Unsure of cause, help?

Hey gang!

I just recently received my Taz2, and have been working with it for a little over a week trying to sort out the one issue I’m having. I’m posting this under Hardware because I think it’s a hardware issue, but it’s strange enough that if it’s not, I’m hoping someone can move the thread.

I have a model that I built (http://www.thingiverse.com/thing:110721) and that’s I’ve printed several of on a MakerBot Replicator 1 in PLA at .2mm layers at 190 degrees. They print uniformly awesome on the Makerbot…solid, clean, all the lines sharp and the most important bit (the rails for the lid (http://www.thingiverse.com/thing:110710) are clean and strong. When I print the two pieces, they slide together perfectly.

But not on my Taz. I’m up to about 8 prints of the box, trying a variety of different settings. I’ve tried .1mm layers, .2mm layers, 200 degrees, 190 degrees. The bed seems to be dead level…I don’t have any issue with sticking/peeling, the bottom layer is great. What’s NOT great is the top layer, which is a wreck. The top 10 or so layers are just terrible, stringy. It looks like the very top layer isn’t even printing properly, because you can see into the structure on some of the prints, like the tops layers just aren’t being printed. The top layer is stringy, to the point where the rails of the lid are just loose threads, not even solid.

I’m slicing directly in the newest version of Slic3r, all my settings look right as far as temperature, diameter of filament, etc, and then loading and printing from the SD card. I’m beginning to think this is related to all the PLA difficulty that people are having with the Taz, given that it’s late in the print that things start falling apart…it’s about a 2.5 hour print at .2 layers and 50% fill, which seems pretty short to have that much heat creep, but it very well could be.

If anyone has any thoughts, I’m all ears. It’s driving me batty.


A picture of the resulting print would be really handy to have to see what the issue might be. Off the top of my head, given that your settings seem right, I’d say maybe check the tension of the idler on the extruder, are the screws tightened to the reccommended amount per the manual, is there any stripped filliament in the hobbed bolt chamber that might cause the filliamnet to be stripping on occasion and cause it to lose traction, is the gear on the extruder nema motor itself tight on the shaft with a fully tightened set screw?

It could very well be the heat creap issue as well. I usually print ABS so i haven’t ran into that one yet.

You can see some of the effect on pics here:


The first is the actual print I’m worried about, the Thingiverse one that was linked above. The second and third was of a Budaschnozzle fan duct that just totally fell apart for reason I have no clue about…it was like a quarter of the thing just stopped printing. See the pics for what I mean.

I’m at a loss here, just really have no clue what’s going on. Lulzbot? Help??

Huh, that is wierd. what is especially wierd is that after it starts having problems, one half of the duct continued to print fine, the other had no extrusion at all. if it were heat creap, i would expect the whole thing to plug up at that point. What it looks like you have to me is a condition where for whatever reason the extruder gear is not able to advance the filliamen when the nozzle hits that halfway point. You had a similar issue further down too, but it corrected itself the next layer. I suspect that you are losing traction in that direction because the idler screws on the extruder are too loose, and the momentum of the extruder is causing the hobbed bolt to lose traction for a bit. maybe coupled with some shavings in there? if I were you, I would start with the Nema 17 motor, make sure the small gear is on and set tightly, make sure the motor is coupled to the mount securely, and that the controll wires look intact. I’d then open up the idler chamber to check for any filliament shavings, and clean that out especially well. I’d then re tension the idler to make sure it has good tension and then try again. If it still has issues after that, it has to be controller, nozzle, or heat creap related.

you might also try slowing the print down considerably and watching to see if any of the extruder components aren’t working correctly.

I had a similar issue related to that smaller gear on the nema motor set screw coming loose once on my Ao-100.