Firstly I took an old piece of MDF that was once a set of shelves, then a speaker box, and now wasting away in the garage and cut two pieces out. One was 5″ the other 4″. It took about 10/15mins to get through the MDF, I thought the drill bits were a bit crap but I think the drill itself is probably still underpowered. (it was quite a cheap unit when I bought it) Also I found it was very easy to get on an angle, possibly the density of the wood was different nearer the edges but I found it was digging in quite a fair amount on one side or the other and I ended up with not very even pieces. The first one wasnâ€™t so bad but the second significantly skew. I will borrow a drill press to try and get a better piece, at least until I build my own later.
I put a bolt down the center shaft and tightened it up and placed the bolt into the chuck of my drill, then mounted the drill in the vice. To get foot control I tied a rope around the trigger, which travelled along my workbench to a nail then down and tied to a metal ruler/level at a height where I could push it down to pull the rope and as such, pull the trigger. I had some control over speed, but it could definately be improved.
This is how it came out, I was quite happy with this result.
I built a second but it came out quite skew, I will use a drill press to re-cut the MDF, and if its faster than the hand drill I might cut two circles, and stick them together to form a bigger pulley. something like so:
Update 12 July 2010
I also refined my drill/lathe technique a little over the weekend. I think I will modify it further to become a slightly more permanent fixture with a bearing on the other side. because its only fixed to the drill its quite easy to push too hard and bend the drill which alters the shape of the turned wood. to start with I may just buy a 30cm peice of threaded steel, grind myself a nice 3 sided head on one side so that it fits into the drill nicely, and smooth the otherside and it can sit in some sort of fixed socket to provide a more stable shaft.
I also built the new pulley, twice as wide so it will accomodate more reasonably sized belts.
Currently my plan for the belt is to use rubber from an old push-bike inner tube