Every year, the Rural Studio, a program of Auburn University's architecture school, located in Hale County, Alabama, pursues a research project called the 20K House. We build a house on a budget of $20,000 that can be a sustainable, safe, spacious, dignified replacement for the mobile home. Each prototype is then documented and will hopefully become a model that can be replicated across the rural south for low-income homeowners. 20K 9.0 can be seen in pictures here: http://www.flickr.com/photos/20khouse. Learn more about the work of the Studio in general at http://www.ruralstudio.org.
A key feature of our house this year was the front porch -- an important feature in southern homes in general -- and I wanted to round it out with a rocking chair for our client, MacArthur Coach. To make it part and parcel of the house itself, the materials were salvaged from the construction process, and the dimensions were customized to Mac. Much as the house itself is a modern take on the traditional southern vernacular, this chair is a contemporary rendition of the classic southern piece of furniture, the rocking chair.
The two "A" frames that comprise the rockers and arms are made from the pallet wood that the roof metal arrived on, which turned out to be nice hardwood -- I think it's poplar, but I'm not sure. Pallets are often made from hardwood because of the weight they must bear. The seat itself was made from leftover 2" x4"s, and the seating surface was made from the cardboard tubes that come at the center of the rolls of paper that we plot our drawings on. This way, the chair materially referenced both the house itself and the process by which it came to be. I have done another project with these tubes, which are very strong, and it can be seen here: https://www.instructables.com/id/Paper-or-Plastic-Table/.
While the design is fairly simple, you'll need some serious tools to make this chair. It took about twenty hours to build in my spare time with everything at hand. Given that the wood and tubes were salvaged, I only had to buy fasteners and finishes, which kept the price to about twenty bucks.
Check out this nice blog post from the good folks over at ReadyMade magazine: http://www.readymade.com/blog/design/2010/10/07/rock_this_way
You will need these tools:
Compound miter saw/ chop saw
Assorted drill bits
Sandpaper -- 100 and 220 grits
You will need these materials:
Several 3'-4' by 2" square pieces of pallet wood (approximate)
12' running feet of 2" x 4", in pieces no shorter than 2'
12-24 cardboard tubes, minimum wall thickness of 1/8"
4 1/2" dia. by 3' long threaded rods
12 1/2" nuts
12 1/2" lock washers
6 #10 by 2" machine bolts with associated nuts and washers
Much thanks to my teammates, Clem Blakemore and Pernilla Hagbert, and our teachers, Andrew Freear and Danny Wicke, as well as the whole faculty and staff of the Rural Studio, and our fellow students. Also thanks to Auburn University and Regions Bank, who funded this prototype.
Step 1: Millin'
When using scrap wood, the first step is always to cut it down to something straight, even, smooth, and usable. Break apart the pallet, taking special care to remove all screws, nails, staples, or anything else that could cause trouble when cutting. Using a table saw, take a blade's width off each side of the wood, more if necessary to remove bark or damaged portions along the edges and corners.
I ended up with four pieces or so, two that were 1-1/4" by about 2-1/2", and two that were 1-1/4" square. These will make the side "A" frames.
For the sides of the chair piece itself, the "L", take four pieces of 2" x 4" that are about 2' long, raise the blade of the table saw, and cut them lengthwise, splitting them into two pieces each that are approximately 3/4" thick by 3-1/2" wide by 2' long. You may want to trim down that width, depending on the diameter of the cardboard tubes you end up with; my tubes had an outside diameter of 2-1/4", so I cut down the 2" x 4"s to 3" wide.
All dimensions in this project are suggestions. Adapt them as necessary to the specific wood you have on hand, the size of the person you are trying to accommodate, etc.
Step 2: Notchin'
The joints in this chair are all simple laps. There are many ways to notch wood, and you might choose the one that best suits your tools and situation. You could cut them out with a bandsaw, go old school with a Japanese handsaw, or tackle it with a chisel.
I found the most expedient method was to use a radial arm saw. First, cut your newly milled wood to length according to the drawings on the first page, with one piece for the arm and two for the uprights out of the 1-1/4" square pieces, and one piece for the rocker out of the 1-1/4" by 2-1/4" pieces. Lay them out on the table as shown and scribe the angles for the joints with a pencil. Set the the radial arm saw's angle to match the angles of the joints and set the saw depth to cut halfway through the wood. Pull one cut, slide the wood over the width of the blade, pull another cut, rinse and repeat. Cut all the notches for all the pieces this way. It sounds tedious, but it really doesn't take very long.
Step 3: Rockin'
The rocker is obviously a critical part of the chair, and I'm not sure I got it quite right. It has a lot to do with feel and balance, and, given that it is a dynamic element, it is hard to tell how it will work and sit until the whole chair is in place. In general, from my study of rocking chairs, you want a long taper in the back to prevent the thing from tipping over when you lean back, and a shorter, steeper slope towards the front end of the rocker. You also want to keep enough wood at the ends of each rocker to make a strong joint to the uprights.
Use the drawings at the front page of this Instructable as a reference for laying out your curve, then cut it on the bandsaw and sand it out smooth. Put it on the table and test-rock it for flat spots and smooth motion. Mess around with it until it feels good.
