Ugly First Layers ((RESOLVED))

Hello everyone.

I’m having a bit of an issue since I changed out my PEI sheet on the print bed. The first layers are bulging out and just plain ugly and while it’s printing those layers it looks as if it is over extruding with the print head down in the extruded material rather than running over the top of it.

I ordered a PEI sheet off Amazon and it’s thinker than the stock piece so I’m guessing that is whats causing the issue. I thought that during auto bed leveling the calibration would notice the bed was higher since the little metal disks are higher because they sit in top of the PEI sheet. But since that’s the only thing I know of that’s changed since I started having this issue I’m guessing that’s what the problem is.

I’ve looked but I have no idea which setting in Cura (v18.03) I need to change or even how much to change it by.

Here is a link to the PEI sheet I purchased.

I’m no 3D printer guru. For me the printer is a tool and not a hobby so please excuse my ignorance.

Any help is greatly appreciated!

Thanks in advance.

-Mike

In cura, go to machine settings and set z-offset to 0.1 and see what happens.

It’s probably more about overextrusion though. In the advanced settings turn down the first layer flow rate. It defaults high to make sure parts stick, but it’s a little overboard IMO.

Thanks for the quick response!

I changed the z-offset to 0.1 and am printing something now to see how it turns out.

I’m not sure where the settings are for first layer flow rate. I checked in machine settings and under the advanced tab under full settings and I don’t see anything for flow rate.

The part I’m printing now looks good but it’s only 2mm thick and tall so I’m not sure if this is a good test. After this piece finishes I’ll print another of the pieces I was having trouble with and see how it comes out and report back.

Thanks again!

For the rates you need to switch to advanced mode. Make sure you say yes when it asks about copying settings. That will give you a good starting point.

Raising the z-offset to 0.1 seemed to help but didn’t fix it so I changed it to 0.2 and did another print and the bottom layers are once again printing cleanly!

Thanks again for all your help in getting this issue resolved!