Take a gander at the part of this extruder head which looks like a chess pawn. It’s the mounting bracket for the hot end and it’s made out of ceramic. [Ed] came up with the idea to use ceramic to mount the hot end when trying to improve the design while keeping it rather simple and easy to assemble. The concept uses the thermal properties of the ceramic to insulate well enough to operate the extruder at higher temperatures without causing other problems.
Where does one get a custom ceramic part anyway? Turns out you can get low volume runs from China much like PCBs. The minimum order was ten units, which was still a leap of faith since he had no way of testing the design in advance. The first run with the new part went quite well, but only for the first layer and then the filament jammed. He’s still not sure why, but overcame the issue by lining the inside of the ceramic with a PTFE tube. This means he now has to use a smaller filament to fit through it. But the quality of the prints he’s getting with 1.75mm stock and the ceramic head are superb.
It may even be possible to print this ceramic part some day. We remember seeing another extruder that can deposit ceramic clay.
Oh, we’ve been sitting on this one for a while.
[Josef Prusa], brainchild behind what is probably the most popular 3D printer, has just unleashed a new hot end that is capable of printing objects in polycarbonate, PEEK, and nylon.
This new hot end is completely made out of stainless steel – there are no plastic parts made out PTFE or PEEK to keep the heat from transferring up to the extruder. Because the Prusa Nozzle can print these plastics, it’s also now possible to print parts for other hot ends such as the J Head and the Budaschnozzle.
We ran into [Prusa] at NYC Maker Faire a few months ago, and he was kind enough to go over the advancements in his new nozzle and new i3 printer. So far, it looks like the lack of a PEEK insulator isn’t doing the new hot end any harm – [Prusa] has left molten plastic in the nozzle for a few hours and nothing bad has come of it.
You can check out the interview below.
Again, thanks to [Prusa] for granting us an interview and providing some free advertising for Hackaday’s hosts for the NYC Maker Faire. Before you complain about the delay in getting this interview out to you, don’t worry; I slapped a few Makerbot stickers on the back of [Prusa]‘s jacket. Everything’s cool.
Imagine if you will for a moment, you’re printing along on your Makerbot clone and all of a sudden your PTFE hot end melts, what are you going to do now? One solution is to mill your own all metal end from a bolt with some careful drilling. Or you could follow [Peter Jansen] who has made his own all metal hot end using the existing extruder. All that’s required is some aluminum sheet and cutting down the nozzle and hat (and fans to help, but technicalities), and you’re in business with no more melted PTFE hot end.