Took several ideas from different parts and designed a Z axis brace and adjustable feet that includes easier to find (and cheaper) hardware. The threaded foot pads include a dovetail O-ring retainer for a 7/8" OD, 11/16 " ID O-ring (3/32" thick, AS568 -115) to dampen vibration. The foot supports have hex cut-outs to install the 3/8"-16 nuts.

Fasteners used are 3/8"-16 UNC - easily sourced from hardware stores in North America. Cap head screws to attach the parts to the frame are M3-.5 x 16mm

---IMPORTANT INSTALL INFORMATION!!---
To install the mounts or feet remember to clamp the metal frame before removing any of the screws. Failure to do this could result in a twisted frame and linear rods.

BOM-
Printed parts
-Z brace Bottom Left
-Z brace Bottom Right
-Z brace Top Left
-Z brace Top Right
-(2) Support foot small
-(2) Support foot large
-(6) Support foot pad, 6 is optional, 4 are required minimum.

Hardware
-(20) 3/8"-16UNC grade 5 nuts
-(2) 3/8-16UNC threaded rods x 16" long
-(28) M3-.05 x 16mm cap head screws
-(6) 7/8" OD, 11/16" ID (-115) O-rings