Very Cool! Tandum builds are awesome. Is on my list.
I didn't know you had to cut down the shaft. How did you do it? Did you already say and I missed it?
Gonna look but there were a couple of tandem builds here from way back. They were uber cool. One ("Frankin-bike" or some thing like that) Looked like you could put some one on the back seat and go cross country. No kidding the set up and seating looked that comfortable.
http://motorbicycling.com/forumdisplay.php?f=44
tandem - Google Search
Dang it! Now ya got me wanting to go buy the Schwinn tandem! Schwinn: 2009 Tango Tandem lol
Forgot. Thanks for the grinder tip. I was gonna make a thing so a saw blade rested on the spinning shaft. Yours sound much better