Drilling and Tapping on Radial Drill

Drilling and tapping four 3/4"-16 holes in a one inch thick plate. I had 40 of these plates to drill and tap so I asked my customer to supply me with one extra plate. I made a drill jig out of it and used a drill bushing that fit the tap drill. I bored the holes in the jig so the bushings fit closely but were easy to remove. Being able to remove the drill bushing allowed me to tap through the jig immediately after drilling the hole.

You may notice the plate sits at an odd angle on the table. This was done so when I swung the arm from, say, the hole closest to me on the right to the hole farthest from me on the right I didn't have to move the head. Essentially the two holes to the right are the same radial distance from the column and the two holes to the left are the same radial distance from the column. It took a bit of trial and error to set up but it allowed me to only have to move the head once per plate instead of 4 times per plate. This saved a fair bit of time and effort.

In my earlier video about my radial drill I mentioned that I liked the depth dial when tapping. I show a close up of the depth dial during drilling and tapping to give an idea of how simple it is.

When I filmed this I was on plate No. 4 of 40 and was still a bit slow. After about 10 plates I was much smoother and got the time down to about 8 minutes per plate floor to floor (or rather, stack of pallets to wheelbarrow).