Printing problem or filament problem?

[indy3der]

I've had this problem come and then go. It happens under seemingly identical printing conditions and the same X3g files.

Flashforge Creator (wood model)
Hatchbox ABS 1.75mm
230 degC extruder
110 degC glass bed with Kapton
speeds of 50/80 to 65/90 tried

1117142010.jpg

I don't think it's a filament problem, because it's occurred on two separate prints in the same locations. I am however wondering if it is a temperature or speed problem. My other guess is that it is related to the part warping during the print and basically squishing the still soft plastic out the sides.

[3DPBuser]

Well it's definitely height related, so something is changing on certain layers.

[3dkarma]

It's not clear from the picture, but is it every layer where there's more than one colour?

[richardphat]

Are you printing at .2mm and above resolution?

[indy3der]

It's not clear from the picture, but is it every layer where there's more than one colour?

On the middle layer, yes. On the bottom, it was just a 60 degree overhang around the model

[indy3der]

Are you printing at .2mm and above resolution?

This was with 0.3 mm resolution. I had been at 0.27 mm. Maybe that matters? I was considering trying an overnight print running 0.20 mm at much slower speeds of 40/70. My thoughts are that it will allow more time for the plastic to cool and with reduced height resolution, there will be less "goop" to compress. Sound logic? Or is this one of those cases that requires reverse logic?

[GOC]

Question: Does this issue only occur on layers with dual extrusion? I couldn't tell because the whole object isn't captured by the photo.

[Geoff]

I've had this problem come and then go. It happens under seemingly identical printing conditions and the same X3g files.

Flashforge Creator (wood model)
Hatchbox ABS 1.75mm
230 degC extruder
110 degC glass bed with Kapton
speeds of 50/80 to 65/90 tried

1117142010.jpg

I don't think it's a filament problem, because it's occurred on two separate prints in the same locations. I am however wondering if it is a temperature or speed problem. My other guess is that it is related to the part warping during the print and basically squishing the still soft plastic out the sides.

You are not going mad don't worry, this happened to me also when I first started playing with dual extrusion...

I just got my new machine, I was swapping filament colours like mad... in out, in out, in out...

All filament melts at a different point - even ABS versus ABS. See how you print is printing nice... then crap, then nice... it doesn't always flush through properly.. you know what I ended up doing to fix it after losing literally half my hair? got a guitar string and poked it up the holes while the extruders were at about 250c, then loaded new filament for about a minute making sure it was a perfect straight line down into a slinky on the hotbed... no curling off to the sides of the nozzle and forming a blob that falls eventually... thats a bad thing.

I then levelled my bed until the rafts were coming out properly, and not curly in any spots - all perfect flat straight lines. If they are not... level the bed again.

I have the same machine as you... the heatbed goes out alot, so heat the bed - then level. I used to do it cold but learned from this forum hot is a better way to go, and it really is.

If the Green was Good and the black was the only bad print, I would say that filament might be an issue - but no, the green is messed up aswell, so 1. Check belts are tight, level that bloody bed until your fingers fall off, and 2. make sure you flush the old plastic out well.

[richardphat]

Now I check the picture again, I am convinced this has to do with temperature control. Because I had my print botched when the termistor goes off. My firmware did not include self shutdown and kept printing until it finished. The filament extruded was so hot that it damaged the layer underneath.

Geoff, did you have any trouble about thermistor popping in the middle of a print?