Rockers (Part 3)

This weekend I finished shaping and sanding the headrest.  That was the last step in completing the main portion of the chair.  Then I moved on to the rockers. 

The Brock instructions and video get a bit sketchy at this point.  The instructions simply point to the video for a construction step that I feel is critical to the project: the balancing of the chair.  But the video lacks detail.  In fact, much of the video goes on with no narration at all, so it’s assumed that you can follow what he is doing.  I had to watch the video several times to understand the transition locations, and even then some of what I did was a guess.  There is a new version of the video out now, so perhaps more detail has been added.

Brock sets the chair and rockers on a table saw.  I assume this is because the saw provides a smooth and level surface, but the video doesn’t give a reason.  I used my portable bench and adjusted the table to ensure it was level.  The instructions say to balance the rockers at 2.5” forward of the rear legs.  I found that I could not get my chair’s balance point to go that far forward.  The headrest may be too heavy, but I was not willing to take more material off at this point.  Instead, when I made up the rocker-to-leg transition laminations (see below) I used 5 for the back legs and only 3 on the front legs.  This helped to tilt the chair forward, but I still ended up with a balance point just 1.5” in front of the rear legs.

The transition pieces were created using the same process as the rocker laminations.  I jointed a 1.5” board, cut a thin strip on the band saw, and then planed the strip to size.  The strips were then cut in 6” lengths.  The front rocker transition can be mounted starting right at the front of the rocker.  The rear rocker transition begins at the balance point and goes back from there (see photos).  Once these locations were determined, I glued them up and clamped them using the rocker lamination jig. Don’t for get to wax the jig and use wax paper under the laminations.  I let them sit over night to dry.  Finally, I jointed the sides to ensure the transitions were aligned flat with the rocker.

Earlier in the instructions, it says to cut the bottom of the back legs off at 6 degrees.  But 6 degrees in which direction?  Now that the legs are sitting on the transitions, it is clear to see which way the legs need to be cut.  Here’s a picture of a leg before the cut.  I drew a line parallel to the transition to mark where the leg should be cut and then used a dozuki saw for the cut.  The front legs also required some work to make them flush with the transtion blocks.

The last step I did was to drill the dowel holes for the front legs.  I did this using a Dowel-It jig.  Because I decreased the number of laminations on the front, I had to also decrease the drill depth.  I normally use a brad point drill bit, but this might have poked through the bottom of the rocker, so I used a regular 0.5” drill bit instead.  I created dowels using oak stock.  I fluted the dowels to allow the glue to move around it.

My next steps will be to saw the transitions so they flow into the legs, shape the rockers, and then permanently install them.  The end is getting close!