[Iano]

Hi All

I need to find the centre of a countersunk hole which has been cut into a piece of 3mm thick brass - the hole is 3mm in diameter and the countersink is 5.5mm in diameter.

So I was wondering if there is a tool that will be small enough to find exact centre.

Thanks

Iano

[rewster]

Hi All

I need to find the centre of a countersunk hole which has been cut into a piece of 3mm thick brass - the hole is 3mm in diameter and the countersink is 5.5mm in diameter.

So I was wondering if there is a tool that will be small enough to find exact centre.

Thanks

Iano

You could use a tiny probe and Hoss's probing utility. It has a great center-finding function.

[kd4gij]

Heres how I have done it. Get a 3mm dialpin about 1" long stick in the hole then put in the mill vise Bring the quil down and move so you can chuck the pin in drill chuck. then adjust till you can slid pin in and out with quil.

[hoss2006]

Use the pointy end of an edge/center finder.
Put the tool on the chuck, turn it on slow, feed it down till it touches the inside of the hole,
adjust the x and y till it runs true.
LittleMachineShop.com - Edge and Center Finder
A wiggler works too.
http://www.littlemachineshop.com/pro...ory=1261091193
http://www.littlemachineshop.com/vid...erKit30fps.wmv
Hoss

[Iano]

Hi thanks guys - will try them ideas out.

Iano

[WOTDesigns]

I would use a center finder as hoss said. LMS also had the starrett center-edge finder for $23.

LittleMachineShop.com - Edge and Center Finder, Starrett

I bought the cheap one from LMS and it developed/had a burr on the center finder side that prevents it from running true. $25 for a tool that will last a life time is a good deal.

[eartaker]

If you don't have a center finder a crude way of doing it would be to put a 3mm drill bit in your spindle (NO NOT TURN SPINDLE ON) and adjust your x/y until you can slide the bit through the hole..... not the preferred method but it works.

[gixxer-harry]

At the end of this video is a clever way to do this (5.45)
[nomedia="http://www.youtube.com/watch?v=J4EtmJhDYHQ&feature=mfu_in_order&list=UL"]YouTube - ‪Machining the Model Stickney Engine with Lathe and Mill‬‏[/nomedia]