PLA stops extruding half way

I have an old Thing-O-Matic from Makerbot running Sailfish firmware with acceleration. I've been printing ProtoParadigm PLA at 210F without issues mostly. With acceleration I can get 80mm/s print speed.

I recently got some Monoprice PLA since I was running low. I fed the PLA through for 1 min to push out any remaining PLA from ProtoParadigm. Then the same gcode was used in ReplicatorG at 210F for filament and 80F for print bed to print the same object that previously printed without issues, basically the only change was the filament. After heating up, the print started without issues and it mostly adheres to the bed pretty well. There are some curling on the first layer in the middle, but the edges seems ok and is slightly squished. After the 2nd layer, everything's "flattened" and looks to be ok. But after 7 layers, the extrusion abruptly stops. I tried different objects of similar size and they all exhibit the same exact issue. First layer has some curling in the middle, after 7 layers exactly, extrusion stops. If the temperature was an issue, I would think it would stop at different times instead of always on layer 7?

The spool is above the print head with the filament having a straight shot to the print head. The spool also has ball bearing so it spins freely. Like mentioned earlier, I printed the whole spool of different PLA with this set up without issues. So something is up with Monoprice PLA, but why on layer 7? I do remember having to bump the temp up to 210F for ProtoParadigm PLA to work reliably at 80mm/s. Also once I finish printing, I have to wait til the head cools before I can print the next object. If I print another right after, it won't extrude. Anyone have any idea what's going on?

All filaments are different, sometimes even from the same supplier. PLA has a tendency to allow heat to creep into the heat break and heat sink if you use a lot of retraction or have a less-than-ideal hot end fan configuration, so that may be contributing. After you've checked retraction, for most PLA, 210 is quite hot (and for all PLA, 80 is really hot on the bed).

Thanks for getting back to me. So you think retract is causing it to jam? What is your suggestion? I can try reducing the head temp for starters.

I know the bed it hot for pla, but the ToM defaults to 100. I had reduced it to 80, and was planning on reducing to 60. But it shouldn't affect layer 7 though.

How much retract (and how fast) are you currently using? I'm not familiar with your specific machine but most hot ends don't usually use more than 5mm and E3Ds often experience problems with more than 2.

Retract appears to be at 1mm. I attached a screen shot of the section.

Edited 1 time(s). Last edit at 03/25/2016 11:16PM by rcboosted.