Feature Request - TopDown printers

[Kvirre]

Hi,

Would be nice if there was a Z-axis compensation-parameter, for the top-down printer systems
To compensate for the linear amount of displacement of resin, as the Build-platform descends bellow the surface.

This compensation could be expressed as : XX mm / mm (retract XX mm for each mm on Z axis movement after homing)


| |
| | <- Rods (known diameter / volume)
| |
| |
--------------- <- Resin surface
| |
| |
============ <- Build platform

[PacManFan]

I'll look into it. I know that when the model goes further into the resin, the volume of the arms holding the build place will displace more resin, causing the level to rise.

[Kvirre]

Exactly, once the platform goes below the resin surface, the raise of surface-level should be linear (most likely if the the arms holding the platform are uniform).
And easy for the user to calculate : First move platform to surface-level (make a mark), then all the way down to the bottom of the tank (make a mark)
Then just divide "surface raised" with "moved in Z axis"

PS.
Another feature (a bit more complicated perhaps), would be to compensate for volumetric shrinkage when curing.
This could be done by calculating : current exposed surface-area * z-move * shrinkage factor = decreased volume (for current z-move)

although this might me negligible compared to the first "issue"
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