Anyone have any idea what might be causing this?

[BeeAmaker]

Anyone have any idea what might be causing this?

This is the 4th time this has happened in the exact same spot. Yesterday it happened once, the second attempt was successful. Last night I changed the file just a bit, re-sliced and now today I can not get a good print. I have a feeling it is "snagging" on the points of the HEX cut out on the front.As the print nears the top of the hex shape the ends curl up. I think by the time the print returns these curled up points are to hard and it jumps the print head. I'm going to try add a bit to my Z lift and see if that helps.

Anyone have any ideas on how ot keep thin over hangs from curling?

[jimustanguitar]

Every time that layer shifting comes up on the SeeMe forum, people tell them to lube their u-joints and to make sure that they don't have any sticky spots in their range of motion.

I assume that there's a smoking gun to be found, but I haven't come across that problem on my own yet.

[BeeAmaker]

I don't think so, movement is free 360. If it happened at random places on the print, maybe. But this is in the exact same point in the print. I'm pretty sure it is catching that hard plastic curl-up from those overhangs, forcing the print head to jump over when it snags it. I'm making some alterations and will try again.

Just to note, the previous 3 that I printed last week does not have that Hex. All 3 printed with no issue.

[BeeAmaker]

My re-design works. no issues, goes past the layer shift point no problem.


These hard little curl points I think are the issues. After looking at the tool path in Repitier, the nozzle moves from the left tip to the right tip to start the next layer. I am 99% sure that the nozzle snags on the now hard plastic curl forcing the head to skip or jump over it thus shifting the next layer over to the right.


I should also point out that I haven't tried z lift yet to see if that will help. I know I have fixed this issue on other prints becasue the nozzle was dragging across the surface by adding Z lift. I'm wondering if the nozzle will still get pushed over if it comes down on top of the hard point instead of dragging into it.

[jimustanguitar]

Looks like you need some cooling fans

[BeeAmaker]

Jan 20, 2016 13:30:41 GMT -5 jimustanguitar said:

Looks like you need some cooling fans

Lol, actually becasue that spot is only about 2.5 mm thick, cooling actually makes it curl worse.
Originally I have fans on the part. When it first occurred I thought it was to much cooling and it became brittle with layer separation so I turned the fans off. But it still happened after that.