Dose anyone explain me Live Z?
Hey everyone,,
My understanding is that the Live Z is a "fudge factor" for the nozzle height. Basically, the machine lowers the nozzle to "0", but due to slight variations in PINDA measurements, bed heights, belt settings, etc. the known 0 might not be physical 0 so you have to adjust the actual nozzle height just a small amount, which is the Live Z.
So, my real question, if the bed height is at the same height, the nozzle is at the same height, and I am using filaments that are all 1.75 mm, why do I have to readjust live Z per filament type? What number is changing that causes live Z to need to be reset between PLA and PETG for instance?
Just curious and trying to understand how this all works..
RE: Dose anyone explain me Live Z?
Hello,
From what I would guess in the build of the printer there are tolerances with the mesh of the gears, belts, expansion and contraction in regards to heating and cooling. All of which over a number of prints can slightly change the value of the Z axis. PLA and PETG melt, flow and extrude differently so I would assume that and other materials can affect Live Z.
RE: Dose anyone explain me Live Z?
My understanding is that the Live Z is a "fudge factor" for the nozzle height. Basically, the machine lowers the nozzle to "0", but due to slight variations in PINDA measurements, bed heights, belt settings, etc. the known 0 might not be physical 0 so you have to adjust the actual nozzle height just a small amount, which is the Live Z.
Live-Z adjusts the 0 position. PINDA position, bed thickness or a variety of other factors can cause the position to vary slightly. When you adjust Live-Z, you're moving the 0 position. You generally want to re-calibrate Live-Z whenever you've made physical changes like swapping nozzles, installing a new type of flex sheet, or moving the printer.
When mesh bed leveling is done, it calculates slight variances from that 0 for specific parts of the bed.
So, my real question, if the bed height is at the same height, the nozzle is at the same height, and I am using filaments that are all 1.75 mm, why do I have to readjust live Z per filament type? What number is changing that causes live Z to need to be reset between PLA and PETG for instance?
You technically don't need to. A lot of people prefer to adjust Live-Z up a bit for PETG to reduce the first layer squish due to the characteristics of PETG (nozzle scraping can cause crumbs to form), but I frequently switch between PETG and PLA without recalibrating Live-Z. The top finish of the 1st layer can be a little rougher, but that's rarely seen on a completed print. I've heard of adjustments of 0.2mm, but I might back it up (make less negative) by 0.02mm.
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