Blobs where new layers begin

[stiffmasters]

Hi Everyone,

I'm having a new problem, this has sort of come out of nowhere, I've always had slight blobs when a new layer perimeter begins printing, but it seems to have gotten worse. Does anyone know any appropriate settings in sfact that could maybe get rid of it? Or could it be a hardware issue.

I have checked that my extruder is calibrated and the bed is perfectly level.

Many thanks
Jason

[andrewsi]

This is typically addressed by a) ensuring that the slicer has retraction enabled (suck filament back up when changing layers or making non-print moves), and b) ensure that the settings the slicer uses for retraction are sufficient for the filament and temperature (i.e. its tendency to ooze). Typically you retract at a high E speed, and retract by 2-4mm, and this should significantly reduce your blobs.

[stiffmasters]

Thanks andrewsi,

I've checked those settings and they seem to set properly, I've been printing successfully for 6 months without ever having to change those settings. So after getting frustrated I've changed from the white pla filament shown in the last post to natural pla and this seems to have fixed it. I know that different colours of pla extrude at different temperatures but I didn't realise the results could be so different! Both this natural filament and the previous filament were printed at 195 degrees on a bed of glass at 60 degrees.

Also my overhangs have printed much nicer with the natural pla.

Maybe my white filament is defective as I have printed previously with different rolls of white pla with no issues. I think I'll have to do some different temperature tests.

Thanks for the help.

Jason

[andrewsi]

You could try knocking down the temp on the white by 10deg or so and see whether it still feeds reliably - a little colder and it'll probably ooze less. Some colors are definitely more viscous than others at particular temps.