Thread: Fixed z axis to gantry design
Yes, I totally get what you are saying. Putting the bearings on the bed and the rails on the moving part makes good sense but it is maximising stiffness in the vertical Z direction. It is similar to the debate around conventional Z axis where it is often better to put the rail on the moving part for the same reason.
However, the bracing on the tower is primarily to address stiffness in the X direction. I've re-drawn the sketch to show the moving rails and FIXED bearings but the forcing (for X direction) is still the same and suggests bracing of the tower is beneficial.
There is also some Z direction stiffness from the bracing due to moment created by the offset of the tool from the tower in X which is independent of the rail / bearing arrangement.
Z cutting/ plunging:
In this topsy turvey arrangement I am advocating the block assembly width is tiny in comparison, so the rails are short.
If you could bolt the "base Frame" to a workbench this could look ultra neat.
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