It was the three he did on Boring when he was doing that bronze cylinder. He pops the drill gauge in the third of them. He's keen to do more videos....
This morning I attacked the drill gauge. I couldn't bring myself to destroy the old carpenter's square.... If anyone wants a good 12" square, call round, it's yours. I have another one.... I cut the strip to length and milled a slot in the back of the block so it will be flush when fitted. I tapped the block 3/8" Whitworth and decided to use roll pins to attach the two together. Dead easy and plenty strong enough.
Once they were driven home I cut them off flush and filed them.
Here we are ready for the locating point in the base.
I used an ordinary 3/8" set screw and turned a 60 degree point on it. It doesn't need to be hard, its only to locate the tang of the drill.
The point in place and loctited in. What you do is put some blue on the standard and make a mark with the tip of each cutting edge. If they coincide the lands are equal. If not you know exactly how much to grind off to correct it. To check you just smear the blue with your thumb and repeat. Tomorrow I'll get the angle grinder out and polish the standard up a bit.... I love this little jig. Never seen one before and it is so simple and accurate....