Prusa i3 MK3 latest release first layer calibration issues

Question

I am trying to get my first layer calibrating done but no matter what I do, I can not get the lines sticking to the bed.

My first question is the distance of the P.I.N.D.A. What I did was what Prusa recommends on this pic:

I am using Prusa Slic3r with PLA and all default values. I am doing the first layer calibration of the setup menu and got the lines which you can remove and the last square which the nozzle is picking up so you don't have it on the print bed. The very first line on the left corner is not really squeezed. I am looking for some greenhorn help here.

Answer 1

Calibrating the first layer height involves two steps:

The first step, as illustrated in that picture, is to adjust the PINDA probe to be roughly the right distance above the nozzle. The PINDA only has a sensing range of about a millimeter, so if it's too high, it can't detect the printbed; if it's too low, it will interfere with the printed object.

The second step, which you're having trouble with, is to calibrate the exact distance between the PINDA and the nozzle tip. The printer prints out a test pattern; while it's printing, you turn the the dial on the printer control panel to adjust the "live-Z" value. Typical values for a properly-assembled printer are between -0.5 and -1.0 (more-negative values are closer to the print bed). If the live-Z value is outside that range, you need to adjust the position of the PINDA probe.

The official Prusa procedure is good for getting a rough calibration. If you want more precision, the "Life adjust Z - my way" procedure on the Prusa forums is good. Basically, you print out a large one-layer square, adjust the live-Z value halfway through, and see which half has a better first layer. Repeat until satisfied.

Answer 2

Your problem is that you need to define the sensor to nozzle level offset and store it in the printers memory.

When you have homed the printer, you should end up with the nozzle at a certain level where the sensor trigger point is now defined in relation to the bed. Next step is to relate the trigger point to the nozzle level, instruct the nozzle to go down to the build plate (placing a sheet of paper on the plate) by using the buttons of the menu to move the Z axis. When you feel friction when you pull the piece of paper, you reached the correct offset. Now store the value you read from the Z axis display as Z offset in the menu. Alternatively use G-code M851 Z-x.xx, where x.xx is the value you read from the display. M500 will store it in memory.