The Joel Hollingsworth Bellows

Editor's note: An UC Berkeley e-mailed project suggests how to add another functionality to your stuff sack.

Consider a bellows by Joel Hollingsworth

You could make a kick-ass bellows out of that stuff sack, if you made a new one out of seam-sealed silnylon with a few modifications.

Remember the shape of the little sour cream cartons that come with Wendy's baked potatoes? That's your bellows, since the stuff sack is already a tube sealed flat at one end. You just need to attach (aquarium cement would probably work) the "lock" from a ziplock bag (or a tortilla bag if you're as cheap as me) at the other end so that it seals at a right angle.

Attach this below the drawstring, and attach your hose a bit below that.

Four bamboo skewers, cut to the proper length, will follow the "folded edges" of the sour cream carton, and by grabbing the corners of your bottom seam and pushing them apart and together, you can work the bellows.

Now just add a flapper valve at one wall (look at a regular bellows for notes on this device), and a one-way valve to the hose, and you're in business!

A little more weight, but no annoying blowing. Note: Use duct tape wrapped around the skewers to join them into a square with a little slack (1/16") at the corners. Then they won't pierce the stuff sack. Also, you may want to run some elastic from one corner of the ziplock, up over the center of the bottom seam, and back to the other corner so the fabric doesn't baloon out when you squeeze. It's a lot simpler than it sounds. I attach some cheesy Paintbrush drawings of the bellows, and further reflection has suggested some design improvements. First, seam sealing is probably extra weight. Second, I've realized that it needs something to hold the skewers in place, so I've designed accordingly. Here's a key for the drawings: Top, far left: My inspiration, the Wendy's sour cream carton. Top, left of center: skewer taping diagram. Top, right of center: Use #1: A Stuff Sack. Top, far right: Use #2: A Bellows. Bottom: Cutting & Seam Pattern More Instructions: You need: a piece of silnylon four times as big as you would need to cover your disassembled stove, plus seam allowences on all sides; thread; a drawstring; a ziplock bag; bamboo skewers; duct tape; aquarium cement; a check valve; aquarium tubing of the same size; a couple inches of copper tubing. Fold the fabric in half so that the short sides meet, and lay it out with the fold on the near side. In the pattern, the black is the bottom layer, and the blue is the top layer. Solid lines of these colors are cut edges. The black dashed lines are seams, the gray curve is where the drawstring will go, and the yellow lines are the fold lines for "stuff sack mode." You should mentally unfold this pattern, and physically unfold the cloth. It's not to scale; obviously, the diagonal dashed lines should all be the same length, but it was funner to shade than to fix that detail. Here's a guess at how to sew the thing up, after you've cut an isosceles and two right triangles of of it, cut the flap and cut out the holes. First, sew the zigzag seam (use straight stitches! but sew the diagonal lines.) Now, fold the piece in half again, so that what are now the short sides meet, and the diagonal cut edges are facing out. Sew the seam that appears on the sides of the pattern, leaving a space near the bottom where you'll glue in the check valve and tubing. Next, open the piece out into a tube, and flatten it again so that it's folded along the yellow lines. The seam you just sewed should lie in the middle of your piece, and sewing the back seam will create a "T" shape. Now, turn the sack right side out and start working with skewers. Four skewers need to be cut to fit along the diagonals, inside the triangular pockets in the material. Leave the blunt ends on. Lay the ends of two skewers on a narrow strip of duct tape as shown, using scraps as spacers to ensure that the ends are two skewer diameters away from each other, then roll the duct tape around the skewers. Repeat twice, so all the skewer pieces are in a line. Fold the ends of this line in to the center, and thread this into one of the small holes for the drawstring, and work it around until it follows the diagonal seams. Poke the two free ends of the skewer out of the drawstring holes, and join them like all of the other ends. Now sew the final seam, sealing in the skewers. Thread the drawstring through, and you''ve got a working struff sack. Open the drawstring fully and open the sack such that it looks like that sour cream carton. Let the back corners collapse together. Find a ziplock-type closure of the right length, and glue it on so that itdoesn't interfere with the drawstring, being careful not to let it leak at the corners (You might want to leave an inch or more of bag on, gluing only the edges, but make sure that the ends of the skewers will butt up to the inside of the closure while you're using the bellows). Trace the diameter of your check valve onto the side opposite the air intake. Cut an x or * shape or something with even more points inside this circle, staying a little bit inside the line. Slide the valve out through this opening and glue it in place. Glue a thin strip of fabric around the valve, covering all of the points of fabric. Attatch aquarium hose to the valve (if this is done removably, the hose can fit seperately into the bag, otherwise it'll thread into the opening, leaving a little loop, as shown) and a short piece of copper tubing to the hose, and you're finished. Enjoy! Joel Hollingsworth UC Berkeley

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