Assembling the underframe

How do you assemble the frame under the 1000mm wasteboard? Earlier in the instructions, it said to mount the 2 1000mm extrusions to they Y-Plates, but now it says you need them. If I slide the extrusions off the preassembly nuts, will it harm the structural integrity of the machine? Do you just slide the whole wasteboard assembly on after it is done or how do you mount it to the machine?

I assembled the extrusions that make up the base and slid the spoil board on afterwards. I found that if I had the X-axis moved right to the back, I could slide the spoil board in over the front Y axis plates.
This was before I mounted the spindle.

How did you mount the wasteboard to the center bar and how did you make sure the preassembly nuts were in position so they could be tightened

Did you see Step 13?
http://x-carve-instructions.inventables.com/step13/

We Did, but you so to use the two extrusions in the Y-plate step and it’s very confusing how you had it worded.

The Aluminum Extrusion 20mm x 20mm Black 1000mm and Aluminum Extrusion 20mm x 20mm Black 958mm are for the waste board. The 6th and 7th picture shows how you slide the pre assembly nut through the extrusion. You screw it in enough that you can slide it through the extrusion. It then centers itself in the extrusion.