Asa or pc would be great alternatives . Also , sculpt resin for sla printing works well The last option is to make a negative mold and do a forged carbon part :)
Wayne Dalton Sent from my iPhone > On 9/10/2022, at 12:20 PM, Chris Albertson <albertson.ch...@gmail.com> wrote: > > I just realized this part needs to be heat resistant. Then make a mold > and cast the part with a stiff mixture of glass fiber and epoxy. Polish > the inside with paste wax like you'd on on a car. > > You can print a hollow mould or make the part then a plaster mold from the > part. It is a lot of work for just one part. Why not mill it from a > block of aluminum. I would still make all the part bigger and use huge > fillets, less metal to mill away. > >> On Sat, Oct 8, 2022 at 3:39 PM gene heskett <ghesk...@shentel.net> wrote: >> >>> On 10/8/22 13:25, Chris Albertson wrote: >>> I am a big fan of "plain old PLA" The problem is not the plastic you >> are >>> using but the engineering design. The part looks like you are used to >>> designing with metal or wood, where you start with flat stock and screw >>> parts together. If you need good rigidity with 3D prints, then fill >> all >>> the air space around the part with plastic. Use thick skin and 30% or >> more >>> infill. >>> >>> PLA is not "tough" because it is rigid and will not bend. So it breaks >>> like glass. But as long as you do not break it, PLA has the least flex >> I would think that being in close proximity of thehot block, like 2mm away, >> that PLA would soften and bend or stretch at that bar across the bottom of >> the big vent hole. >> >> I've had the hot end mounting bosses break off clean at the surface despite >> their being buried a mm into the surface, but there is room at the >> bottom of >> the boss to expand that, so since the boss is a cylinder that can be >> tapered, >> its now tapered up to 12mm at the bottom and the hole is expanded .1mm >> to ease >> the torque of self threading the screw. I'd already buried a 3mm hex nut >> in the >> back of it. The boss holding the prox switch is hell to clean out the >> hole, so it got >> expanded .1mm to ease inserting the prox switch, which IMO beats the pants >> off a bltouch. >> >> Very poor access to the bottom eccentrics to adjust how tight the >> POM wheels grip the X transport extrusion bar, but I did add a 10mm tall >> fin to >> both edges to stiffen that. So another is now making on the prusa mk3s. >> And the >> Ender checked, Z re-zeroed and restarted as the jerk was too high on the >> Y and >> it lost a few steps about 4 layers up on the last start, so jerk was >> reduced about >> 20%, as was accel, so maybe it might work at 350mm speeds this time. If >> not, a >> 42 volt psu for the Y motor is next, along with a higher voltage driver. >> That motor >> will be hard to source in a stronger version as its a double shaft. >> Drives both ends >> of the x crossbar from one motor. And that is the heavyweight piece in >> this puzzle. >> I'd love to find a carbon fiber sub for that extrusion. Even a square >> with a linear >> rail s/b lighter, but bring a little red wagon full of cash for that. >> >> Actually, I found the bug in cura that is a showstopper for a tronxy >> 400mm cubed >> printer I bought, and it would be far far easier to swap its puny xy >> motors for 1NM >> 3 phasers I already have. Then the precision will be limited by the >> length of the belts >> it uses as its a doofy arrangement where both motors drive both x and y. >> So to move >> in straight y, the motors run in sync but opposite directions, and move >> the same >> direction for a straight x motion. Both belts go over a slew of pulleys, >> and are around >> 9 or 10 feet long. >> >> But the tronxy doesn't use POM wheels, they are all steel, running on >> round steel >> rods set into off center grooves in the extrusion. >> >> So the potential for increased accuracy is there. I put small casters on >> it so its on >> the floor, but so is the tiny little controller display. There's enough >> ribbon cable to >> move it up some so I will, and I'll probably unload the bed from the psu >> in favor of >> an SSR with a line voltage feed. 80C takes it over 10 minutes from room >> temp on >> the tronxy. >> >> The head is quite similar to the enders so another Spider 300C hot end >> will be here >> Sunday, and I've 70 watt heater resistors for that. W/o the bed, the psu >> should >> handle that. The ender psu is handling both, but the bed is slow, 5 to 6 >> minutes, the >> plus model is 350mm square heated. So I heat its bed before hitting the >> 70 watter >> in the hot end. And I've found a better way to calibrate flows, look at >> the infill. Thin >> and puny looking, increase it 5%, thick and lots of sloppiness, reduce >> it to suit, with clean >> infill the target. 690 is recommended for the ldo, and its actually >> about 100 too much. >> I'm currently running at 670, and flow is still being turned down to 85% >> to get nice, but >> fat and clean infill. With jerk lowered to 45, and accel at 3000, accel >> is still too slow, >> taking around a 6 inch move to hit full speed, but its otherwise running >> well for now. >>> >>> The other things I always say is to use compound curves. >> Those are not as easy in openscad. Variations of a cylinder and sphere >> are available as macro's but true beziers take much longer to render, >> after you study up on the library that does that. I haven't gotten that >> familiar with it yet. There also is not that much room to play in. I'm >> modified >> somewhat, the png I sent, and the prusa will have another done in about >> 4 hours. >> I concentrated on stiffening up the left and right edges, where the warpage >> was showing,but there is no real room to get artsie. And since that's >> all flying >> weight, every gram counts. >> >> Thank you for the advice. Take care and stay well, 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, 1940) >> If we desire respect for the law, we must first make the law respectable. >> - Louis D. Brandeis >> Genes Web page >> <https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgeneslinuxbox.net%3A6309%2F&data=05%7C01%7C%7C11cf07887f4f44d9c44c08daa983bc70%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638008680532863883%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=Dnu%2FD9NWmlgqEblJ1wb%2F6DU1NyZBEi6a4hB5f6MLUYc%3D&reserved=0> >> >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=05%7C01%7C%7C11cf07887f4f44d9c44c08daa983bc70%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638008680532863883%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=48gN1x1Lhr2sd0CfJU34syJ4WSue1ELPo7pqLkjWa1k%3D&reserved=0 >> > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=05%7C01%7C%7C11cf07887f4f44d9c44c08daa983bc70%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638008680532863883%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=48gN1x1Lhr2sd0CfJU34syJ4WSue1ELPo7pqLkjWa1k%3D&reserved=0 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
