I am having issues printing with the ColorFabb XT filament. If first starts of very well, good flow and and nice layer placements, but after 5-8 minutes of printing, it stops flowing and the extruder starts skipping. It looks like i starts seizing up in the heatbreak. The nozzle size i use are .40 and temperature I have tried are 235 to 250 degrees. Does anyone have an idea of what I am doing utterly wrong?
Is your cold end fan connected to 12v DIRECTLY is it always on? do you think the fan may be underperforming. what youre experiencing is a jam. not a particle jam. but a jam of the pla sticking where it shouldnt. some people get it to go away with more CFM to make hte cold end colder. some people think seasoning helps. others it never goes away and they move on to a different hotend. the problem is evident in ALL "all metal hotends" another question. bowden? direct? universal? direct has no PTFE lining. ginving more of a chance of sticking. Universal ( to my knowledge) has a ptfe liner SIMILAR to the bowden version except it doesnt go to a bowden setup. and some people forget to install it. and that makes for bad ju ju and bowden is very similar to universal. anyways ptfe in a hotend that can go higher than 240ish get rather dangerous as ptfe starts to "decompose" and is quite silly. yes i know that the ptfe is in the cold end and contacts the heat break. but ill be honest. if it touches the heatbreak it could get to temp. and thats no bueno.
That simply isn't true. Even if the fan fails, the temperature at the top of the heatbreak will lag the heater block temperature by ~100C.
Perhaps when i said get to temp i should have specified a plastic glassing temp and not extruding temp. the PLA or whatever filament could get soft. and deform/kink and with the tight obnoxious tolerances of the e3d it will jam. or with pla liking to stick to SS same thing dont tell me something isnt true when its there
The context for your statement was that PTFE in a hotend that can go above 240C is "silly", because the PTFE is touching the heatbreak and therefore could reach thermal decomposition temperatures. You made no comments about the Tg of PLA. If the fan fails on a hotend, you wouldn't expect it to extrude PLA anyway.
