we do staff sparring and sparrings competions a lot in germany. We have decided to go the way over a padded weapon. Sorry at the moment i ve just a slovak description how to build a safty bo.
http://www.kobudo.sk/boshiai.html# and then press Výroba zbrane na bo shiai.
My teacher has a long experience with staff sparring, he first did it in an kendo bugo and real staff that had been some where in the 80's. Then he had gone the way and has a real stuff and put it into a pipe isnsulation. That had the disadvantage that it had been to big, but we could fight without protetive clothes. The next step had been to use an alumin pipe in an pipe insulation. That kind of safty bo had been thinner and much faster, but wiht this type the injuris got much more. So we change it to a PVC-pipe inside. With this we got much less injuries but this safty could break, but better to break the safty bo as to break a bone.
Here are some of the fights:
http://de.youtube.com/results?search...rch_type=&aq=f