Gash under first layer
Sometimes my prints have a gash under the first layer. The top of the layer looks fine. It almost looks like there was a hair on the printbed. I clean the printbed pretty thoroughly before every print. The gash doesn't appear every time. It's also not always the same shape. Any ideas what it could be?
Thanks for the help!
RE: Gash under first layer
I think you are saying it is between the bed and the first layer right? If so, it looks to me like some melted filament that is coming off the nozzle -possibly between the prime line and the start of the print proper which just happens to fall where the first layer will print. Is this PETG or PLA?
Hard to really tell from this photo, but it looks as if you need to go lower with your Z-offset. Can you post some pictures of a single layer print? Try this one from @fuchsr.
Cheers,
Tim
RE: Gash under first layer
I'm with Tim. Something dripped on the bed. Or a thin thread got dragged from the prime line over the bed.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Gash under first layer
Do you have animals? Maybe an errant hair is caught up around the extruder area?
Mini+MK3S+XL 5 Tool
RE: Gash under first layer
This is PLA. The theory about a thin line getting dragged from the prime line seems likely. I saw it happen once - although for that particular print there wasn't a gash (maybe because the thin line didn't get caught under the first layer that time).
Thanks Tim for the link to the calibration print. It helped me better tune the first layer - indeed my Z-offset should have been lower.
RE: Gash under first layer
No animals but I will inspect the extruder area. Thanks Razor.
RE: Gash under first layer
It turns out there were very fine old PETG wisps stuck on some of the wires coming out of the extruder. They were pretty hard to see without looking very closely.
Thanks all for the help!