Originally Posted by Lost Sheep
Alternative is to get a machine screw/bolt that fills the inner diameter of the dipper you wish to adjust. Drill a (slightly undersized) hole straight through the bottom of the dipper and thread the bolt into the hole. The bottom of the dipper can be adjusted up and down by turning the screw/bolt. It you used a hex head bolt, you have to do this from the bottom. If you used a screw with a round head, you could do it from either direction.
Good stuff there. You can also fine tune a dipper by drilling and tapping the bottom for a setscrew. They don't add much weight or stick so far out the bottom.