What is a Mother Plane?

I get asked all the time at events where I demonstrate my planes - "How do you cut the profiles on the sole?"

The answer is easy...well, sort of. :) I start by making a plane that is exactly like I want my final production plane to be. I call this my prototype plane. I cut that profile with hollows and rounds along with rabbets and/or plow planes. However, I don't want to do that for every plane I want to make in the future because it would be tedious and take a really long time. Therefore, I use this prototype plane to make a mother plane which is essentially a "negative" of the profile I want.

I can then cut multiple plane soles with this mother plane, all of them being virtually identical. These planes that are made from the mother are then called daughter planes. It is a good process but it is tricky to make a good mother plane. It involves making planes with multiple irons in order to cut these mucho complex profiles.

I have been making these mother planes for quite some time now, and was thrilled to discuss them with Bill Anderson recently. He is in the process of studying a very large collection of antique mother planes and he told me that the original makers would typically combine multiple dedicated planes to make complex profiles rather than putting multiple irons in a single plane. I can see some advantage to this, but also some disadvantage. I may try this in the future for some other profiles, and look forward to seeing more from his research down the road.

Anyway, I put together some videos of the process. The first is a time lapse of the process and the others are the full, comparatively slow process. I hope you enjoy seeing how this is done.

Also there are a few of these Ogee and reverse Ogee planes left in the shop.