If I had a digital camera, I'd show you mine which I recently completed. I think it'll solve some of your problems about getting the shafts to spin perfectly -- and I've only got $24 in mine!

Here's a link to the basic plans I started from: http://www.stickbow.com/stickbow/arr.../cresting.html

I took a board to use as the base, then attached guide rails to it so I could slide the "V-block" up and down it to accomodate for shaft wobble -- just as the instructions show. I did modify the plans though, by using a solid-oak block for the v-block, but I didn't make it a traditional v-block. I drilled a hole the exact heighth I needed slightly larger than the arrow, which holds the arrow from all sides. This allows the arrow to spin freely, but securely as well.

I got a sewing-machine motor for $5 at a repair shop. I then bought a $12 fan speed control switch, and wired it to the motor's plug-in to bring the speed down (those little babies hum!).

My final expense was ordering Bohning's replacement chuck from Kustom King archery ($7). I liked the idea of attaching it "properly", like it was designed to -- rather than using surgical tubing, which I anticipated to be very contrary.

Hopefully I can get pics of it up sometime, but it looks great, and you can dial up the speed you need -- while having both hands free to work on your cresting.