On 2 Oct 2005 06:42:00 -0700, wrote:

I need some guidance on figuring out what the bolt hole co-ordinates
are to build a drive flange. The hub I need to bolt to has three
holes, evenly spaced with a center to center dimension of 3.607. How
do I calculate what the bolt hole x-y co-ordinates are to drill this
when held in the mill vice? thanks in advance, ron


Hey rbce,

A center-to-center of bolt-hole to bolt-hole of 3.607 will have a hub
center with a radius or 2.0825.
Assuming that this hub center is located at X=0, Y=0, and assuming
that to start one of the bolt holes is on a line drawn perpendicular
to the X0 position, then the three bolt holes will be at:

#1 X 0
Y 2.0825

#2 X -1.8035
Y -1.0413

#3 X 1.8035
Y -1.0413

If you want to start one of the bolt holes at X0, Y0, then it would
be:

#1 X 0
Y 0

#2 X -1.8035
Y -3.1238

#3 X 1.8035
Y -3.1238

If you have a specific in mind as to lay-out, let us know what it is,
and we'll get applicable's.

Take care.

Brian Lawson,
Bothwell, Ontario.