So the electronics, motors and cables have been completed.
I decided to make the base from steel and the gantry from aluminium. My choice for a steel base is that it adds weight and stability and because it is fixed it does not require additional motor power.
I also wanted to have the rail supported laterally and vertically along it's lenght. The rail is 2 inch by 1 inch bright mild steel and is attached to the sides of the frame. The backbone and turnbuckles let me adjust one side without affecting the other side. There are slotted holes in the crossmembers to allow for adjustments.
Rather than waffle on perhaps if I post pictures it will be clear as mud for everyone.
regards,
Rod
Perth, Western Australia.