Hi JCB

Thanks for commenting.

I'm by no means an expert, so I'll defer to one of the J's on this, but my reasoning was that when the cutter is moving through material in the X-Axis (either towards or away from the camera in that shot), then the leverage force would be at the cutter opposite to direction of travel.

The fulcrum point would therefore be at the lower Y axis bearing and would be trying to deflect the upper bearing mounting point (or the top of the gantry). As the distance between the lower bearing and the cutter tip is going to be considerably shorter than the distance between the lower and upper bearing point (the other side of the fulcrum), then the deflection should be minimal/reduced.

Of course the forces may cause the gantry mounting brackets to flex, but I have yet to see any by leaning into the gantry at the top - I wish the same could be said for the yaw in the gantry, due to only having one X-axis ballscrew however, but this is to be shortly remedied :)

At least that's the theory ;-)