[Chazaxl]

Chazaxl,

from the renderings it appears that the cutouts in the gantry side support are hollows that go all the way through. If that is the case, the most simple improvement is to place a 3-4 inch thick wall inside the hollows tying all of the beam segments together. Ideally it would probably be in the center but if it was offset flush with the base it would make for a good mounting surface to the base. It will improve the rigidity a lot. Just by doing those two things.

You might consider building the molds of thick fiberglass epoxy and then filling the center with concrete. Or make all of the cement castings undersized and laying up at least a half an inch of epoxy fiberglass. It will make the structure much more stiff. The concrete will offer very good damping. Ideally you would place a few pieces of stainless steel rebar in the concrete if you have the budget to do it.

Also, the sides of the base most likely need to be thickened up since they support the connection between the gantry structure and the bed. I would thicken them by at least two or three inches. You might be able to reduce the center web in the base a little bit. Also, to reduce resonances it might be best if they were offset a little. Not perfectly symmetrical.

Paul

Thanks. Not sure I understand how the fiberglass epoxy adds strength but will take it for what it is. In terms of the wall, (yes its hollow through) can you draw what you mean please?

In terms of rebar, my understanding is the rebar 'only' works if the structure cracks. It has no 'role' in providing strength, is this incorrect?

I can narrow the walls, the current plan is show using 4 x 110mm pipes to create the core 'hole' but I can reduce that.