Maloof Rocker – Roughing into SketchUp
Readers who know me will recognize my shift into the contemporary world with this blog entry. I admit being stuck in the 18th C with my furniture interests, but this excursion was far too tempting given the recent passing of woodworking icon Sam Maloof (1916-2009).
My students expressed interest in building a Maloof Rocker and I am taking on the challenge. But first, it is critical for me to understand the design, details and joinery by “constructing” this chair (or any first-time piece) in SketchUp. So this entry will identify my methods of building the computer model of a Maloof Rocker.
Two Fine Woodworking references were important to this task, issues No. 25 and 42.
Step 1: Import (as an image) the orthographic sketches from Sam’s article How I Make a Rocker in Fine Woodworking issue #42 into SketchUp. After import, square the image with the red and blue axes. Also use the Scale Tool to make the dimensions in the image equal to full-size in SketchUp.
Step 2: Begin tracing (with the Line and Arc Tools) over the shapes of the seat, front and back legs. Make individual groups for each separate piece. You can see the resulting flat shapes the picture below. I was careful to build these shapes exactly fitting together at the joints.
I also scanned the front orthographic view from the magazine and traced over the front face of the back leg.
Step 3: I worked on the Seat first, changing the flat group made above into a half-seat component. (For symmetrical pieces, I find it quicker and easier to work on only the left or right half, later copying and flipping to make the whole). Before making the seat a component, I rotated the group so it lines up with the red, green, and blue axes. This makes it easier to create joinery with the component in this non-angled orientation.
I find the joinery in this chair to be interesting, particularly the seat joints. Below I’ve tried to represent the joinery used by Maloof from the information provided in the Fine Woodworking articles. This view of the seat (from the back corner) shows the joint for the back leg. The front-to-back face of this joint is made at a 5 degree angle to provide the back leg splay. (Note that I’ve shown square corners on the top surface of the seat – Maloof used a radius in the corner).
Step 4: Next I developed the front leg component which is turned using the Follow Me Tool. The square section provides the socket to fit into the seat joint. I made this leg centerline to be perpendicular to the seat. There are dowel sockets in the ends of the legs for connecting to the rocker and the arm.
Step 5: The Back Leg requires an extra step using the Intersect feature in SketchUp. The front face shape needs to “intersect” with the side face. Use the Push/Pull Tool to give the Front Shape its thickness, enough to fully pass through the already thicknessed Side Shape. Then explode all the pieces, select all, and execute Intersect with Selected. Use the Eraser to clean up all the waste.
Step 6: Create the dado joint in the bottom of the leg. This must be done on a 5 degree angle to provide the splay.
The remaining parts are created similarly and we have a rough chair as shown below.
The model represents a rough band-sawed shape and clearly lacks the smooth rounded features of a real Maloof design. However, I will probably not attempt smooth shaping of the model, as it would be difficult. Also, I don’t need smoothing information from the model to proceed efficiently with construction in the shop.
UPDATE: I’ve just roughed this out in the shop….. now for the job of fairing, shaping, rounding, etc.
A number of full-size templates fall out of the 3D model. For the long ones, I paste to 1/4-in. plywood. Otherwise, they are backed with regular poster board. Here is a picture of the complement of templates used.