How is this edge finder an "audible" indicator?

[RaisedByWolves]

I am aware of that method of locating the intersection and use it myself. In my experience, even the lightest scribe line is multiple thousandths wide. When he says perfectly located, what does that mean? He verifies with a loupe. I had done some work in the past where I needed to visually verify position to better than a thousandth with a 50X microscope and that was difficult enough.

However, a good R&R study would demonstrate just how accurate that or any other method was. For my part, I have a 300X microscope that I can mount in the spindle of my mill and in conjunction with the DRO, I can verify positions of features to +/- .0001". I would scribe a series of intersecting lines and center punch the them. The I would locate the coordinates of the scribed lines and the center punch marks and compare.

You're talking about picking up a scribed line.

How accurate is a scribed line to begin with? If you're looking to get closer that a 64th (.015) then scribed lines are not the way to go.

 

[ChazzC]

You're talking about picking up a scribed line.

How accurate is a scribed line to begin with? If you're looking to get closer that a 64th (.015) then scribed lines are not the way to go.

I would hope I could get closer than 0.015” scribing a line parallel to a side of a block using a height gauge & surface plate.

 

[RaisedByWolves]

I would hope I could get closer than 0.015” scribing a line parallel to a side of a block using a height gauge & surface plate.

Right, but in general that method won’t fit every situation.

Trust me, I get funny looks in the shop laying out projects sometimes, but if the end result works…

For anything approaching square that will fit on the mill, picking up your X-Y corner and going from there is just simpler and better all around, but for clearance holes, bolt holes there’s lots of wiggle room.