That looks like a really nice thread, It can be so hard having to figure it all out yourself.Finally, a wood SCREW!!
Now the dowel I used to make the wood screw was not the prettiest - as it had some knots and almost some bark within it - I figured most likely I would be using it for a testing and not an actual screw for the bench. I took the guild block/nut with the router bolted on top, clamped it to my current bench (hollow core door) and got ready to do my first test. I turned on the router, put my dowel in and started away. NOTE: I had about 3"-4" from my old dowel to use for the initial test. First thing it did was cut the bevel all around the dowel, then it started to advance. I thought, COOL, it is working, It seemed to be turning hard, but I kept going. My thought was "chips" are falling into the fresh cut grove and getting stuck in between the guide nut and new threads. Another thought was the guild block wasn't at 90 degrees causing a binding. I stopped the router, pulled out the "screw" and found that it wasn't advancing correct, only about 1/4" at a time. I wasn't for sure what the cause was, but did something (can't remember what) and tried again with the new dowel. I found it was binding nearly right after I got the bevel all around the dowel. I stopped and looked again. I thought, maybe the depth of the router bit wasn't low enough. Tried that, same results. Stopped for the day and went away to ponder it. Next day I thought, maybe the router wasn't in the right place, too far forward/backward and tried that - same stinking results! I gave up again, left the shop to ponder and research what the possible reason. I studied Carters videos and comments and started to get a thought. I pondered the next day while at church and came up with a possible reason. After church and getting one kid down for a nap while the other watched some TV shows, I went to the shop, looked and tried it out. I put the dowel in with a fresh edge and started the router up. I inserted the dowel and started turning it and realized that it was advancing much nicer than before. I finally saw the screw advancing out of the guide nut. I was SUPER excited to see that. I kept going and once I reached the limit of my setup, I stopped and pulled out the screw out. Below is my results.
Up next - things I've learned.