If you need a jig for drilling a hole in multiple aluminum axle
frames, you might have a local machinist or trade school student make
a jig with a 1X1X2 metal block. They can accurately drill the guide
hole and it would likely not cost too much to make such a jig.
The trade school students, here, appreciate a nice gratuity for small
projects, as that, and the instructor encourages the students to take
on some practical projects, as that.... same with the welding
department students/instructor. I occassionally have a project for
both departments. For the machinist students, the instructor asks
that I supply an accurate drawing, a set of precise plans, for the
students to follow, rather than word-of-mouth type instructions.
I like to try making my own jigs, though, so this may be your