locating to a centerline of a hole that use to be round???

[dtwo]

I am designing a drill jig and need to locate it by the centerline of a hole that use to be round. The current holes are not round due to wear between them and clevis pins. The hole geometry varies with the amount of wear.
The jig will be used to add several clearance holes for mounting a plate and they need to be referenced from the original centerline of the 25mm holes. For most of the holes the wear is to one side so there is part of a radius that could be used.

Is there any thing I can use that is low cost and easily machined to accomplish this?

 

[ajack1]

Would a tapered pin do what you require?

Either sprung or locating on a smaller diameter as a pilot, at least that way you are locating on the “centre” of what you have or at least on 3 points with extra clearance.

 

[toolingguy]

have you tried diamond shaped locating pins?