For the Sake of Clarity

I've been turning my thoughts towards the class that I'll be teaching at Kelly Mehlers School in a few weeks. I thought it might be worth highlighting some recent thoughts and plans for the class.

Let's face it, there are enough chairs in the out there. I don't rush to the shop concerned that someone is lacking a place to sit. I go for the joy and challenge of making. For the most part, the chairs that I make leave my shop  and I am left pondering the next chair, my tools and my process. As I assume it is with most folks, it's about exploring the limits of my tools and my ability.
And as do most folks, I've looked for help. The magazines and books guided and inspired me, but in the end, I was left guessing whether my results were hitting the mark. The funny thing is, even after all these years, the desire to get more from my tools and process has only deepened.

A case in point just pulled up as I was writing this. My friend Scott came over last week and I helped him reshape his turning tools. This time he came over for a couple of chunks of maple to try them out on. He was remarking how excited he was to get back to the lathe now that his tools were better shaped. I know well the frustration he must have felt turning before.

In a broad sense, this is what the class at Kelly's is about. We will investigate the geometry and function of tools we have and ones that we are making to get the most out of our woodworking experience.Whether it's the holding power of our shave horse or the angle of the handles of our drawknives, we'll be  addressing our expectations head on.

One project that I am excited about is making adzes.
Tim Manney and I have turned our attention to designing a new adze.
Tim had great experience in Peru watching the folks use adzes and I've always made my own adzes, first for financial reasons and lately because I haven't been impressed by the ones available. And, oh yeah, did I mention financial reasons?

Grinding the Blade

We've been asking the basic question "What is a proper chairmakers adze and how does it work?" I've come up with a good prototype and Tim and I made up some variations hoping to advance the design and better understand its use. As expected, our initial efforts raised more questions than answers, but we have gotten some great results and are looking forward to the next versions. Greg is bringing along his forge and anvil to Kelly's so we can make some tools, including adzes and start at the beginning of our craft, the steel.

A Rough Prototype

On the process of chairmaking, we'll start with my basic goal as a chairmaker.
I don't want to make a chair, I want to make any chair. That means that I am not satisfied to have a single design, instead, I want a process that functions to bring to life whatever I can imagine. The Windsor technology is a perfect framework for this, as the limitations that it offers have led me to come up with some simple landmarks and techniques for connecting the dots.
Chairs can be mysterious, even to experienced makers, but I think that with a little focus on design and process, you can understand the variables and their meaning.

A Chair Near Completion

I won't ramble on any more, suffice it to say, this is going to be an exciting week and I hope to see you there.

Dialing it In

I successfully used the new rocker routing fixture to cut the slots in the walnut chair that I am finishing up.

I suppose that a quick word is in order about my reasons for going to the trouble of building this tool. While I enjoy doing many things with hands tools, because they give me lots of control, freedom and results that machines can't match, when it comes to rockers, I have a different priority.
Designing and building rockers is a process full of variables. To rock successfully, rockers must be oriented to each other and the chair correctly. Any variation in the process of cutting the slots and fitting the rockers can make it difficult to refine the design. Also, the references used to locate the slots can greatly affect the consistency from chair to chair.
What this fixture does, is create repeatable and consistent rocker slots based on references that allow me to focus on the other variables that go into making a rocker.  For me, nailing down the relationship between the seat and the rockers is the next step towards a deeper understanding and freedom in rocking chair design.

I am going to show some photos here, and hopefully you can see that while it has some adjustable parts, the fixture is simple and does a simple job. The photo below shows one the primary advantages of the fixture, which is that the two platforms are automatically parallel to each other which insures that the slots are as well.

Here are the slots already routed. The straight edge lies dead flat against the inside of the slot on both legs.

 Another variable that the fixture addresses is the different splay of the legs. You can see this in the photo below if you look closely.

The slot on the leg in the foreground is slightly tilted off the axis of the leg. You can especially notice this if you compare the half circle shaped material remaining at the bottom of the leg. The slot in the leg in the background does the same thing, but in the opposite direction. The reason for this is that the slots must be oriented to split the difference between the splay of the front and rear legs.
Most importantly, the slot is in the center of each leg at the deepest point, for strength. The jig does this automatically. I'll explain how it does this later, but for now, I just want to point out the variables.

The process follows these steps.
First, I measure the splay of the front and rear legs, in this case 13 degrees for the front and 19 for the rear, which gives me an average of 16 degrees. I pivot the central panel to 16 degrees, push the chair up against the jig and position the two platforms. Then I route the slots.
Next, I swing the pivoting panel the opposite direction (16 degrees again), with the platforms still fixed, reposition the chair, and route the other legs.
Using the fixture was a breeze and so many of the troublesome layout and fitting issues that I've always encountered were either eliminated or greatly simplified.

Above, you can see how I measure the slot angles to transfer to my rocker pattern. If all is right, there is no fiddling around or fitting and I can repeat the results on the next chair. I will be shooting video of the process, but I think that introducing the variable over a few posts might make it all more understandable.

Rocker Jig Progress

I found a place to buy 3/4" baltic birch plywood and started working out the design of the rocker fixture. Here are the results so far.

I've eliminated the base that I used in Australia, opting to use the bench and a couple of clamps. It makes the jig much smaller and easier to store. I'll go into more of the details as it comes to fruit.
As you can see, the central panel swings both directions so that the platforms on the top can be set once in the process. If you aren't familiar with original, you might understand it once I shoot the videos.
Here are the platforms that the router runs on. If you click on the images, you can see them larger.

Just a few slots and hardware to make the platforms adjustable and I'll be ready to route. It's almost worth all the splinters... almost.