extruder skipping need help

I have a P3 Steel that was running great with PETG in the past. I'm running smoothieware. I have a bowden setup with a tube that's approximately 380mm. When things were running fine, I had retraction set to 6mm at 150mm a second with the extruder acceleration at 5000mm/s2. The effective retraction at the hotend looks to be between 2mm and 3mm. Like I said, zero problems printing with this setup. I got makergeeks high temp PLA to have some alternate filament options. Since then, the extruder is skipping about 90% of the time and grinding through filament. So 90% of the prints fail. With PLA, I've had retraction anywhere between 1mm and 3mm. it's worked with 3mm and then bombed on 1mm. Now when I try to print the PETG, I get the same skipping problems that did not exist in the past. Even lowering the retraction to 4mm makes no difference. Lowering the retraction speed makes no difference on either filament. I thought the MK8 gear might have been bad, so I replaced that to no effect. I thought the hotend (E3Dv6) may have been the culprit. I redid the thermal compound and replaced the nozzle. No difference. I'm at a loss here why the extruder is failing to push filament. I thought the hotend was jamming, which it looked like with the PLA. Cleaning it out made no difference. The tensioner isn't flattening the filament and doesn't seem to be too tight. I get slight teeth impressions so I know it's grabbing. Is the extruder motor going bad? It gets warm to the touch when printing. But is something causing a loss of torque? Any help or suggestions would be appreciated. I'm wasting time and filament trying to troubleshoot this.

I would think there is PETG filalment left in the hotend, nozzle, throat, that has reduced the flow area. Being PLA prints a lower temperature, thus not allowing PLA extrusion smoothly.

I think some people use separate hotends when switch between pla and petg to avoid this contamination.

pla is generally way easier to print than petg

I'm at my wits end trying to troubleshoot this. It wouldn't be a PLA issue because of PETG because I get the same problem with PETG. It never did this before. I tried to mess with a few things. I messed around with E acceleration, and no change. I messed around with E voltage and no change. I tried to change the E spring tension, and no change (loose did nothing, and various tight settings did the same as above). It extrudes and reverses no problem when not connected to the hotend. Once it starts to flow through the hot end, it is jamming up. I tried a hand test too. I pushed filament by hand and at first it was flowing well then it started to come out the same look as the extruder. What I mean by that is it was nice smooth filament at first and then it looked hollow-isa. Is my hotend messed up? The thermistor is fairly new. The heat block is as new as the thermistor. Since it was only a couple bucks I replaced it when my last thermistor fried. I'm using the new E3Dv6 thermistor cartridge. The funny things is when I run extruder cleaning wired it more or less goes through, so it doesn't seems like there is a jam. Any help would be appreciated.

Do yourself a big favor and buy a bunch of nozzles for your hotend. I was running into the same issue with my Anet A8, extruder kept skipping. I had printed ABS then PLA and the two just don't mix well in the nozzle. You can try cleaning the nozzle in acetone, but I just purchased a set of 10 that I can swap out. I stay away from ABS now, and just print PLA. I have another 3D printer for printing ABS.

Edited 1 time(s). Last edit at 05/25/2017 03:38PM by broy55.

I always like to come back with resolutions if I can. I replaced the hotend fan. That helped a little. It got the PETG to print again. Unfortunately, the PLA continues to jam. So I will be avoiding PLA.