA will take even this reduced flexing on a long term basis. We shall see I guess. Yes, people, I am kicking tires that have not been kicked before in plastic. But I want the fact thats its plastic removed from the top of the failure list. 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
