When fashioning a custom ground cutter for any profiled cutter for a hand plane, the cutter profile needs to be an elongated version of the desired profile. In the example below, we want to create a specific profile (indicated in red). If we simply ground our cutter to the exact profile as the desired profile, everything would be fine if the cutter was oriented perfectly vertical relative to the planing surface. But, a plane like that would not cut well, which is why we have bed angles on planes. If you put that same profile in a plane with a 52° angle from horizontal, like the Stanley 45 and 55 planes, the profile would end up being flattened out. Therefore, you need to exaggerate the profile.
Here are the steps needed:
- Create an XY axis.
- Trace your desired profile in the left upper quadrant. Note that the profile (in red) is turned 90° clockwise from its typical orientation.
- Draw a 52° angle line in the left lower quadrant (corresponding to the bed angle of your "55" plane).
- Transfer key landmarks of the profile vertically to the 52° angle line and horizontally across to the right upper quadrant.
- Swing arc lines from the 52° angle line to the right side of the horizontal axis using a compass centered on the xy intersection.
- Draw vertical lines from where the arc intersects the horizontal.
- Rectangles will be formed. Draw faint lines from one corner to another in each "box" corresponding to the desired profile
- Smooth out the connecting lines as needed.
Note how a traced arc at the top of the drawing shows the amount that the profile of the cutter needs to be lengthened due to the bed angle. Also note that the cutter orientation with the slot for the cutter adjustment knob is traced in bold. Hopefully, this makes sense.
|A couple of custom profiles for the Stanley 55 plane|