Bob LaCivita replies: To adjust a block plane you must consider what type you are adjusting. Most modern block planes may have one, two or three adjusters.
The first is a depth of cut adjusting screw in the rear under the blade. By turning the knob left or right the blade will move forward or back determining the thickness of the shaving.
Second is the sole adjustment lever under the front knob. Loosen the lever by turning the knob. Move the lever and the adjustable sole will open or close the mouth of the plane. With a combination of depth of cut and a small mouth opening a very thin shaving can be achieved.
The third adjustment is the lateral adjustment lever. This lever when pushed to and fro, let’s you make the blade parallel to the sole. Planes without a lateral adjustment must be made parallel by moving the blade with a thumb and index finger and sighting down the sole.
Wood block planes may need to be adjusted with a few taps of a hammer. By tapping the top of the blade down a deeper cut will result. By tapping left or right the blade can be adjusted parallel to the sole. If the plane has a knocker tap light to back the blade back and tap somewhat hard to take the wedge and blade out.
Garrett Hack replies: Better block planes have a wheel adjuster for depth and a lever for side-to-side (lateral) adjustment to set the edge projecting evenly from the sole. The cap that holds the blade in place should be just snug, so the blade will adjust smoothly. Start with the blade barely cutting and turn the wheel in tiny increments until you get the depth of cut desired. If you go too far, retract the blade some and start over. If the cut is deeper on one side, move the lateral lever to tip that side of the blade back a bit.