If you have 1/2" bore sprockets, gears, or hubs on hand, you can use one of
these to allow you to mount it directly to the output shaft of the PG27.
A hub could be an easy solution for mating with larger diameter PVC, which you can step up or down to the diamater you want for your intake using commonly available parts from hardware stores.
You can also try something similar to how BoomDone mounted their PVC rollers to their versaplanetaries.
http://www.chiefdelphi.com/forums/sh...7&postcount=53
Although, this method may not work as well with the 1/2" round output shaft of the PG27 as it does with hex shaft.