Flat Face Blues

What changes do I need to make to get a gapless first layer?

(Using latest version of CURA with a Mini2.)

It looks like either your nozzle is too close or two far. I can’t tell if you’ve got raised lines or divots. Post a pic at more of an able from the side?

THANKS:

TBH… that’s a good looking first layer. The extrusions have flattened out enough to create good adhesion.

If you want a completely flat face, you’ll need to get the nozzle closer to the bed. Increments of .1mm until the bottom starts to flare out (elephants foot). You’ll need to search the forum for the proper GCode commands to accomplish this… I have an older TAZ and perform this mechanically with the Z-end-stop.

Alternatively, the gcode offset setting in certain slicers can accomplish the same thing. Again, use Z-axis increments of .1mm to your likng or until the bottom layers start to flare out.

Make sure you have a good tool to remove objects from the PEI bed.

Another way of improving that bottom layer without messing with your Z-offset would be to try increasing your initial layer flow rate in Cura slightly. This will cause the first layer to be extruded a bit thicker to help fill the space between the nozzle and the print surface. You can find the initial layer flow in your material settings in Cura 3.2.21 (or 3.2.23 which is now our most current version of Cura as of yesterday) in the custom settings section.

I’ll try what you have suggested today. Thanks

And by the way, in the most recent photo, why is there a “trench” around the center hole??

Post the STL.

If it’s not “designed”, its probably a slicer computational (sp?) issue… try changing the top layer infill pattern, perimeter #. That might help the slicer come up with something a little better.

That’s pretty much a perfect first layer. If you push the flow rate too much to smoosh the layer so there are no determinable nozzle pass lines, you’re risking having more issues like chewing your filament in the hobbed bolt from back pressure.

You’ve got a darn good first layer there. I wouldn’t mess with it .

OK Thanks Jim et al.

I mucked around a bit with profile settings and have returned to the original.

Some of my first prints were the bearing holders and the build plate faces were real smooth:

Those first layers look really good IMO. The first ones should help keep things on the bed while still offering easy part removal when cool. The second pic, of the bearing holders look good as well, but remember that printed part adhesion will increase inline with the part size.

That last picture, while flat, it borderline overextrusion which can lead to other issues depending on what filament you use. A good first layer should have discernible nozzle passes. If they’re smooshed together too much, you’re going to build up nozzle back pressure and risk grinding.

Just something to keep in mind. IMHO you’re probably 1-2% too high on flow rate. Glad you’re happy though!

I’ll try backing flow off to 98%.
Thanks for tips!