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PC-CF CarbonX

Posted: Tue Nov 26, 2019 8:21 pm
by crimsonyoshi
Hey everyone! After a bit of a hiatus from the forums this summer - I'm back in action! I've had a whirlwind of activity from some of the projects I've been working on. But I digress - that's not the point of this thread.

I'm going to use this to chronicle my learning experiences with a new plastic I've yet to play with - CarbonX's Polycarbonate infused with Carbon Fiber (CarbonX PC-CF). From all the initial commentary I've received (and there's not a lot of it) I'll be starting with my earlier Polymaker PC and Polymaker's PolySupport settings as posted earlier on this forum. Nozzle temp for PC-CF will be dialed up slightly, and print speed plus layer height likely tweaked a bit as well. A hardened nozzle is en route to me (0.4mm and 0.6mm) as brass won't cut it for PC-CF.

As always, if I have success I'll post my printer settings here! Wish me luck - and if anyone has worked with this stuff before, feel free to drop pointers, tips and tricks. I expect to start working with this material towards Christmas or as late as early January.

Re: PC-CF CarbonX

Posted: Mon Dec 09, 2019 4:38 pm
by crimsonyoshi
And we're off to the races! The unfortunate side effect though is the horse I'm on didn't get enough time with the salt lick! Euphemisms aside, I've initially run into a problem right off the bat which took me a day to scratch my head over before figuring it out.

PC and by extension PC+CF requires a very high extrusion temperature. What's more it requires a very high chamber temperature to really cut down on warping (and we're talking 5 layers high = significant warping to impact your nozzles if your model is more than an inch or two along the X-Y axis). As such, you've got to print this stuff with the lid on and print area fully enclosed. You also want a warm room (or some form of insulation or external heater - mind the fire hazard side of it) and a VERY warm print bed. Dialing the bed up to 110ºC significantly cuts down on the warping issue, but the new problem is PolySupport itself. When temperatures in the chamber start getting high, Polysupport will begin to expand, and the current problem is the filament is expanding between the feeder gear and the nozzle ever so slightly, it's getting stuck.

Temperatures up there are definitely hot enough to slowly burn your fingers if you touch the extrusion apparatus (note not the extruders themselves, but the filament monitor area and the feeder gear area), and those temperatures are high enough to pre-expand Polysupport so it can't be pushed through anymore. I'm finding that happens around 2-3 hours into a print job (room temp is about 23-24ºC currently).

So that throws a monkey wrench into these two materials working together. I'm currently experimenting still using Polysupport for raft material, as well as support material prior to any PC+CF going down. It's 100% doable to tell the printer to set the bed temp to 60 degrees for the raft and support structures, and then switch over to 110 degrees prior to putting any layers of PC+CF material down. Based on prior prints of lower temperatures, this should work. However if your switching nozzles per layer, you need to have a high bed temp to cut down on warping, or find some way to cool the printer feeder below ambient chamber temperatures for Polysupport to not expand prematurely. I almost want to put a water cooler loop on the filament feeder, but I'm not quite at that point yet!