drilling a hole

round

Depends entirely what you have in the way of equipment. With a drill press you just need to centre the chuck over the bar that has been gripped horizontally in a vice or with clamps. Centring can be done many ways I have a nice gizzmo that fits in the chuck, has a downwards facing pivoted Vee, and two lines - you adjust until they line up. You can use an edge finder, and move over half you bar width. There is a simple version here:

AWEM

Of course, suitable precautions need to be taken to prevent the drill deflecting when starting to drill, e.g., use a stub drill or center drill to start the hole, especially if the drill diameter is small.

Regards, Tony

Easiest way is on a vertical mill. Use what ever centre finding method you prefer. Machine a small flat smaller than the final hole, centre drill, pilot and final drills to size.

1. Fix a piece of scrap iron square bar in the milling vice.
2. Tighten the Y axis so that the vice will NOT move to and from the quill
3. Drill a hole down through the bar of the diameter of the rod.
4. Making _D_A_M_N_ sure that you only move the handle of the vice, rotate the square through 90 degrees so that it is horizontal.
5. Put your round rod into the hole in the square bar.
6. PROVIDED YOU REALLY DID LOCK THE Y AXIS, what you now drill will be SBO (Wiltshire Westinghouse for "Quite Accurate"!)

BUT, how you ensure that the hole is at the right position from the end of the round rod is up to you. (Down to you???)

If you don't have a DRO, one trick is to balance a 6" ruler or similar piece of flat stock on the round, touch the center drill to the ruler, and move the round back or forth until the bit holds the ruler parallel to the table. jsw