Prusa i3 MK2S ::

3D Printing
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Prusa i3 MK2S :: Take II
Z Axis

Thanks to chad.r2 @ prusa (https://is.gd/qnJZWw) forums whose method I used to calibrate Y-to-Z, I had an easy time working on it. Used empty boxes from Prusa to support the ZPlate and insert the Y gantry at a pre-set position (roughish 100mm).
It was a bit tricky to lift the bed so that when inserting the ruler between the bed and carriage the line on the back of the bed is very close to the ruler’s edge so I can as close as possible eye-ball parallelism.

It wasn’t easy to manually keep the belt at a proper level but finally I managed to very easily do that by inserting a hex key (included in the kit) in the set-screw of the motor pulley and use it as a lever to rotate it and hence raising/lowering the bed. Luckily I didn’t need to modify the pulley’s rotation relative to the motor shaft because it rested against the motor mount at the perfect position so I could eye-ball the parallelism between the ruler edge and the line on the bed.

I guess the pictures talk for themselves a lot better. I am just very surprised how easy the whole process was compared with what the Prusa manual has.

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That is clever! Maybe I ought to redo mine, it’s still a little off…

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@Peter_Hertel Yeah, I still believe that troubleshooting and fine-tuning and correcting errors is one of the least well-thought things of this printer. You can’t have access to everything with it standing, have to turn it around, unscrew things, use your immagination and have high tolerance for frustration :slight_smile: … We’ll get there somehow :slight_smile:

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@Florian_Ford ​ great idea! I love it.

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I agree it’s a good idea to have a position to be able to work on all calibration but the way Prusa built this one is very frustrating because you have the under-carriage nuts that are used to adjust both bed skew (rotation around Z axis) and bed tilt (rotation around Y axis) and when you thought you have adjusted one and you strive for the other, you screw the former, or at least some gains you have achieved there.

Ex: bed skew is solved, even bed tilt on one section, but from top to bottom there are many many sections and because the YCarriage is most likely twisted in some way, the calibration you did for that one section (say: middle of the bed) doesn’t work for other positions of the bed on the Y axis.

See in image below:

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