The last major bit of our stepstool is to make the axle that the legs rotate around. This is a piece of hickory that I had. Hard to beat the resilience of hickory for something like this, though ash comes a close second (there’s reason that those two species provide the hafts for almost all the tools out there). It’s a bit of a stretch for the bearings on my old lathe, but I manage.
Now I go ahead and drill and countersink the pilot holes for the screws that will actually hold the stool together. The specification was for brass screws, but I prefer to rely on the greater strength of steel ones, even if they aren’t as glitzy. Be sure to use a reliable depth stop when you’re drilling into the legs so that you don’t poke through the edges.
Finally, I depart from the specification in a minor way by putting a bullnose profile on the steps. The square edge is just unfriendly to my mind. I use my #4 smooth plane for this. It’s faster than a rasp, and there’s less sanding afterward.
Actually assembling this stepstool is a bit of a thought exercise. You have to put the axle inside the front legs at the same time as the bottom step, then attach the back framework around the front assembly, finally attaching the top step to cap off the whole thing. You wind up thinking that you were definitely, definitely shorted a couple of hands. But it is doable. Once it’s together, you will need to level the feet. Be sure to bevel the bottoms of the feet once you level it off so that they won’t splinter.
A note on finishing. Given the complexity and overlapping nature of the mechanism, it’s easier to sand and finish before you screw it together. Also, because you’ve got parts rubbing against each other, a film finish (like shellac) or paint are not good candidates for use as they will bind up. I used an oil finish here and it keeps everything moving smoothly.