Corexy calibration/compensation
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Hi,
On my current printer, a corexy (3 Z-motors). In the default configuration I have configured Auto bed leveling, it only uses 4 points, one central and the others near the Z axes, accustomed to my delta, which used 12, they seem few to me...
A- Is it worth putting more points? (or nothing is gained)
Others
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I guess if... There is some gcode to see the result of the calibration, and the adjustments you have made to the Z motors
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After that 1 calibration... Where do you set the motors in Z. Can it be interesting to do a second calibration, to check that the results are consistent?
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If I wanted to automate that second calibration... How could it be done? Adding it in bed.g? Or doing a macro, with two calibration?
Another doubt is the compensation, with the gcode M557, in config.g, you define the density of points for the mesh.... But is there a possibility to define the points where it is tested manually (similar to how the points for calibration are defined), in a independent file.
Why would I be interested in this? To define areas where I want more detail / precise in the mesh, I can think of several cases:A - Most of the pieces I print, occupy less than 150x150mm in plant. Make the mesh denser in that area, where I could use more detail
B - By use, I have detected that an area of the bed has been bended, so that the impression adapts better, in that area have more density of points
A third way would be to be able to combine 2 meshes. A general of the whole bed for example every 75 mm or more and in the central area a more detailed one every 15 mm, for example
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If you specify 3 points near the Z axes after leveling the Z plane perpendicular to XY will pass through those 3 points. If that is what you want then you are done.
Alternatively you could specify 4 points near the corners of the bed.
I have not found a need for other than those two options BUT my beds are quite flat to being with.
Frederick
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@fcwilt I seem to have read in the documentation of the wiki, that to use the auto level, in a corexy, with 3 motots in Z ... Use at least 3 points, as close as possible to leadscrews
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3 points is ideal if you have a flat bed. 4 points or more might help compensate for an uneven bed surface. In general though, level with 3 or 4 points and then do a more detailed mesh.
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@peirof another doubt related, its these printer uses a Bltouch as Zprobe.... That is placed about 20mm from the nozzle in X. How do you compensate for that? Because the following will happen:
A- When you try a point, if by chance there is a hole/mountain in the bed, the nozzle will not be printing where it thought of height
B- When you try a point at x=0... There is a very high probability that the Bl touch pin will be out of the pad
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You need to measure the offset in XY and enter it in G31.
For the mesh, you must create a mesh size that keeps the probe within the bed area to make the best use of the area. The firmware will skip points it can't physically reach.
For bed.g and homing files you must position the probe where you want first.
