David, I made an alternate version of the Fusion 360 model of the top mount system based on your onshape model:
Is this the linkage kit you’re sending Gero? The horizontal arms look quite a bit larger than the one I have on my machine.
Gero is getting a kit like you have, just with 7" (hole-to-hole) horizontal arms
instead of 5" arms.
looking at the pricing, if I can get someone to cut this properly, it is close
enough to the same price to have longer arms that it’s not worth making two
versions of the kits.
I really like that center support. I may try to machine one of those myself,
it seems like it would make the assembly much stronger!
As long as both sets of horizontal arms are anchored to the same piece of wood
(as opposed to pillars like your model showed), it’s pleanty strong enough and
the metal doesn’t improve it any.
But the pre-cut metal makes it so that there is no possibility of the holes
being in the wrong place (which would make the geometry of the arms not work),
and potentially simplifying the mounting.
If I do make these (and they continue to sell after the 'official ring mount’
becomes available), there will be extra center supports, so I will look at
sending them out to people who have the older version of the kit.