Worthless update without pics. They will follow later today.
I have installed the center support on this table. It is adjustable. It is also the heaviest gage part I used. It's a 2" x 3" steel angle. About 1/4" thick.
It is supported on each end with Unistrut hung off the end 2" x 3" angles. Pretty solid.
I also installed homes on X, Y and A. I did install my channel for the echain as well, but both of those need adjusting. I needed more room to clear the gantry uprights on the top piece.
For the X, I had the echain attaching up at the top of the gantry, but will need to lower it down to the base of the gantry upright. Minor moves really.
Both interfered at the far end of travel one way or another. Unless you have a used plane, I would suggest setting these up with use of double stick tape until you are sure that you have good clearance everywhere.
You can think it through in your mind, but in reality, it works a little differently.
Anyway, I did get the motors cranked up. Yah! I need a lot more bracing.
The initial plan was to lock the wheels in chocks and cut like that. That will no be good enough.
The gantry will fly and it's not exactly light weight. Anyway, stay tuned. Better stuff coming.