Need Help! Z Axis gibb to ball screw connection

Hello All! I purchased a ZX7045 clone a few years back. It never would run at G-Code feed rating didn't matter what you changed the feed rate to it always ran at ( something like 1.5IPM). The machine died and I am in process of updating/repairing the BOB/drives/encoders. There were a few issues I found. One of them being the encoders used needed a 5vdc connection cuz the G320( legacy, now X ) doesn't output enough voltage. (Assuming this was the feed rate issue) There are a ton more issues, but those are coming to an end.......I hope!

The help I inquire about is about how to make a good, solid, flex free connection from the Z axis gibb casting to the ball screw nut. No pics attached because it won't allow a 6.23meg RAR file, when the popup states it should accept 8.58 M.

(Imperial dimensions)
Coupling block is 1.5x1.5x 3.75 to BS center. ( Aluminum)

The boss is about .800 in diameter ( which is the only holding point, other than surface tension) with a 1/4-20 screw connection.
With out disassembly, the BS is roughly 5/8 dia.

Its pretty difficult to see any movement by hand, however, with the head/spindle attached, its roughly .020 worth of visual movement/flexion before the head moves.

I'm assuming I need to increase surface area to something like 3"x3",add a couple more screws ( larger) and shorten the distance to the screw center by at least 1/2. Or, increase dia of the BS to 1.0" I haven't disassembled yet to verify the possibility yet.

I also don't have any build/repair experience with ball screws . Any insight there would be extremely appreciated.

thank you for your insights


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