What created these Fails?? --> ABS Pop Corn

[hugepanic]

I am currently printing a canopy for a OV-10 RC model.

The forward canopy frame printed pretty well. It was the first "larger" print i did on the RMV2.

The "good" print...

The aft canopy looks similar, but is about 4 times longer. About 240mm in length.

The first print was a pure desaster. Everything started good, but after about 1h it all got messed up.

I assume that one of the belts slipped. The extruder was running diagonal from center to top right.
I will post a video later.

For the second attempt i adjusted the belts and made the model shorter. Result was about the same...

ABS-Pop-Corn

The first version was about 250mm long, so pretty large for the print bed. The loops/raft was ok at the edges.
It looked similar to the picture posted...

Right now i am printing a similar the aft-aft canopy. It has about the size of the (good printed) forward canopy. I have my gopro running for documentation, will report later...


I can just assume that the arms got in such a geometry that something blocked and the belt slipped....

I have no clue what really was the problem.

Any ideas what caused the ABS pop-corn??

[BenTheRighteous]

Do you have zlift/zhop/whatever enabled in your slicer? If not (or if you do and it's not working), it's possible the nozzle is oh-so-slightly catching on one of the perimeters as it does a fast move and knocking things around.

[hugepanic]

Hey,

i guess/hope your advise was correct!!

I set up the z-lift to 1.0mm and repeated the print.
Since i am not in a hurry here i also reduced speed to 40%.

Right now it is about 90% finished...

At the beginning i sometimes heard a noise when the nozzle was rappidly moving right to left. I guess this was when with the original 0.3mm lift things got mixed up...

Thank you very much!
Ensure you come to my place when you are in bavaria to collect a free beer for this advise!

best regards
Me

[BenTheRighteous]

Awesome, glad to hear that it's working for you now!

[dvandamme]

i had very similar results, mostly it was this horrid scraping noise, and id get a good scratch across the raft if it happened, but i printed up a lot of little things, and its obviously caught on an edge and noise dived into the build, putting the z tower out. it eventually kept going but it its X plane orientation was about 20degrees off. i turned it off at this point.
so ive lifted the z lift to 1mm aswell