While working on another project, I got somewhat frustrated with how it was not coming together as I had expected, so I took a break from that to try this. I’ve been meaning to do this for a while, but hadn’t found the time and, to be honest, I didn’t think it would work well anyway. So, with nothing to lose, I set up the very simplified rig that you see here:

Basically, just a 4×4 block clamped to my miter gauge and set at 45 degrees. There’s a 1″ hole drilled through the middle, near the end and the table saw blade is cutting part of the way into it.
The idea is to cut the stock that will be turned into dowel to 3/4″ square, chuck it into a drill and run it through the hole. The spinning blade will do the cutting, while the 1″ hole supports the stock.

The first step was to turn it by hand to reduce the end enough to fit into the drill:

With the drill spinning it, the cut was a lot smoother than I thought possible. Not only that, but also very fast and remarkable even. In the demonstration video at the bottom of this page there are some ridges that can be seen, but that is from stopping the cut to change the camera position.

I cut a longer one and it’s amazingly smooth and the diameter is consistent along its length:

The end of the long piece that was turned down to fit into the drill. A better way to drive it would be to drill a 3/16″ hole into the end for a hanger bolt chucked in the drill.

As shown in the video, there needs to be something on the outfeed to support the as it exits the cut, and by making that with a hole of the desired size, it would act as a gauge for setting the jig to the correct diameter:

I figure dowels from 3/4″ to 1/2″ could be cut on this with a 1″ hole and 3/4″ stock. Reducing the hole to 1/2″ and the stock to 3/8″ square could produce dowels from 3/8″ and thinner. Of course, really big dowels could also be made – 1-1/2″ or 2″ are entirely possible.
At some time in the future I will revisit this and make a more permanent version.

I made a really short video showing it in action. Note: there is loud, obnoxious music, so you might want to reduce the volume: