Ajustable Observing Chair

. Cut your lumber to the lengths as per plans

- 3 (1 x 2 x 36") - main uprights
- 18 ( 2 x 2 x 1") - fillers between uprights
- 2 (1 x 2 x 18") - leg sides
- 1 (1 x 2 x 16") - leg base
- 2 (1 x 2 x 14") - seat sides
- 2 (1 x 2 x 11 1/16) - seat crosspieces
Note: If you are using lumber thinner than 1" you will have to alter your dimensions to suit.
You may add filler blocks to widen the uprights.

. Drill 3/8 holes in the filler blocks and the main uprights, and counterbore a 7/8" hole, ½" deep to fit the washers & nuts in the top and bottom of the 2 uprights, and at the top of the leg side pieces. Cut 2 pieces of threaded rod 1/8" shorter than the width of the assembled upright. Cut one piece of threaded rod to fit thru the legs and uprights with a washer as a spacer between them.

. Spread glue on all mating faces of the uprights and spacers. Assemble and use the threaded rod to clamp the unit together. Check that all pieces are aligned and square before final tightening.

. After the glue has dried measure the distance to the outside of the legs with the spacer washers between the legs and uprights. Mark the leg base accordingly. Round over the top of the legs before assembling. Drill pilot holes for the #10 x 2" screws and glue and assemble the leg.If you have the tools, dowel the leg base first.

. Measure the outside distance of the upright assemble and add 1/16" to 1/8" to the measurement between the seat sides. This allows the seat to slide up and down without binding; too much will let the seat get cocked sideways and may drop. Cut the crosspieces to suit and then cut the bevel on one side. Drill the holes and counterbores for the back crosspiece, then attach the seat base and back crosspiece using glue and the bolts and screws. After the glue has dried apply the cork (or rubber) to the bevel of the two crosspieces. The cork provides the friction to keep the seat from slipping when you sit on it.

Trial assemble the legs to the main upright and set the length of the cable to get the proper 30° angle of the upright. Place the seat on the upright so that it rests on the legs, then set the bottom crosspiece in place so that the seat is level and mark both sides. Remove the seat and clamp the crosspiece in position and drill and counterbore the holes for the bolts. Assemble with glue and the bolts but check alignment on the upright before tightening the bolts.

. If you have a router then use a ¼" rounding bit to radius all edges or use a block plane. Next, sand all surfaces smooth and clean off all dust, and apply several coats of exterior varnish. Allow to dry throughly and sand between coats. (Don't coat the cork.) After the last coat has dried, install the eyehooks, cable and seat covering. Place the foam on the ¼" ply, then stretch the fabric over it and staple to the bottom. Place this over the seat board and using the ¾" woodscrews, attach from the bottom. Insert an eyehook under the seat board at the front and use a bungee cord to connect to the eyehook at the bottom of the upright. This puts a little tension to the seat and prevents it from slipping when you get up. And that's all!

. You can alter the dimensions to suit your application and available materials. I have seen several made of metal tubing. The commercial version is excellent but is rather very pricey.

Sincere thanks to James P. Crombie for supplying the design, picture and instructions for the chair. You are invited to visit Jim's very interesting Web Page.

Edit: Rachel Cyr