Thank you all for the nice comments.
Hi Eric, you can cut threads on a wood lathe. but you have be quick to follow the pitch. You can use a standard V bit to cut them on a metal lathe but that is just a scrape cut and you can get a lot of tear out. with the cutter spinning fast, you get a cleaner thread. I am still looking for a carbide 60 degree  V bit with a 1/8" shank. I thought I had a company to make me one last winter but they backed out and said they could not do it. the cutter I'm using I made from tool steel and it is not the best.
Hi Bruce, I found this model of a Dremel to have a straight consistent diameter for about 1 3/8"- enough to get a firm hold on it and not crush it if it were out of  round like some of them are. I had a V- shaped holder but it put too much pressure on just 4 points. I threw it away after I saw how this one worked.

Hi Alex. To do the threading with the Dremel you need to use a metal late with a lead screw that creates the pitch you are cutting. It can also do nuts and the inside of lids to thread onto containers. That 3D printing is cool but there is not enough mass there to hold it steady. you could make a thicker one, I suppose. The maple block is rock solid when bolted down to the compound and I'll bet it was a whole lot faster to make.... just a few measurements and no programming. I'm an analog guy so I work without the computer...just a calculater with Trig on it. ( it is faster than a slide rule)

Cheers, Jim

Cheers, Jim ........................ Variety is the spice of life...............Learn something new every day