does first layer height on simlify 3d overides prusa z first layer height calibration?  

RE: does first layer height on simlify 3d overides prusa z first layer height calibration?

Simply put, Live-Z calibration is establishing where zero is. You are setting an offset above or below where the PINDA probe detects the metal sheet. 

Not well documented is the fact that you are prevented from lowering the nozzle below 0.15mm using basic gcode move and extrude commands. So to answer your question, provided you select a first layer height 0.15mm or higher, the first layer height you specify in any slicer will be the what is used. If you specify a 0.20mm first layer height, on homing, the printer will move to 0.15mm above where it thinks zero is, then at the start of the print gcode, it will move up another 0.05mm to 0.20mm above zero.

Depending on how well you've calibrated your Live-Z, that may be a small difference from actual zero (the print surface). 

RE: does first layer height on simlify 3d overides prusa z first layer height calibration?

Clear enough, thanks! so i guess ideal would be to print at 0.15mm first layer height so it matches the z calibration on the machine.

RE: does first layer height on simlify 3d overides prusa z first layer height calibration?

Posted by: andres.m4

Clear enough, thanks! so i guess ideal would be to print at 0.15mm first layer height so it matches the z calibration on the machine.

I use 0.20mm 1st layer height for all nozzle sizes, except for the smallest (0.20 & 0.15mm). It provides enough coverage for good adhesion, a bit of forgiveness if the bed surface is uneven (a mini-raft if you will) and heats evenly for good adhesion. I haven't done any exhaustive testing though, so see what works best for your needs. 0.20mm is a common recommendation though.

I haven't actively used S3D for a while, but be aware that the First Layer Height percentage does some "helpful" things that can make life interesting. If you specify 100%, your 1st layer matches your specified Primary Layer Height, no surprises. If you specify a value greater than 100%, S3D will increase the amount of material extruded to account for the additional 1st layer height. However, if you specify a value less than 100%, S3D will extrude the same amount of material as at 100% with the logic that the extra "squish" improves 1st layer adhesion.

RE: does first layer height on simlify 3d overides prusa z first layer height calibration?

Actually, i just downloaded the S3D newly posted mk3 profiles and first layer height matches 0.15mm because layer height is set at 0,20mm but first layer is set at 75%... worked great with the test i tried. Im used to get a functional first layer but im aiming at having a perfect first layer smooth finish underneath for some projects im working on... this new profile improoved what i was doing before (printing at 0,3mm layer height and first layer height at 80% = first layer at 0.24mm) I also noted the profile works at a slower velocity compared with what i was used to print (below 3600) .. maybe those two changes improved the finish i got before on the print. 

RE: does first layer height on simlify 3d overides prusa z first layer height calibration?

Posted by: andres.m4

[...] I also noted the profile works at a slower velocity compared with what i was used to print (below 3600) .. maybe those two changes improved the finish i got before on the print. 

Having to use a spreadsheet to keep track of what speeds S3D was printing different features at is what drove me to Slic3rPE/PrusaSlicer! Glad it's working for you. Have fun with it!