Introduction: A Custom Chair Headrest Mount
My main at home office chair (Herman Miller Embody) does not have a head rest and there isn’t one available to be purchased for it. It is likely due to the design of the chair, since it does not have any solid material near the top where one could mount one (see photo). On top of that, the top of the chair flexes backwards as you lean back and in fact the entire back and seating area flexes about making it difficult to attach anything to it. The “spine” at the back of the chair that supports it is curved (like a spine) and also rounded over and hollowed out. This makes it challenging to attach a conventional headrest to it. I had been toying with the idea of making a custom headrest mount for it and finally figured out a way to do it.
Step 1: Design Details
The “spine” of the chair does not allow for any easy way to affix anything to it and I also didn’t want to modify it just in case it would become structurally weaker. I decided to make a removable “clamp-on” head rest mount. I had some initial sketches and then eventually made some 3D models. The drawings give dimensions in both inches and millimeters; I have no issues with converting between them while I work.
The bent arm/spine may look as if it were more curved than necessary, but the clamp will be further down the chair “spine”. This allows the arm to curve around the back of the chair with sufficient clearance to reach the head area. The actual length and curvature was estimated after the clamp was built and a straight piece could be positioned In the clamp.
Step 2: Parts Needed
The mount was built from some scrap wood pieces and jig fixture components:
- Some hardwood for the clamp and the top mounting block
- Some hardwood that can be re-sawn for bent lamination (approx. 3” x 24” x 1”)
- A pair of wing knobs (female thread) and some matching threaded rod (I used ¼-20 based parts)
- 4 T-Nuts with the same thread as the threaded rod (1/4-20 for me)
- A headrest suitable for mounting such as a Lorell LLR 85562
- Wood glue, 5 minute epoxy & some screws (1 ¼” #8)
- Spray paint (I used matte black)
- Some foam-like material for padding the clamp (I used drawer liner)
If you make this or something like this for yourself, you should decide what finish you would like on it before you choose the materials (e.g. type of wood). My initial choice was maple for everything, because I had scraps of it and maple is quite strong. However, for the “bent arm” I only had some mahogany that was salvaged from an old futon sofa I disassembled. While mahogany is strong enough, it has a more open grain and that shows more when spray painted.
Step 3: Construction of Chair Clamp
The clamp was built first. This was not only so I could test how well it would hold, but also get an estimate of how long the arm/spine to hold the headrest itself would be. Initially I was going to cut a large dowel in half for the part that goes into the hollow of the chair spine, but then decided to simply cut out two parts from some scrap maple I had available. I profiled the shape by pushing a piece of solid copper wire into the hollow and then tracing that onto the wood. They were sawn out and just glued onto the piece that formed the inner clamp part. The finish didn't matter too much, as it would be painted and have some cushioning foam attached to it later. Prior to that I drilled clearance holes for the ¼”-20 threaded rod as marked in the drawing.
The wing knob bolts were made by cutting two 4” (roughly 100 mm) pieces ¼”-20 threaded rod and gluing them into the wing knobs with epoxy. The t-nuts were initially installed with a light tap for testing and then later recessed and put in place with a bit of epoxy as well. After painting a piece of foam drawer liner was stuck over the two humps with some two-sided tape.
Step 4: Bent Arm/Spine Construction
The bent arm was made by re-sawing some ¾” thick lumber (left over from disassembling my old futon sofa) into 1/8” thick strips and gluing them together in an arc shaped form. The pieces were a bit wider than the slot in the clamp, since they would be trimmed to size later. The amount of curvature was estimated by first fixing the straight board to the clamp and then measuring the distance to the back of the head of a volunteer (while holding the Lorell headrest roughly in position). As the headrest itself as well as the clamp position was adjustable, these measurements did not have to be very exact.
The piece was oversized to begin with (over 25” long), so I did a test assembly with arm held in place with clamps while checking the range of movement and height. The arm was then cut to length and the section that would make contact with the clamp was hand planed slightly to flatten it out for better surface contact area.
Step 5: Construction of Top Mounting Block
The top mount was made from a small piece of maple that was cut square initially and then (after all test fits were done) shaped to mimic the outline of the Lorell headrest mount. I simply laid the headed rest mounting end over a piece of maple and traced it generously (including the mounting holes). Everything was cut to size and another test assembly was done before the final glue-up. The top side of the arm/spine had to be hand planed a bit as well to flatten it prior to gluing.
Step 6: Final Assembly and Finishing
Finally, all parts for the arm/spine were glued and screwed together and then installed on the chair to test it with the Lorell headrest attached. The two cap screws for mounting the headrest that were included were not long enough. I instead used two 1/4"-20 cap screws with 1-1/2" long threads.
After verifying it would work, parts were sanded and spray painted in a make-shift spray booth (cardboard box) outside under my deck. They were given about 8 coats with some light sanding in between the first few to knock down the raised wood fibers.
Step 7: End Note
I've been using the headrest for a couple of weeks now and it works great. I wish I had thought of this idea sooner, as I've had this chair for 8 years now. The matte black finish and curved mount support really suits the style of the chair in my opinion. In hind sight I should have used maple for the bent arm/spine. It has a less open grain and it would have been easier to get smooth finish for spray painting.
Second Prize in the
Modify It Speed Challenge