Holding Center w/o DRO using Angles...?

[EmilioG]

I'm planing a new Finger Plate for holding small parts and stock.
The hard part will be drilling a through hole after the V is machined at a 45° angle.
The steel plate will then be layed flat after the V cut using an and mill. I need the through hole to
be dead center of the V channel. Is there a way of re-locating that V's center line after it's moved to
a flat position w/o a DRO? If the table and vise are locked, will the drill fall on the centerline after the
part is moved off the 45° angle?

 

[chips&more]

The outside edges of the drill bit will catch on the 45° V first. You want the center of the drill bit to locate first.

 

[Tony Wells]

May need to spot face with an end mill before you attempt to drill. As chips said, the drill will snag on the 45° side before getting to the root of the angle.

 

[EmilioG]

Maybe a center finder/wiggler would work? There has to be a better way to locate the bottom of the V, DRO not withstanding.
I plan to put a cross hole bushing on the one end of the V, so that hole is critical. Thanks

 

[Tony Wells]

You can put a piece of good round stock in the vee and use your standard edge finder to get the true center of it.

 

[Uglydog]

EmilioG,
Tony once again speaks wisdom.
However, please don't be afraid to ask for clarification.

Daryl
MN

 

[EmilioG]

I understand, but an edge finder without a DRO?

 

[Tony Wells]

Sure, they have been around long, long before DRO came along.

 

[Uglydog]

Either an edge finder or a wiggler and hand-wheels. You can account for any backlash.
You'll consistently get .001 or better for a few dollars instead of the $1000 that a DRO costs.
Additionally, all the DRO does is keep track of the distance. You still need to find the edge.

Daryl
MN

 

[kwoodhands]

I'm planing a new Finger Plate for holding small parts and stock.
The hard part will be drilling a through hole after the V is machined at a 45° angle.
The steel plate will then be layed flat after the V cut using an and mill. I need the through hole to
be dead center of the V channel. Is there a way of re-locating that V's center line after it's moved to
a flat position w/o a DRO? If the table and vise are locked, will the drill fall on the centerline after the
part is moved off the 45° angle?

Lay a machine drill in the V temporarily. Pick one that appears to be the same size as the width of the V. Install the drill upside down in the chuck and use the drill to center the table. You will get better results with the smooth shank than with the drill point. Now lock the table, insert spotting drill or center drill. Now you can drill with the proper drill size.
mike