[quote="greggy"]for safety reasons, ie if you have a gap too big then there is a greater chance of the timber getting snagged in the hole/gap and you then put more force on the wood and get your fingers ripped apart.
the smaller the gap the safer. i would replace your home made one with a proper one that icludes the reducing rings,like trend, incra, kreg etc etc.[/quote]
Yeah thanks for taking the time to reply and I would have bought a manufactured one had I the money to so will be making a top up with a smaller hole for smaller bits I mostly use and keep the large hole one for the large bits on the rare occasion they will be used.