What is going on here?

[dbleeze 0]

I am trying to print an iPhone dock with a tall narrow support piece. I have printed two different models but am experiencing the same issue on both.

Attempt 1

This was printed on a UM2 with ColorFabb_XT @ 245º nozzle temp and 110% flow. Layer height was 0.1 and print speed is 50 mm/s.

Attempt 2 - slightly different model but same issue

UM2 with ColorFabb_XT @ 240º nozzle temp and 100% flow. Layer height was 0.1 and print speed is 50 mm/s.

You can see there is no issue with the support piece until after the front dock is completed. Once the extruder is only working on the support piece in the back, things go haywire until the support piece reaches a completely vertical section. I do not have a ton of experience with 3D printing but I have never seen this before. Any ideas?

[gr5 1,075]

I'm 90% sure if you slow to 30mm/sec it will make it look much better - certainly if you were printing PLA that would fix what I'm seeing here.

However if that's not enough, XT is not as easy to print as PLA so I don't know exactly what the problem is - I would start by printing cooler - you can mess with this in the TUNE menu while it's printing to see if temp makes a difference - I would try printing half speed in the problem areas and keep lowering the temp by 5C at a time and mark the test part with a sharpie at the layer height where you change temp and/or speed and keep notes in a log (you think you can memorize it until you are at the 10th temperature change). I strongly recommend you print things like this in PLA. It will be stronger and better looking than in XT. XT is a great material but it took me about 100 prints to get really good at PLA. It took me another 30 to get marginally decent with higher glass temp materials like XT, ABS, Nylon. These higher glass temp materials are MUCH trickier but it can be done.

[krys 205]

Hi there,

I have only used XT Clear, but what works for me is 240C and 50mm/s (or 30mm/s on occasion). But because it is clear, I use only 25% fan.

I wonder what would happen if you tried less fan with the XT White.

That said, my gut says go cooler, like @gr5 suggests. But that contradicts my less fan suggestion, so I guess I do not know.

Also, there are other forum posts about XT with working settings, maybe search around a bit? I don't know if any refer to White though.

Anyway, just some thoughts to try. Good luck!

[catohagen 41]

I've been printing in XT for a couple of weeks now, and what I ended up with is

250-255 degrees and no fans at all, pieces end up much prettier.

Also I would print that model with no support and atleast 0.2mm layerheight, parts seems to get stronger with 0.2 layerheight compared to 0.1mm

[gr5 1,075]

These high glass-temp filaments are similar in that too much fan destroys layer adhesion but no fan makes it look like the photo above. The best solution I found (with ABS anyway) is to enclose the printer, bed at glass temp (100C for ABS) and use more fan than if it's not enclosed. At least 30% for ABS. The warmer the air inside, the higher the fan speed can be, the higher the "look quality" yet still maintaining good layer adhesion (strength). PLA is so much easier!!!!! With PLA just crank dat fan!