Took about three hours to do the pair, since this mill is little more than a glorified drill press: a little sloppy and 100% manual adjustments and operation. Lots of triple checking everything to make sure you're squared up, and careful passes to prevent unwanted movement. But in the end, the finished product can be pretty decent. You'll notice slight variations from one side to the next, as I really don't do measuring (and sometimes the mills walk out of the chuck). I just kind of eyeball everything, and in this case, held the OEM nylon mounts up against my work pieces to set the angles.
Hopefully I will never, ever have another issue with arm mounts.



They're affixed to my 4mm carbon fiber chassis with stainless screws, and they are slobbered with red loctite!


Now I just have to do rear hub carriers, front arm mounts, front caster blocks and front steering blocks! Been through this once before on one of my GTs, which sports handmade 6061-T6 arms with steel hub carriers, caster blocks and steering blocks. Time consuming and labor intensive, but it's pretty much a one-time deal.