Step 4: Gluin'
Once you've got the rockers where you want them, glue them together with a liberal amount of wood glue on all mating surfaces inside the joints. Clamp heavily and leave be for a couple of hours.
Once dry, cut off the excess bits that hang over with a handsaw flush. Sand smooth. Peel up excess glue squeeze-out with a putty knife or a razor blade.
Step 5: Splicin'
If you want a low-slung chair, or had some foresight, you can ignore this step. I realized after I made the "A" frames that they were a little low for Mac, who is a big man and who also has arthritis, which makes it hard for him to get in and out of chairs. I wanted to raise the seat up some, so I had to splice in some bits of wood to make the "A" frames taller.
The process is simple: using the same lap-notching scheme, cut in some pieces to raise the height of the frames about six inches. To avoid this, just use longer wood in the first place. I kind of like how the patchwork look worked out. This is an advantage of the design-build process, and, as a creator, you have to be able to adapt to realities on the ground.
At this point I also added little machine bolts through each joint. While not strictly necessary, they are just a little extra security for a chair that I know will take a beating over time. Mark the center of each joint first, then put a pilot hole straight through, which locates the center point on the backside. Then use a spade bit to make a countersink for the washers, nuts, and the heads of the bolts. Finally, go back with a bit slightly larger than the machine screw and make your final through-hole.
Step 6: Seatin'
The actual seat part is made of cardboard tubes and the 2" x 4"s you split in the first step. Lay out the pieces to make an "L" that seems comfortable, usually a little more than 90 degrees, then scribe your lines and cut the miters. Each "L" is comprised of two layers; at the joint, the layers overlap one another to make the joint as strong as possible.
I made each leg of the "L" equal, at about 18"; this is a bit deep for a seat, but, as you can see, the tubes don't run that whole length. The actual depth of the seat is only about 16", which is deep and generous enough for a reclining-type chair. I laid out the tubes with some space between them -- otherwise, there will be a deep and somewhat awkward "V" notch between each set of tubes that will collect dirt and crumbs and so on. The gap also will help with sweaty back syndrome by allowing for some airflow.
To seat the tubes, the inner layer of the "L"s are hole-sawed out. The tubes I used have an outside diameter of 2-1/4" inches, so I made the holes just that size for a tight fit.
Once the inner layers have been drilled out, laminate them to the outer layers with a lot of glue, lapping the joint. I also used screws, but again, they are not strictly necessary.
Step 7: Tubin'
Since Mac is a big man, I felt the need to reinforce the tubes, though for most folks, this is probably unnecessary. Simple cut out a slice of a tube, to make a "C", then squeeze it together into a smaller diameter, and force it inside another tube to make a double-walled tube.
Cut the tubes to length -- my chair is 22" wide, which is a lot. It could easily be 18", or even a little less. Make sure you accommodate for the amount of tube buried in the wood on each side -- 3/4" on each side, for a total of 1-1/2" -- so the tubes should be 1-1/2" longer than whatever you want the final width of the seat to be.
Seat the tubes in one "L" with some glue, then in the other side (it can be tricky to line everything up), and then clamp the hell out of it.
Step 8: Assemblin'
Putting this thing together is the last major, and trickiest, step. First, sand everything thoroughly with a power sander until all the pieces are flush. I heavily rounded the edges, but that is a matter of taste.
To get a sense of the balance of the rockers and how high the seat was off the ground, etc., I clamped it together first. Once I was satisfied with how and where it sat, I scribed the position on one "A" frame, then un-clamped, and transferred those marks to the other side. It's important to do it this way, instead of just scribing both sides, because making each frame identical is the best way to get it to sit evenly. Drill 5/8" holes and countersinks for the nuts and lock washers in the "A" frames. Clamp everything back and mark where the holes hit on the seat frame. Drill 5/8" holes again (to give yourself some wiggle room) in the seat frame. Make sure your holes lie somewhere within the tube so the threaded rods are hidden. Measure and drill holes and countersinks for the rods that brace the rockers at the bottom as well.
The tricky part is getting the rods through and everything aligned. Put some glue on the "A" frames and the chair where they intersect around the holes. Line up one side, put the rod through, dope up the other side with glue, and push it through. Tighten all the nuts down. Trim one side of the rod and tighten it down. You'll need a wrench or ratchet or something on both sides, because the rod will just spin unless you work on it from both sides. Use the rods at the bottom to brace out the "A" frames and twist the wood if they are warped, adjusting them until they are the same width apart as they are at the top. If you use lock washers, no need for thread lock in the nuts.
Step 9: Finishin'
Go over with any hand touch-up sanding to remove glue spots and so on, and use wood fill if and where necessary. I hand-rub the polyurethane with rags, because the brushes are hard to get between the tubes and so on. The cardboard really soaks up finishes well, but tends to dry rough because the moisture in the finishes raises the little fibers in the cardboard. Smooth them out with 220 grit after the first coat has dried, then run another layer of finish. Make sure you get a couple of good coats on the runners.
Sit down and enjoy, you deserve a rest!