Problem with PLA and/or EZStruder

[dtgriscom]

I have a Rostock MAX v2 (shipped early March this year), and I've been printing fairly successfully with ABS. However, I recently switched to PLA (from Prototype Supply), and it just isn't working. The symptoms are pretty clear: it's as if the filament is too soft and the EZStruder's hobbed gear is grinding through the filament, eventually stripping it. I'm not clear on the cause, though.

When threading the PLA into the EZStruder, I find that there's a significant bind right when it transitions from the guide block to the Bowden tube mount. Disassembling shows the cause: where the metal Bowden tube mount is clamped between the two plastic halves of the guide block, the structure of the top half of the guide block is significantly stronger than the bottom half, so the Bowden tube mount is pushed downwards, causing a misalignment between the filament hole in the assembled guide block and the hole in the Bowden tube mount.

I've tried filing the filament hole in the bottom guide block half, but haven't made any progress (metal file on ductile plastic just pushes the plastic around; a drill pressed down into the channel also didn't work). I'm thinking of adding some sort of spacer or support under the Bowden tube mount, but haven't come up with a good design. I'm also wondering if the EZStruder has been improved since I received the kit. (I'm also wondering what the plastic cover for the EZStruder is for; it just seems to make it harder to clean things.)


Any thoughts or hints? Might I just be running the hotend too cold for PLA?


Thanks,
Dan

[geneb]

I've seen Andy run some PLAs as high as 210C. You might be just too cold. Bump it higher and see what happens.

g.

[rpress]

In my experience PLA is harder than ABS. I had problems with the EZ-Struder slipping and grinding out the filamant. I found that higher temps certainly helped a bit. But what seemed to work the best was a 2mm shim I put under the EZ-Struder spring. This allowed the hobbed gear to bite into the filament better so it didn't start the downward spiral of slipping and grinding.