HANK METZ
04-29-2014, 12:25 PM
While the method depicts metal as the material being drilled, it is the same means of boring serial holes in wood or other round products, this just happens to be parts of a DIY CNC machine tool I’m making and thought I’d share it after a very successful and accurate outcome. The principal is quite straightforward; find the top dead center of a round using a simple shopmade “V” block. Spot drill, bore to desired diameter, repeat as described below.
Step 1 is to obtain a short piece of flat metal to serve as the indicator, and a centered pointer of appropriate size to act as a fulcrum. Apply slight downward pressure of the quill and observe the flat for parallelism to the fixture.
288348
Adjust work and fence to make the flat parallel, thus top dead center is found.
288349
Fasten a deadweight through a previous bore, let free hang to ensure a vertical lineup of sequential holes for boring.
288350
Just a note in closing, this method resulted in my aligning a pair steel rails for the “X” axis of my machine with about a 3 thousandths (.003) deviation over the 24” length.
Step 1 is to obtain a short piece of flat metal to serve as the indicator, and a centered pointer of appropriate size to act as a fulcrum. Apply slight downward pressure of the quill and observe the flat for parallelism to the fixture.
288348
Adjust work and fence to make the flat parallel, thus top dead center is found.
288349
Fasten a deadweight through a previous bore, let free hang to ensure a vertical lineup of sequential holes for boring.
288350
Just a note in closing, this method resulted in my aligning a pair steel rails for the “X” axis of my machine with about a 3 thousandths (.003) deviation over the 24” length.