Printing problem - Line not continuous

[nicolas-mazo 0]

Good morning everybody,

First I would like to apologize for the title of this topic, it's hard for me to describe this problem with text, but I will post pictures

I wanted to print this :

So the few first printed line would be like this :

So far so good ! But here is the result :

Full resolution here : http://nicolasmazo.com/4.JPG

My gcode is here : http://nicolasmazo.com/GBS.gcode

I print with 3.0 mm PLA, speed 20%, Temperature : 210°, Buildplate 70°, Fan Speed 30%. Have you got any idea of what happened and how to fix it ?

Thanks a lot !!

 

[Nicolinux 252]

I am not sure what this could be. Normally I'd say bed leveling, but the problem is not sonsistent and it recovers on the upper left. It looks like the nozzle scrapes over the already printed layer. Maybe the bed is warped.

Could you take the glass plate out and see if it is completely flat? Also if you have other means to test the flatness of the heated bed - that'd be the next thing to try.

 

[gr5 962]

The upper left corner area is underextruding. The pattern looks like your feeder is skipping backwards. Please verify this the next time you print - when it is printing that area look at the back of the printer and watch the feeder. It probably skips backwards occasionally in that area.

This is by design. The feeder skips backwards when the pressure in the nozzle gets too high. On the Ultimaker Original it didn't do this and the problem was the filament got chewed up and the print completely failed. At least here you just have some underextrusion (not sure which is worse).

Anyway what is the fix? Well why is the nozzle pressure so high?

1) Probably leveling. I would raise the bottom right corner slightly (which lowers the top left) and also maybe lower the other two screws (by a smaller amount). And try again.

2) Also it helps if your first layer is .3mm thick as leveling isn't as critical. This is the default in Cura.

3) Also it might help if you print hotter (no more than 240C - try 240C for first layer) but not much help because there isn't much space for that plastic to go. As you get higher up in the printing the layers should be fine. By the time you get to the 3rd or 4th layer it should be looking good again.

I guess the main advice is to get leveling perfect and make sure bottom layer is at least .3mm thick.

What is your bottom layer thickness in Cura? (initial layer thickness)

What is your layer height for the rest of the part?

How thick is your part in CAD? (how many layers in layer view are for the base of the part?)