Drilling Square Holes

March 17, 2009

Last week I used the old Mortise machine for the first time. When I say old, I mean that it used to be powered by a water mill and that there are more leather belts on this machine than under the hood of my car. I’d been watching Peter use the machine for the last few weeks but was never quite sure exactly what it did – besides for making a lot of smoke. Getting asked to use the machine felt like graduating to a new level of responsibility.

In a nutshell, the machine drills square holes in order to create a mortise for a furniture joint. In theory, the square holes are drilled in sequence to create a straight hollow line. The straight line corresponds to a matching tenon and the joints line up and fit. Two pieces of wood become one without any nails or screws. It is simply amazing. The ingenuity behind this old machine makes me bow my head in respect.

And how do you drill a square hole you might ask? This is the part that is so amazing. A regular drill bit is enclosed in what is effectively a 4 sided chisel. As the drill presses downward and creates a circle, the circle’s perimeter tangents are hit with the chisels. Then end result is a perfectly crisp square hole. Amazing.

After doing a bit more research on the history of the machine, I learned that it from the company Wysong and Miles Co and it is model number 272. It was originally a Line Shaft machine that had been converted over to an electric motor. For more detailed information on how Line Shafts work, please visit this excellent post. There is a decent photo gallery of old Wysong and Miles mortise machines at the Old Working Machines website which can be viewed here: I copied the following photo from that gallery. As an explanation, the first thing to notice is the giant foot pedal. This is used to push the square chisle through the wood while drilling. The next thing to notice is the large bottom wheel. This sets the depth that the mortise will drill to and finally, please note the smaller nob near the fence. This sets the distance from the edge that the line will drill to. Like I said before – simply amazing.

For more information on master furniture techniques and designs, please visit

Cold River Furniture.