On Sunday 16 August 2020 11:57:31 John Dammeyer wrote: > What type of 3D printer did you buy? A Creality Ender 3 Pro. Quite highly recommended.
> > -----Original Message----- > > From: Gene Heskett [mailto:ghesk...@shentel.net] > > Sent: August-16-20 5:24 AM > > To: emc-users@lists.sourceforge.net > > Subject: Re: [Emc-users] found a harmonic drive set of .stl's on > > thingiverse > > > > On Saturday 15 August 2020 09:05:48 Gene Heskett wrote: > > > Slim chance I might get the rest of the screws I need later today. > > > > I did, almost, get enough screws to put one together & take it for a > > spin. Screw lengths very critical. Works but the motor only has > > enough torque to turn it at over 2.5 amps/coil drive. But that will > > get the motor hot enough to soften the plastic in about 15 minutes > > so I quit at about 5. > > > > Now the 64k$ question is, it is worth building an air cooled shaft > > extension to isolate these from the motor heat? I'll have to think > > on that. I've been thru hell with this printer and anything I need > > is 3-5 weeks away. The whole hot end of it is a pisspoor design, > > leaking hot plastic out thru the nozzles threads. Or anyplace else. > > The si sock on it is dragging on the work as its filled up, now that > > its cooled, with about an eighth of and inch of solidified plastic > > from the leakage. Its also ripped up from the leaking PLA glueing > > it to the hot end, and damaging it during removal. The final fix > > might be a strip of teflon pipe tape on the nozzles threads, but > > that would have to be done to brand new, clean parts I don't have. > > > > > And thats the news from Lake Woebegon. :( I have an inquiry in at PrintedSolid.com for a bullseye hot end conversion kit WITH a new ptfe bowden tube, but being the weekend, no reply as yet. I like that design better than this one whose weak point is the shark bite style connection used at the top of the hot end. No provision to maintain the pressure of the tube against the nozzle, so as the tube twists with the x motions, it gradually cuts the shark fingers into the plastic of the tube, and the pressure and the twisting wears ditches in the tube wall letting it back away from the rear face of the nozzle. That lets hot plastic backup the outside of the tube until it cools and freezes as a big plug trapped between the now retracted end of the tubing and the nozzle. And the ejector motor just sits there skipping steps. There is a possible fix, which consists of cutting a piece of the tubeing off just long enough to fill the space between the shark bite and the nozzle, so I've done that, and placed a teeny steel washer above it, so the rear of the shark bite then traps the tubing against the back of the nozzle, the guy on y-t showing a razor blade being used in a jig, hopefully to get a square cut. Not having a razor blade, or the jig he was using, I cut it about half a mm long and took the hot block with it sticking out to a piece of 320 sandpaper and sanded it flat, reversed the tubing and sanded the other end flat. This left the shark bite about 1/2 turn from tight when it was clamped, which I noticed was turning with the motion halfway thru the next part, so I took the wrench and drove it tight while it was printing, releasing and relocking the shark bite before restarting the next part. But the silicon rubber sock on the hot block is so badly damaged from being filled up by hot plastic coming down past the nozzles threads that its no longer staying in place like it should. And the shark bites grip on the long tube is on only whats inside the shark bite. I don't expect it to last forever before the locking fingers slide off the end of the tube. Hence the query about the bullseye hot end conversion kit. Guessing about half the cost of a new printer. I asked for a meter of the teflon tubing and some spare nozzles since thats a different design. Includes a new cooling fan, mine is rattling its cage as I broke a blade off trying to clear a dust bunny from it while it was running. 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
