On Friday 05 June 2020 17:05:45 Chris Albertson wrote: > First off the motor is limited to 3 Nm or whatever. It can not crush > plastic. The worst case a pulley will see is a stalled out drive > motor and after the motor stops it can not pull harder. So maybe "10 > pounds max" is all the part can ever see. > > That said what you want to adjust is the "wall thickness". With a > 0.4 mm nozzle you can make the walls as thick as you like in multiples > of 0.4mm. Cura's default is 0.8mm but I find going to 1.6mm is good > and makes very strong parts. 2.0 mm is over kill. > > Then behind the wall is infill and this can be 10% or even 100% solid. > More is stronger but very little is gained after 40% infill density. > You can double the print time by settig to 80% not little is gained. > The hub is the weak link, not the infill. > > One thing to turn on is "connect infill lines" as this structurally > connects infill to the walls. Also "print alternate extra wall" will > do the same. With this you can use 1.2mm walls and be stronger and > lighter. Do it both ways and look at Preview. 1.2mm wall with those > to settings is best. as it gives you a better designed 1.6mm wall. > > Same applies to "skin" Skin is just a wall that is parallel to the > build plate. going to 1.0mm skin is enough for these small parts. > 1.2mm adds a lot of print time. > > You can specify 5mm walls but the print time goes up and the motor > can't crush a 1.6mm wall. > > I print rings that slip over 24mm steel hubs and my rings are about > 6mm thick so a 1.6mm inside wall and 1.6mm inside wall only leave a > few mm for infill on a 40T pulley and my 30T pulleys come out solid. > > But if you try one of these with a 9mm "D" hole on a motor and try and > test it, the "D" fails and the set screws fail and the 9mm hols become > 9,5mm bt the teeth are like-new. Even with 1.2mm walls the belts > skip teeth and strip hub-hols before the teeth fail. > > As said by everyone ALWAYS look layer by layer at Cura preview. You > can see every line the printer will make. Yes do check the depth of > the wall behind the teeth but the stress at the hub is about 5X > greater. Look in preview that overhangs are supported > > On Fri, Jun 5, 2020 at 5:34 AM Gene Heskett <ghesk...@shentel.net> wrote: > > After doing that one, i took the right post slider loose and > > loosened its fit on the vertical, as I noted there were Z movements > > that weren't making to the other end of the bar. > > > > And raised the tension in the x belt which turned out to be slack > > enough it was just laying on the right end idler pulley. > > > > But before I try another 10 hour print, I'd like to see an improved > > much better filled tooth profile, my guess is that its 10% or less, > > no high strength fill behind what might be called teeth. I'd like > > to see a 100% fill for at least 4mm behind the teeth, but cura isn't > > doing any of that. Those teeth are 100% crushable all the way to > > the bore reinforcement. > > > > And I can't make the 2 part either, this pulley code won't render if > > the shaft is >9.9mm. Question already posted on that. > > And answered, needed to restart openscad. Then I was able to generate the outer plastic's gcode. I left a 1mm hub at flange OD on the bottom so it should have a stout flange. But I'm having adhesion troubles now, pulling the raft loose. But just found a birds nest on the nozzle, warmed it up and removed that and I think I'm ok for a build, maybe 2. Then scuff it up with some 600 grit, its wearing smooth.
But ATM I am running a calibration test build. Couple hours I think. Thanks Chris 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
