But the carbide tipped ones are basically a tool handle with a steel shaft and a replaceable carbide cutter that attaches to the tip with a screw. I can make a tool handle. A piece of 1/2" square bar stock will serve as a shaft. All I really need is the replaceable cutter which, as luck would have it, sells for about $20.
I turned the handle out of soft maple. I drilled the end out to accept a piece of square bar stock, which I epoxied into the handle. I used small pieces of copper pipe as ferrules. Most people who make their own handles for these, cut a recess in the tip of the bar stock, so that the top of the cutter sits flush with the top of the shaft. I don't see the necessity in that. I just set my cutter on top of the bar stock. I drilled and tapped a hole through the top of the shaft near the tip. Then I marked the outline of the cutter, so that I could remove any excess material from around and under the cutter's edge.
That's really all there is to it. Turn handle, insert shaft, add ferrule, drill and tap, shape tip, attach cutter. Done.
Having used them a few times, I'm not really all that impressed with them. I won't count them out just yet, but so far I like using traditional gouges better than the carbide tools. I guess I'm just Old School.