Thanks guys,
Yes i agree that the wedge needs to have some sort of adjustments, and it will be mounted so that this can be done in both axis.
I probably forgot to mention that earlier.
Actually i found an alternative design called (The Mrttler Wedge) at this site.
http://members.aol.com/planclos/index/mettler.htm, reckon i might be able to follow this sort of design.
cheers Leon