Weird 3D printing issue

[RAGII]

I am having a weird issue where it acts as if the nozzle becomes cold. I have attached a picture of the after math on the latest occurrence. The few times prior the filament went out the other side. The printer continues on like nothing is wrong. The weird part is it is only one one particular model that this happens to. I am printing "shark fins" for quads. The one the fails has a square base, the one that prints has an X base. I used exactly the same printer settings (Slic3r Prusa edition) when slicing the models. It also appears to happen at the same spot in the model, just as it is putting the top layer on the base.

Any thoughts?

 

[kilroy07]

Maybe retraction frequency/distance?
Go layer by layer and see if there is something crazy going on right before the problem starts.

For a quick test of slicer issues, rotate the piece 45 degrees in the Z axis and try printing again.
I've had that help with Cura (crazy math errors?...) before I gave it up for Simplify3D.

 

[Chuppster]

Do you hear the extruder making a clicking noise? Like it's trying to extrude but it can't?

 

[RAGII]

You unusual noises. Printer was running along like everything is happy. It keeps feeding filament, just not through the nozzle. One model prints fine, the other produces this mess with the same settings .

 

[Chuppster]

You unusual noises. Printer was running along like everything is happy. It keeps feeding filament, just not through the nozzle. One model prints fine, the other produces this mess with the same settings .

Do you think it's just not feeding enough filament? If you slow down the print speed does that help?

 

[kilroy07]

From the pic I gathered it's jumping track and skipping the nozzle altogether.

I thought maybe a clogged nozzle (from too much/frequent retraction in one location)

 

[sprzout]

Is it this one particular model that you're trying to print, and no other models have this problem? If so, it's something in the gcode/model that's causing it. My dad had an issue with printing a turtle planter; the model had supports modeled in under the stomach of the turtle, but the feet did not have supports modeled in. The model would print about 3-4 mm under the stomach, then move out to start the feet, and the filament wouldn't stick to the plate because it was too far away.

I'm guessing you've got something with the model that's screwed up, and it isn't showing in the slicing software, but it's just some random number somewhere that causes it to go off the rails, perhaps...I've seen some weird stuff like that before with some models out of Thingiverse and MyMini3D Factory. It's rare, but it happens.

 

[Namactual]

One last shot in the dark.

I can't really see whats going on from the pic, but from what others have said, the filament is actually bypassing the nozzle at some point and continues to feed outside the head?

I would see if the slicer you are using has the option to allow "back feed" or "back out" filament and turn it off. I have never seen such an issue, but maybe the way your head/print nozzle is configured there is a gap between the feeder and the nozzle? When it back feeds it may pull it out just enough to jump out of the nozzle?

This is a wild guess at best, but it's just something that came to mind.

 

[RAGII]

This was a self made model that I created in Onshape. It was a "shark fin" with a square base to match up to the Reaper racing Quad. The filament is still in the nozzle and all of the new feeds end up outside of the printer head where there are some openings. I can relieve the tension on the feed unit and re-wind the filament.

I took this model and modified the base to be more of an X vs square. I am going to try and look at the code and see if something turns off heating the nozzle.

 

[kilroy07]

Depending on how you edited the object, you might have flipped the direction of a face. You can try running it through something that checks for errors (I have occasionally used Netfabb, but it's kind of a pain with licensing) I'm sure there are better/others out there.

Have you tried rotating the object 45 degrees and printing?... That might helps us decide if its software vs hardware.