Re: [CAD_CAM_EDM_DRO] Re: Locating already drilled holes

Alan Marconett KM6VV wrote:

>
> OK,
>
> I saw one last night in a catalog, so what's a drill bushing? and what's
> it used for? Goes in the jig under where the hole is supposed to go?
>
> Alan

Yes - the idea is, suppose you have a batch of parts you want to drill
accurately located holes in. You make a jig with a metal plate under and
over the part held apart by spacers. Slip in the stock and you have a sandwich.
The lower plate you put some locator pins in. Arrange some locking device.
The upper plate you drill & ream oversize holes in to take drill bushings.
They're hardened and won't be cut by the drill. Usually they're a press fit.

Now you're guaranteed that the drill won't wander.