I print PC on my TAZ Pro and TAZ Workhorse… but those don’t use brass nozzles (hardened steel … I eventually swapped the nozzle on my Workhorse for the E3D “Nozzle X” which is a hardened steel with what they describe as a “poly-phobic” coating (polymers don’t like to stick to it and if any does stick it is fairly easily wiped clean.).
BTW, I print with PolyMaker’s PolyMax PC.
I have never tried a fiber-filled PC. I have heard (but never tested) that materials such as carbon-fiber filled materials don’t work as expected. This is because the fibers aren’t really long continuous strands (as they would be on say… a carbon-fiber molded part which is layers of woven fabric) – so you don’t really get the equivalent strength of a material where fibers are long continuous strands.
I’ve been using the NozzleX throughout my printing experience, and am printing multi-hour sized parts (not 60 minute parts). My problem is wading around the nozzle that must be removed before the part is ruined. My goal is to use my Lulzbot to print production parts in PC as I have done in NylonX (perfectly & easily), by simply walking away and removing the part 3-10 hours after starting, without babysitting every 15 minutes removing wads of material from the moving head before it snags-off and ruins the print. As my most recent demonstration indicates; it doesn’t seem to be a matter of material sticking to the nozzle, as much as it being attracted to heat…It appears to be sticking to the heat source, not metal or surface per say.
The many various parts I’ve printed with fiber filled PC are sufficiently stiff, strong and durable for their required operation, and Fiber Filled PC exceeds all other materials I’ve tried including Nylon, PETG, ABS and polymer combinations there of. These PC production parts don’t warp and they weather well. ‘…They require too much labor and attention during the printing process. This is my production issue.’
Here is my current focus, as result of suggestions and experimentation through the course of this forum thread;
If my hunch is correct, one might postulate that a higher extrusion and bed temperature could promote the bead to remain hotter longer and less likely to be pulled back to the heat source before it welds to previous laminates and glasses hard. If anyone has found this to be true using extrusion temps well above 300c on modified Lulzbots or other machines, they might chime in.
What is your cooling fan speed set to? If you haven’t already, try 0. That will have more effect than a higher bed temperature. If it does have a beneficial effect, I expect you’ll find the ideal fan speed is on the low side. E.g. we print nGen at 1 to 2% fan on our Workhorse. 0% isn’t enough, and 5% or more leads to very poor layer bonding.
PolyMaker, PolyMax PC, the nozzle temp spec 250c … seem a bit low to you…? ?? … what’s it made of? …are you sure? Do they provide a Technical Data Sheet or an Material Safety Data Sheet? I’ve bought PC from China before. You can read my previous posts on this thread about ‘polycarbonate from China’. …not even good enough to print junk.