Mark (TheCraftsmansPath.com) on December 11th, 2009

The arms for the chair start with two rectangular blanks about 5 inches wide.  These blanks needed to be roughly shaped before the outlines of the actual arms can be cut out at the band saw.

Marking Arm BlanksThe shaping process for the arms involves two steps.  The first step utilizes a jig that facilitates cove-cutting a grove diagonally along the length of each arm blank.  This cove cut removes stock that will eventually become the area that your arms rest in when sitting in the chair.  The second step of shaping the arms will occur when they have been attached to the chair and more stock can be removed and the curves can be faired into the legs.  Before doing any cutting, I first marked the outlines of the arms on the blanks so that I could see their eventual orientation and not get confused while performing the following steps.

Cove Cutting Arms on Table Saw 1Cove Cutting Arms on Table Saw 2Cove Cutting Arms on Table Saw 3The jig for the cove-cutting at the table saw is a rectangular box with an angled portion that rides against a fence while transporting the arm blank over the table saw blade.  The angled piece allows the blank to travel, top face down, across the blade so that the resulting cove is cut diagonally through the length of the arm blank.  These cuts were done in a slow and methodical manner, raising the blade about 1/32″ – 1/16″ for each pass over the blade.  The jig was moved across the blade slowly to allow the blade to cut the cove as smoothly as possible and to also allow the significant dust to be cleared.  Even with this technique I stopped every few passes and used the shop-vac to clean the dust remaining on the table top.  The jig has handles with threaded rod through t-nuts to clamp the blanks in place as well as a handle to help push it through the blade.  I also used a Gr-ripper push block for added control and security.  The jig flips over and the handle reverses for the alternate arm to be cut with a reverse orientation of the diagonal cove.  The first two pictures show the right arm being cut and the last picture shows the left arm.

Marking Arm Outlines on Cove Cut ARmsBand Sawing AmsRough CUt ArmsGluing Rocker StacksOnce the cove cuts were completed I again traced the outlines of the arms onto the blanks (albeit a carefully due to the now undulating surface of the arms).  Then the arms were band sawed to shape and sanded with the oscillating spindle sander to remove the band saw marks along their edges.  In the picture you can see the rough shaped arms after cutting and sanding.

The other step that I completed at this time was to glue up stacks to the rockers.  These stacks consist of rocker strips and are located at the points where the front and rear legs will contact the rockers.  The stacks serve to elevate the chair above the rockers an additional distance as well as to provide material for shaping and fairing curves from the rockers into the legs.  This was a bit of a tricky operation as the stacks wanted to squirm away while they were being glued.  I again used the same rocker clamping caul to distribute the clamping pressure to the stacks.

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3 Responses to “Sculpted Rocking Chair: Rough Shaping the Arms”

  1. Mark,

    I have seen this type of setup for coves before, however, it is one technique that I have always been a little scared of doing. The rocker is coming along nicely…keep up the great work.

    Chuck

  2. Chuck,

    Thanks.

    The cove-cutting was definitely not something I took lightly. A few things I did made it much safer (these might be of interest to other reading this):

    0) Think and rehearse without the power on before you do anything!
    1) Only advance the blade height by 1/32″ and never more than 1/16″
    2) Only cut going right to left. Move the piece back over the blade before advancing the blade.
    3) Never put your hands directly on the wood. Use push blocks and/or handles on the jig to keep complete control of the piece
    4) Go slow – and take the time to clear the dust away so that the work surface is not overly covered!

    You can see that the jig secures the board with threaded rod and also has a built in handle. I also used the push block for added security. The setup is also benefited because the fence is perpendicular to the blade and not set at an angle. So, all of the force is directly into the fence.

    –Mark

  3. Kudos to you I built custom subwoofer enclosures for awhile and just did not have the patience for perfection

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