The trick is putting a 3" .040 small cutting wheel in a 1/4" shank chuck in a variable speed router. The router needs to be screwed to a 1/8" metal plate creating a flat cutting surface. You slowly grind the grove into the tool steel by pressing down on the steel keeping it flat and running back and forth along the wheel. Grind the very tip after the tempering.
amtek tool and supply sells the cutting wheels and the steel. the tool steel I used is item number ly5000906 9/64 x 2" you can get any length you want.
you need to temper the steel there are a few other tricks to making it work. I'm not keeping a secrets on this it's just not easy. It can be done. Please ask for help if you try it I'd be happy to help.
I may do another demo it takes an hour to show how to do it that's a long recording.
I may try to get my buddy Alex to make a video of it.
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