So, the ultimaker 2 has a major annoying thing – a teflon spacer that deforms over time due to heat combined with tensile pressure.
So, TFM is becoming a popular replacement, but still has a high end of 255C or so before deformation (that’s okay, but what if we never wanted to replace these?)
Could we experiment with machining a part from a machinable ceramic? Say glass-mica (macor), which has similar friction coefficient, but much better thermal properties. Also, they say it machines with standard metal machining tools, so no diamonds needed…
Regardless, one damn PTFE coupler from ultimaker is like $20.
Dave, for the bit that isolates the hot part from the cold part, you need something with tensile strength, slippery, and, most importantly, heat insulating. If the isolator part were aluminum, it would conduct the heat to readily. Plastic would melt before reaching the nozzle. Pretty much everyone uses PTFE plastic, but it deforms and needs to be replaced.
I do know that ceramic has worked in this application, but I’ve only seen porous plain old vanilla ceramic, which needs firing and isn’t nearly as strong or slick.
Thank you, but I’m trying to stay away from thermoplastics all together. Even though PTFE and PEEK don’t deform under test until above 300+ degrees, they do swell and deform over time due to Tg. The tensile strength also is reduced quickly.
PEEK could be awesome for lowering friction on the colder side, though. It’s good stuff. I may want to buy some off of you.
A ceramic may be really neato, as we’d have a 2000+ degree resistance and would open up consistent use of things like high temp polycarbonate, carbon fiber, various nylons, etc. We can do that now, but the thermoplastics start deforming quickly at print temps above 240C
I have large nozzled bottles for coolant on the lathe. You would just have to squeeze a little bit however work decent for small jobs.
Brad, Lorin
If we want to setup a coolant line and pump im all for helping on that project! Just getting everyone to wipe things down good would be mandatory or death!
Nice, I knew we had the compartment to go with it but couldn’t remember if the pump, lines, strainers came with ours. If it’s something we need I can put it through on metal room budget
I’ll order the Macor when I get a paycheck. A 6" x 1/4" rod is available from morgan ceramics for $19 or less.
I did a temperature study on it and got some decent results and a comparison to PEEK. I didn’t have to do this, but I kinda wanted to see how some of the simulations they moved into Fusion from their pro simulation suite work. Anyway:
Macor part, ultimaker nozzle at 200 degrees:
Macor part nozzle 300 degrees:
Compared to PAEK at 200:
It may increase the pressure slightly due to more thermal conductance and transition, but not in any game changing way.
In other words, very comparable and tolerant of 300 degree+ materials like polycarb.
