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 > I must be using the wrong color pallate, the preview doesn't seem all that usefull to me.
I may also replace the z home switch, there is either one hell of a lot of temp comp needed or its flaky, with a repeatability in the 30 thou range. Similar switches on my go704 have a repeatability in the sub .001 range. 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
