I had a boring weekend in the shop. Boring bars, that is.
I really like the 3/4" stainless steel boring bars that came with my Monster hollowing rig. However, they're limited to working through a 7/8" or larger hole, and I wanted to be able to go smaller. Over a year ago, I bought a set of Don Pencil "Stinger" 7/16" boring bars. They were a nice size, but I never did like the round bar cutting tips that came with them. Plus, the set screws to hold the cutters were tiny, and they stripped out way too easily (or my hex wrenches twisted because they were so thin).
After reading about several guys recently making their own boring bars and Oland tools, I figured I should give it a shot myself. I wanted 1/2" bars that were capable of holding the 1/4" cutters that I already had for the Monster rig.
Saturday, I picked up a 3' piece of 1/2" cold rolled steel bar and a few set screws at the local hardware store. The first three bars went so well, I went out Sunday and bought another 3' piece of steel and made a few more. Here are a few progress pics...
First, I had to figure out how to drill a hole in the end of a 1/2" steel bar. I took a wooden screw clamp, and drilled a 7/16" hole between the two halves of the clamp.
Attachment 30144 Attachment 30145
That allowed me to hold the bar vertically and drill a pilot hole...
And then the final hole. (I don't know what size it is...I just experimented around until I found a hole size the 1/4" square HSS bits would fit in.)
Attachment 30147 Attachment 30148
Then, to hold the cutting tip in place, I needed a tapped hole for the setscrew. I ended up using a 10-24 screw, so the pilot hole was a #25 bit...
I also wanted to make a bar with an angled cutter, so I ground an angled flat spot on the end of a bar and drilled a hole to fit the cutting tip...
Attachment 30149 Attachment 30150
The angled bar also got a setscrew, but I didn't get any pics of that operation.
I also made three different bent bars (with a little help from my propane torch), but didn't take any pics of the bending process.
More in the next post...