I stopped by Harbor Freight and picked up the calipers, step drill bits and a wood rasp set.
This morning I set up my drill lathe with all the tips everyone has given. I bored a hole in the oak block that the head of the carriage bolt fit
in and then I lubed it with a few drops of oil. I also attached the vertical board to act as a tool rest. I used the wood rasp, a chisel, and sandpaper to shape the popular. I used the caliper to size it to match the booster body tube and the sustainer body tube.
I like the way it came out. I do have a few areas to fill with but overall, very uniform.
Next was to bore out the center. I used two of the step bits to do that. The smaller one drilled a 3/8" hole and the larger one a 3/4" hole but that was the size all the way thru. It's a cone shaped bit and it would only go in so far so I drilled from both the top and the bottom. I did that with fear that it was all going to go wrong because I was holding the transition with my hand while doing the drilling. I just couldn't figure out a way to clamp it down...
The 3/4" drill was actually .750 and was not quite large enough for the ST-7 tube to fit in. I measured a 3/4" spade bit and it was slightly larger at .768 inch. TO avoid tear out, I open up the hole (top and bottom) with a sanding drum on my Dremel. That allowed the bit to go in a little before it started to drill. I had to go in from the top and the bottom again and this was even scarier than drilling with the step but. The step bit was pretty smooth but this bit vibrated the wood quite a bit and I was afraid it would be ripped out of my hand and destroyed. But alas, my fears were unfounded. I ended up with a pretty uniform hole bored thru the transition that the ST-7 tube will slide into, albeit a little tight, but it goes in. A little sanding and it will be perfect
A little detail work and it'll be ready for the rocket.
Thanks again for all the advise,
-Bob