Drilling Gantry for cable chain support

[Red_boards]

I see that the cable chain support is bolted to the gantry tube. I can't find a plan detailing this. Is it necessary to use a clamp strip for this or can the thin beam walls support the weight?

[JamesJ]

I drilled and tapped the gantry tube. The recommended minimum thread depth for 6 mm is around 4.7 mm and the thread depth in this case is around 3.1 mm. As long as you do not overtighten I think it will be fine.

[Gerald D]

I used big self-tapping screws. Big blind rivets will also be okay. The wall is thick enough to carry that light load.