After redesigning the frame to be made entirely of 1/4” aluminium, I sent the CAD files through to my friend. Not long after that I received a very heavy delivery from him. All up it probably weighed about 12kg.

This thing is huge!

I had to somehow drill holes into the edge of the top and bottom plates. I decided that three M3 bolts per joint would be sufficient. My friend was able to mark pilot holes in the side plates so drilling them was straight forward. I placed them together in a bench vice and used the side frame to mark holes in the top/base. The holes were then very carefully drilled using a drill press. I still managed to snap off two drill bits in the new holes. Luckily they were both on the same edge so I was able to designate this as the “back” tower.

Drilling holes in Dad's workshop

Careful tapping of the M3 threads

I may have snapped off drill bits in some holes and had to re-drill just next to them.

A very straight, strong and stiff frame.

As expected, when the grooves were slotted together, the frame pulled true. I was very happy with the rigidity and strength. It easily supported my full weight sitting on top and didn’t flex at all.