Sanity check - tramming gantry
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I am comissioning a new printer build. The mechanics are that of a CR10 so a tower on either side for lifting the gantry. There are two independent z motors.
My procedure is as follows:Set a gantry height suitable for a gauge block between the frame bottom rail and the gantry. While keeping the stepper motors powered up to avoid any shifting of Z positions, I manually (by forcing one of the Z stepper motors) adjust things until the gantry is the same height on both the left and right side of the printer. The idea here is to make sure the gantry is level with respect to the frame. Note that even though I use gauge blocks, a slight deviation from level should be expected.
Without powering anything down, I now do a basic bed mesh scan and adjust the 4 corners of the bed for the best fit. In my case no adjustment was made at this point.
I then run a measuring procedure to have the Duet equalize the gantry with respect to the bed. This is done with mesh bed compensation turned off.
Here is where I have trouble wrapping my brain around things ....
After the gantry is equalized, if I run another bed mesh, I get a substantially different bed mesh picture. I guess this is expected as the gantry level is adjusted slightly.
My concern is that the bed mesh is screwing things up somehow. Note that bed mesh compensation is turned off during both bed mesh generation and gantry equalization.Does my overall procedure make sense?
Should I do mechanical bed levelling with the 4 bed corner screws after the gantry levelling? It would seem to me to end up in a tedious circle of adjusting the bed, then re-levelling the gantry with respect to the bed, then re-adjusting the bed screws and over and over. What is the correct sequence of steps? -
If your gantry is level to the frame, level the bed to that. Then run a mesh.
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@Phaedrux Thanks, that is what I did but as soon as I do the gantry levelling (after the physical levelling and then running a bed mesh) it screws up. Well at least I know that my logic is sound. I guess I will have to tripple check that the location specification for the two z screws is correct. That's about the only thing I can think of that would mess up thingst
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@Phaedrux, thanks, you got me on the right track. M671 command was incorrectly formatted.
