Weird "flyaways"

[jgates 0]

The UM2 worked perfectly for several weeks, and then I had a nozzle clog. It seems to be cleared (atomic and then, ultimately, a hot-end disassembly). The prints are having some gaps, some sticking issues (seem to be solved after going to 70C for bed), and these weird little diagonal staircases coming out of the sides of the prints.

https://www.sugarsync.com/pf/D333436_95042359_6911064

https://www.sugarsync.com/pf/D333436_95042359_6911076

Prints seem to be pretty good (not as good as original) when there are no lifts in the print - big, continuous objects.

Has anyone seen this before?

Thanks in advance!

Josh

[gr5 2,071]

I call that "stringing". Is retraction on? Those are very easy to remove later as they are barely connected. Ultimaker blue is particularly bad with stringing. You can probably get them by lowering temperature to say 200C but you may then get underextrusion - so if for example you are doing 200C and .2mm layers then your top speed should be 20mm/sec. So it might not be worth lowering the temp that much. Try a different filament too if you have it.

[jgates 0]

Thanks for the reply. They're quite a bit more substantial than any stringing that I've had in the past. They need to be sanded/filed off. Retraction is on. I tried a little hotter than 210C, maybe I'll try a little cooler.

Thanks,

jg

[gr5 2,071]

What is happening is once they are created and it is printing a layer above, it does a retraction but there is a slight convexity to the liquid plastic at the base of the nozzle hole. As it passes over the previous "staircase" this touches the liquid plastic and pulls out the tiniest bit more such that the next step on the staircase is moved over a bit. This repeats until it gets long enough that it droops low enough that the nozzle passes over the staircase and doesn't touch it.

Try a different color filament from UM and you should be fine. The light blue tends to be much worse with this than other colors because it is less viscous at 210C than "normal" filaments. Or like I said, lower the temp.

[jgates 0]

The issue's much better after switching to ColorFabb black, so that's good. The temp. didn't seem to make a huge difference, but it's all fairly manageable at this point. ..now if I can just get big prints not to pull up, I'd be all set!

[gr5 2,071]

now if I can just get big prints not to pull up, I'd be all set

Not so hard to do. Advice varies depending on material and printer so please note which printer you have in your profile settings and are we talking about PLA or ABS?

1) 50C minimum bed temp for PLA (you mention 70C - that's fine also).

2) Use brim - this is very very important - that's why it's on the basic settings on the first page. at least 5 passes if it's a large part. Maybe 10 passes.

3) glue - if you just use the glue stick the simplest way you get too much glue.

glue stick, elmers wood glue (my favorite) and hair spray all have some PVA in them. I have tried all 3. All 3 work well for both ABS and PLA. My favorite is Elmers Wood glue mixed with about 10 parts water, 1 part glue in a glass jar, shake well, apply with paint brush, let dry. Actually 50 parts water might be better as I often later squirt with water for the next print and respread with paint brush and the more dilute it gets the stronger it seems to be.