It took some time with a tape measure, some mirror angles, and goofy positions to accurately measure my own armpit from front to back. Granted, I was building this for my dad, but come on, there was no way I was going to ask to measure his armpit. No way.
Keep in mind that if you attempt this project, the whole goal here is to connect your armpit to the ground so your leg doesn’t have to anymore. If you’re going for custom fit you can make this part as custom or as standard as you please. I was on a one night type of deadline so I chose a more “what’s comfortable for me should be comfortable for you” approach. We’re approximately the same size/height/build however you want to refer to it, so I figured I’d be okay to assume the same armpit support length.
With the idea that it all starts at the armpit, off I went. I took the rough stock and freehanded what I thought was an aesthetically pleasing curve onto one side of it. The main curve went from the full 2″ height down to about 1 5/8″ height down in the center by the time it ended up a finished product.
I then marked out where I wanted to have the sides attach and the respective mortises. The mortise locations depend on the thickness of the stock, and how wide I wanted the handle area. I usually allow 4 1/4″ for any handle that I make for a comfortable grip and this case was no different. For those of you following along, 4 1/4″ + (1 3/8 X 2) = 7 which would be the very outside marks on the armpit piece. The very inside marks would be placed at 4 1/4″ and each one is 1/2″ thick. These are all with respect to center of course. (Refer to picture 2 of this step) This layout would also allow for an 1/2″ overhang on the armpit piece which is kind of what I was going for and why it was cut at 8″ length to begin with.
I wanted to try out some mortise and tenon joinery on this project just because I haven’t tried it yet and I thought it would be really simple to assemble in the glue up stage. Spoiler alert: Pretty sure this may count as a traditional mortise and tenon fail because they all go full width of the stock, but I’ll get back to that in a minute.
Once I had everything marked out, I roughly cut the curve out with my jig saw and promptly set my router up to remove the bulk of the waste for the mortises. I’m using a 1/2″ straight cut bit with my edge guide to do this. This was a first for me was using the edge guide. It was a bit tricky to setup but after some fiddling I finally got the hang of it. I just used the layout lines to eyeball the bit into alignment with the slot I wanted to make.
After that was done, I put the armpit piece in some parallel clamps secured to the top of my table saw and went about cutting my mortises. This was all done in 1/4″ depth increments with the plunge base. My plunge base has a stair stepped depth stop so, once set up to the initial depth on the top step, you can drop it in 1/4″ increments 3 times. This gave me a 3/4″ deep mortise 1/2″ wide. Unfortunately, I marked out and cut the length of the mortise equal to the entire width of the stock so when put together, you can faintly see the edge of the mortise on either side. Not a deal breaker, and certainly not that important in this case, but guaranteed I won’t make that mistake again unintentionally. Embarrassing.
