mesh compensation too aggressive?
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@gnydick said in mesh compensation too aggressive?:
@fcwilt yes, it smooshes too much in some areas, and I have a great bed.
But the point is, it is literally impossible to get a perfect first layer if it's not following the contour.
I am using 3.4.6 on five different printers and mesh comp works fine. I have verified that it follows the height map exactly.
Perhaps the problem lies in 3.5.x?
Do you set the Z=0 Datum at the same fixed XY position when creating the height map and loading the height map?
Frederick
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@gnydick What happens if you run the same test print without a taper set? Is the first layer any better? Can you post a screenshot of the mesh display from DWC including the stats (min/max deviation etc.).
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@fcwilt I'm not following what you mean about the z=0.
How are you confirming it's following it exactly, considering the source code and documentation show the first layer is subject to taper, making it impossible to follow the map exactly.
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@gloomyandy I'll try it and let you know.
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@gnydick said in mesh compensation too aggressive?:
I'm not following what you mean about the z=0.
When you use your Z probe by executing a G30 command at a fixed XY location (always the same) you are setting the Z=0 Datum.
How are you confirming it's following it exactly, considering the source code and documentation show the first layer is subject to taper, making it impossible to follow the map exactly.
I created a heightmap using a text editor that had deviations ranging from 0 at the left edge to 100mm at the center then back to 0 at the right edge. With these large values it was easy to move the nozzle to various X positions and measure the Z position of the nozzle.
In any case the amount of taper adjustment applied to the first layer is very little.
Frederick
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@fcwilt I think you're asking me if I home my Z axis at the same place every time. Yes.
What I always do is home, then tram, and then use the printer. I don't home again after that. Maybe I should.
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@gnydick yes, you need to rehome Z after tramming because the plane may have shifted and with that Z is out of whack.
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@gnydick said in mesh compensation too aggressive?:
I think you're asking me if I home my Z axis at the same place every time. Yes.
Yes and no.
Since I don't home Z using the Z probe I always speak of setting the Z=0 Datum rather than homing Z.
Frederick
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@gnydick It is also a good idea (assuming you use a probe to set Z=0) to home so that the probe is over one of the points in the bed mesh. If you do that then that point should read 0 in the mesh (or very close to it), if that is not the case then there may be a problem with the mesh (or possibly there is a problem with repeatability of Z homing).
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@gloomyandy good advice