If your spokeshave is secondhand, check the angle of the bevelled edge using a protractor. The bevel should be no more than 30°.
To set the cutting iron depth, use the two adjusters one at a time to lower or retract the blade until it looks parallel to the sole of the spokeshave when looking along the sole of the spokeshave from the front edge. The more blade is visible, the deeper the cut will be. To test out the depth, use a long thin piece of wood about ½” thick, take a shaving from one side of the blade and then using the same pressure take a shaving using the otherside of the blade. If the thickness of the shavings are similar, this means that the depth of the cutting iron is similar on both sides. If the shavings are different, adjust one side until they match.
The angle at which you present the blade to the sharpening plates is important because if it is too steep, the cutting edge will be higher than the heel of the bevel, which prevents the blade from reaching the wood to cut. Using the same tools and techniques as sharpening a chisel, you will be using the 3 different sharpening plates. Like sharpening any other blade, you want to ensure the angle of presentation is correct to allow you to create a camber on the bevel. To do this, make sure when you are sharpening the bevel on the plate to slightly lower your hand so you finish on the heel of the bevel. To create bevelled corners to each side of the cutting iron, tilt the blade slightly onto the corners. This bevels the corners which means you don’t leave harsh lines in the surface of the wood when cutting.
To read more on spokeshaves, we recommend the following from Paul’s blog: