Hello Folks,

Progress update, I've got the X and Y axis moving, Z axis next!

I did some load / deflection tests and I have to agree with JazzCNC about the stiffness of the axis.
First I wrapped a strap around middle of the X-axis linear rail (with the Z axis out of the way) and applied various loads measured with a luggage scale. I then measured the deflection with a DTI. Secondly, I moved the Z-axis to the middle of the gantry lowered the z-axis to it's lowest position. I tied the strap to the spindle collar and repeated loading and measuring the deflection.
Once I had a base line set of numbers I clamped a piece of box section behind the X linear rail and repeated my test and saw a very noticeable improvement in the stiffness in the Y-direction and twisting forces on the Z-axis. So I think I'm going to add this regardless to beef up the gantry - every little helps!

I have had an idea of how I can add a second support above the lead screw as JazzCNC described but that will take some fabrication - so I'll park this for now.

I'm probably going to go for a little 500w spindle for now as a short term solution. This will hopefully get me cutting something at least!

I'll post some photos and vids when I get the Z- axis operational and wire in a few of the limit/home switches.

Peter