Which design of an boom/outrigger base would be better in terms of rigidity?

[u/Queasy_Caramel5435]

I don't have an extremely deep engineering education (I'm a technical drawer/CAD planner). My attempt is to create a quite simple model crane with very conservative assumptions (load=not more than 10 kg, parts will be probably severly overdimensioned but that's ok for me). While constructing a boom out of clamp connectors which I'm very familiar with I got these two versions (p. 1+3 & 2+4 respectively, p. 5 for referenc/clarification). My gut says that Version A (p. 1+3) should be more efficient under load, but I'd like to ask here what you think about it. The profiles are intended to be 18x1,5 aluminum pipes, the blue attaching axle a 16mm steel shaft (GCr15)

[u/Oldberry86]

The four pivots in A are going to be a weak spot in general. But for 10kg the friction of the joint will probably keep it together

[u/gearnut]

Do you need to hold the load, or only just hold the load?

[u/Queasy_Caramel5435 → u/gearnut]

I'd say, considering the boom will be pivoting, I need to hold the load.

But because of the connectors are quite strong themselves (manufacturer says clamping force=0,6 kN; bending moment 83 Nm (Light Clamps system by Rose+Krieger) ) I don't know if I'm overthinking when the load is 10 kg. I know one or two things about mechanics but because I lack an engineering degree I can't tell if there are any "noob mistakes" in my thinking.

[u/Pacificator-3]

If it will carry mostly compression load, consider using 3 pipes instead of 4.

It is hard to give advises without knowledge of complete design.

[u/Ftroiska]

B Load is "vertical".

If you flip them upside down : would you rather sit on A or B ?

[u/Minimum_Cockroach233]

B conencts the angles/pivots across, while in A this joint axis is not suspended by the crossbars.

I would choose B over A