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Hey Al, There's a really neat and simple way to do it. A picture would tell the story in a second, but I'll try to describe it anyway. Use 1/8 x 1 steel and bend one end in a semi cirle so it hooks onto the boring bar (ie the semicirle needs to be the same size as the bar, or close, not rocket science). It should look like a "J". Make the straigh part of the J about a inch or so longer than roughly how far out you want the bit to stick out. Then make a 90 degree bend towards the bar and cut it off so that little straight part is about the diameter of the bar. Drill and tap a 1/4 x 20 hole so if you thread a bolt through it, it will hit the cutting part of the bit. To use this simple little tool, just hook it (by hand) onto your bar and thread the bolt up to the end of your bit. Using a 1/4 x 20 bolt means one turn of the bolt is 1/20", or .05. One half turn is .025, 1/4 turn is .0125, 1/8 turn is .00625. You could easily figure this out using a 1/4 x 28 or whatever you want. So, make a cut, measure the hole, put your little device on, snug up the bolt, back it out 1/8 turn (or whatever), loosen the bit, advance it to the bolt, tighten the bit, remove the device, make a cut, see how much you cut compared to how much you thought your were going to (they won't be the same due to spring in the bit, flexing of this and that, whatever). Start inching your way up to size. Neat trick. If you could braze a nut on instead of tapping only a 1/8" thick piece of steel it would be better, hopefully you get the idea. Let me know you can figure it out with this description. It's a piece of steel that looks like a J, with a little bolt threaded through the serif. Tools
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