Introduction: Cross Hole Drilling in Round Rod Stock
Repeatedly bore accurate holes through metal, wood, plastics or other round shapes with this simple method and a drill press. The principal is quite straightforward; easily find the top dead center (T.D.C.) of a round rod, usually a difficult task without specialized tooling. This tip readily allows the use of a common rectangular drill press vise, hand screw, or simply wedging the round work between two parallels to hold it fast while finding and boring T.D.C. To clearly demonstrate the principal I used a shop made "V" block which would suffice by itself for this task.
Step 1: How to Setup
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 against the setup and observe the flat for parallelism to the fixture.
Step 2: Finding T.D.C.
Adjust work and fence to make the flat parallel, thus top dead center is found. To complete, spot drill, bore to desired diameter, repeat as described below if needed.
Step 3: How to Do Serial Drilling
Fasten a deadweight- I used a handscrew- through a previous bore, let free hang to ensure a vertical lineup of sequential holes for boring.
Step 4: Why Do This?
Cross drilling the end of a shaft is commonly used for economically retaining bearings, wheels, spacers, etc with cotter pins. A more demanding use is to insert a roll or dowel pin to transfer rotary motion such as driving a wheel, engaging a clutch, cam, or other mechanical connection.