Ballscrew Nut-blocks, Power Supplies

I'm going to use the ...McMaster-Carr standard accuracy class (.004/ft)
$1.00/inch ball screws, ballnuts for $18 each. .631 dia. x .200 pitch
"value-priced" series. Everyone building Gantry routers probably will.
Since we all ....need to make an adjustable block to mount two ballnuts
per screw for no backlash.... and I bought the 15/16-16 Tap needed...
Would anyone like to borrow the tap and make me two blocks while you are
at it? I'm more of a woodworker than a machinist, and this piece is one
of the stumbling blocks (also need cheap end block bearing arrangement,
2 pc)

And I appreciate all this discussion about power supplies and
transformer configurations.... I hope they make it to the FAQ's.

Sources I've found:
24VAC 10 Amp Transformer ($17.99 @...)
20,000uF 50V caps ($3 ea. @MECI) (& 50W bleed resistors)
20Amp DC SS Relay ($10 @...)
4 shielded & twisted pair cable ($12 per 75' @ All Electronics)
4.5" x 1.75" x 3/32 anodized box section, scrap from commercial door
jambs.