Cork Board Project

I made it at the TechShop (www.techshop.ws) in Menlo Park.

The final project (main image shows a prototype) requires a large number of wine-bottle corks to be cut transversely into two nearly equal lengths. To avoid cutting them individually, this stage involves building a jig to allow 50 corks to be cut in one operation.

The corks are about 1 7/8” long by 7/8” in diameter, or just under that. The sizes vary slightly. This jig will need to accommodate them snugly. (The dimensions given are those used in this project – different ones may be used if convenient, but they will need to be calculated to fit the corks.)

How the corks are used in this project will be described separately. But this section will provide for any project which needs cork segments.

Materials needed:

1. Plywood sheet ¼” thick, 1’ wide by 2’ long.
2. Wooden board ¾” thick, 8” wide by 2’ long.
3. Wooden lath for spacer 3/8” thick, 1½” wide by 8” long.
4. Wood glue.
5. Four wood screws 2” long.
6. Two ¼” steel bolts, 3” long, with wing-nuts, and 4 appropriate washers.

Tools used:

1. Table saw.
2. Drill press.
3. Band saw.
4. Clamps.
5. Belt sander.
6. Hand-held electric drill with sander attachment.

Step 1:

Take ¾” wooden board and mark-up for cutting in two equal pieces, each at least 3¾” wide by 22” long.

Mark-up one of the halves for drilling cork-holes. Omit one hole at the end to ensure orientation. There should be three rows of holes (17, 17, and 16), the centers separated by 1” laterally and lengthwise. 

Step 2:

Cut board lengthwise with table-saw to make the equal halves.

Clamp two boards together and drill all holes 7/8” diameter through both boards.

Step 3:

Take the ¼” plywood and mark up for the backing and alignment pieces. These can be a little over-sized as they will be trimmed later.

1. Backing pieces: 4” x 23”
2. Alignment piece:2½” x 23”

Spacers: make two, each of 3/8” x 1½” x 4”.

Cut plywood into the marked pieces.

Step 4:

Glue spacers in place, one to each board, at opposite ends. (Ensure that the cork-holes are correctly oriented.) Clamp together. Wait for glue to set.

Step 5:

Clean up cork holes using a sander (on a hand-held electric drill.)

Glue backing pieces on the main boards. Clamp together. Wait for glue to set.

Assemble, clamp, and screw two sides together temporarily. Adjust the wood spacer’s thickness if necessary to allow corks to fit snugly but not too tightly. Use several corks for alignment. (Screws are better than clamps for this.)

Step 6:

Trim edges of plywood with the sander.

Step 7:

Plane edge where alignment piece is to go.

Glue alignment piece in place. Clamp, and wait for glue to set.

Trim edges of plywood alignment piece with the belt sander.

Drill a ¼” hole at each end for a ¼” bolt plus wing-nut. This will hold the two sides together when in operation.

Run table-saw precisely along the middle of the alignment piece. (This lets the two pieces be separated and then reassembled around the band saw.)

Disassemble, and drill ¼” holes in the backing plywood pieces, centered on each of the cork holes. (These holes are to allow for pushing out corks that are in tight.)

Step 8:

Test with corks as follows.

1. 1. Put corks in all the holes in the section without the countersink.
   2. Assemble the two sections around the band saw, with the blade right at the end away from the corks. Press the sections together so the corks are in both. (The countersink makes this easier.) Insert the bolts and tighten gently. The alignment piece will position it correctly.
   3. Clamp a piece of wood on the table parallel to the saw blade, and snug against the assembled jig, so that as the jig moves the blade stays centered.
   Measure its position so that it can be repeated even if the alignment piece gets worn.
   4. Start the saw and move the jig through its range, cutting all the corks.
   5. Stop the saw, remove the bolts, disassemble the jig, and inspect the corks

Step 9:

We are done.