Monday, October 20, 2014

On The Bench: Classic Boston Rocker

To celebrate the coming of our son, I wanted to make something special, something we could all enjoy, and something that could be passed down. After talking about it with my wife, we came up with the idea: a classic Boston rocker! (Actually, to her credit, it was her idea. She's always full of great ideas!) I was very excited, this would be the perfect project! Something beautiful we can use while he's young, and when he grows up, we can pass it down to him to use with his children.

And then the excitement turned to dread...How the heck am I gonna build this? I've never done a chair before, let alone a Windsor-style rocker (supposedly one of the more difficult of the chair designs)! What dimensions does the chair need to be? What angles do the legs need to join with the seat? How far back should the back posts go? What radius do the rockers need to be cut to?

I haven't been one to enjoy building projects from a pre-made plan. I like coming up with my own plan, perhaps a variation on something else. But without something to start from, the project seemed stopped before it even got to the design phase.

Googling around, I managed to find this plan from Woodcraft, which as a preview, had a cut list and a picture. Not really wanting to buy the plan itself, I started to try and design the chair from the picture and the cut list. This got me most of the way there — I had by the end of it a Sketchup model of what looked very much like a rocking chair. However, I still had no idea of the dimensions of the chair were correct, or the angles, or anything. It's kinda hard to sit in a 3D model of a rocking chair...

Profile of my parents' rocker.
Fortunately for me, I was about to take a trip to see my family for a week, and they have a Boston rocker they bought when I was young. Perfect! I can measure that rocker and design my chair based on the dimensions from that! I took lots of pictures and measurements of the chair — everything from how thick the spindles were to their angles and offsets. I took profile pictures for the back crest, arms, and rockers so I could clearly see their shape.

When I got home, I eagerly took those measurements to my Sketchup model and found that my original design was rather severely off in a lot of ways. But it was close in other ways too!

Sketchup rendering of my rocker.
With some modifications, I had my final design! The rockers and back were all pulled almost straight from the picture (I liked the style of them much better than what I initially came up with). My chair, unlike my parents' chair, would use straight spindles for the back, not curved flat slats (I felt I was learning enough on this project as it was, and didn't need to also learn to steam bend).

Knowing now that the rockers were the correct shape, and the dimensions work for a very stable chair, I began eagerly cutting wood.

I decided to make the chair out of solid American Black Walnut, and managed to find some really beautiful wood at the lumberyard. Before I could really start though, I needed some more tools (of course)! I had never done anything nearly as curvy as this chair, nor had I done anything with spindles. So, I needed a bandsaw and a lathe.

After some careful deciding, I ended up with the Shop Fox W1706 bandsaw, and the Excelsior Mini Lathe, both of which I got with risers / extension beds. These machines are beautiful and cut very very well.
Rocking chair pieces (center).

As I'm finding, cutting the wood for this project is most of the work! I've got it almost done (roughly), but still have yet to cut the arms or the spindles for it. All of the other spindles are at least round, but I have yet to cut the tenons, or the decorative shapes into them.

I think cutting the back crest was the single most scary thing I've done. Again, not wanting to learn steam bending, I decided to cut the curve using the bandsaw and some really thick wood — a 4" x 6" x 36" chunk of solid walnut (yow that was expensive!). Actually making the cut wasn't the scary part — it was the thought of messing up and ruining that huge chunk of wood!

From the Sketchup model, I created templates for all the pieces, including the back crest. For that, I had two templates — one for the curvature and thickness of the piece, and one for the shape of the front. I laid out the curvature template on top of the block of wood and carefully transferred it to the wood. Then, to the bandsaw! Very carefully, I cut the curvature, slowly following the line. I feel like I must have been holding my breath the entire time, because when it was over, I took a huge breath of relief! The cuts came out perfectly, and even better, the wood grain exposed by the cut was unbelievable! Two knots at either end of the crest give wonderful radiating grain lines into the center and back out. I certainly didn't plan for this, nor could I have — these grain lines weren't visible on the outer surface of the block. Couldn't be happier!

Another quick trace of the front pattern and cut on the bandsaw, and I had the rough shape of the crest all done. A pass on my spindle sander (e.g. drill press with sander bit) cleaned up the jaggies on the edges left by the bandsaw, but I still have some smooth-sanding to do to make the coarse lines from the spindle sander go away. The front and back faces I sanded with my random-orbit sander and some elbow grease with a block sander. None of this is finish-sanded, but at least the machine marks are gone.

Next, more smooth-sanding of the crest, and cutting the arms and arm-support spindles! ■


  1. This project is really cool! Can't wait to see the finished product! :D

  2. Amazing work! Can't wait to see the finished product! And maybe even rock my grandson in it?