# Mini first layer troubleshooting **URL:** \ **Category:** LulzBot Mini\ **Created:** [February 1, 2016, 6:14pm UTC](https://forum.lulzbot.com/t/mini-first-layer-troubleshooting/2873 "2016-02-01T18:14:35Z")\ **Posts on this page:** 1\ **Showing post:** 1
**Author:** ![John\_Mc](https://avatars.discourse-cdn.com/v4/letter/j/65b543/32.png) [@John\_Mc](https://forum.lulzbot.com/u/John_Mc)\ **Post date:** [February 1, 2016, 6:14pm UTC](https://forum.lulzbot.com/t/mini-first-layer-troubleshooting/2873/1 "2016-02-01T18:14:35Z")
Questions on trying to dial in my first layer on a Mini. My first layer is going down a bit rough: there are ridges or fins parallel to the direction of the interior printing where one line meets the next. Is this normal? It shows up most in the first layer, by the next layer, it looks better, and I’m happy with the surface quality on finished parts I’ve printed. I think I’ve got the e steps and the filament diameter dialed in well. To better diagnose, I printed a 75mm test disk at .20mm thick (starting from the Cura PLA standard quality profile, I reset the thickness of all layers to .20mm). Measuring out on the perimeter, on the smooth tracks which are laid down first, I get about between .007" and .008" which equates to about .18 or .19mm. measuring toward the center, where the ridges are, I get .22mm. Which number should I be looking at to determine if my z-offset height is were it should be? Is there a better way to determine the actual printed z dimension being laid down? Maybe print a single trace? I printed another 75mm disk at .40mm thick. It printed in 2 layers. the ridges fro the first layer were no longer visible, and the ridges from the second layer were much less pronounced - almost as good as the finished surface on some 5mm thick prints I did earlier. Out on the smooth perimeter, I get .32mm. In the center, where the ridges are, I get readings from .39mm to .41mm Does this sound like something I should be trying to fine-tune? Bed adhesion is good (in fact, I wouldn’t mind a bit less, but I haven’t tried to adjust for it, since I figure things may change once the PEI surface is no longer brand new) --- _[View the full topic](https://forum.lulzbot.com/t/mini-first-layer-troubleshooting/2873)._