rx7locost wrote:
Assuming we are talking about a drill press, and not a hand drill: A good solid vertical center punch is key. .
Yup, been doing it that way for a good long time. works great in steel, gotta be a bit careful on the softer metals, as you can absolutely move the center if the punch isn't held perpendicularly to the surface.
I also always ap-ply a bit of Geometric tolerancing philosophy: A .015 geometric hole position is reasonable and within 6-sigma, and mostly, about as tight as the average home builder can do reliably.
I also don't clamp the workpiece to teh drill press table. what I do is lower the bit onto the centered dimple, and then, by hand, turn the chuck backward to let the bit center the part.
as far as using papaer templates glued to the workpiece? naah. measure and scribe. paper just gets in the way. IMO.
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The B-3 build log:
http://www.locostusa.com/forums/viewtopic.php?f=36&t=13941 unfortunately, all the pictures were lost in the massive server crash
The beginnings of the Jag Special,
https://www.locostusa.com/forums/viewtopic.php?f=36&t=19012Again, all pictures were lost.