8x4 router build. Steel base & Aluminium gantry gantry

[D-man]

I think Jazz is saying that using the 9 cross beams will make levelling the extrusion very difficult. In effect you will be creating 9 points along the length of the machine which will need to be perfectly level to get the extrusion flat. Looking at Deans drawing you can place the extrusion directly on the frame length or even better, do away with the extrusion and fit the rails directly to the frame.

Yeahi understand that bit, however bolting the extrusion to the box section would pove difficult without the need for brackets along the extrusion. The way i was looking at it was i would be able to bolt directly into the extrusion bu going into the crossmembers to add the nuts.

Something i havent mentioned, and i apolagise is the fact i would of been bolting the cross members onto the top of the frame. for ease of removal and any smimming that possibly would of been needed...