Problem: The small nozzles which came with a foot-powered bellows pump did not fit the large inlet holes of my air mattresses. The largest nozzle was about 0.5" diameter (12mm). The inlet in my air mattresses is 1.25" (31mm).

Solution: I fabricated an adapter from junk parts (a plastic funnel, bicycle inner tube, and some copper wire). Adapter works great. It stays well inserted while foot-pumping. Inflates mattresses fast. Project consumed 45 minutes.

Parts and Procedure: See subsequent pages.

Side comments:
- My original plan was to slide the inner tube over the large end of the funnel. Too difficult with the size tube on hand. So I routed it inside as shown.
- Even then, sliding the tube over the small end of the funnel was difficult. Dipping in water helped. Next time, I would use a larger tube.
- Shrink-wrap tubing over the copper wire ends would be nice. Remember to slide it on the hose beforehand. (I forgot, as usual.)

Enjoy easy pumping with 'yer foot.

Step 1: Parts

Find the following parts in your scrap heap:
- A section of long-neck plastic funnel. Mine was intended for changing auto motor oil.
- A bicycle inner tube. Use a section without patches.
- Some small solid copper wire. I used insulated telephone wire, about 24awg.

Optional:
- Large diameter shrink wrap tubing. (I did not think of this soon enough.)

Step 2: Procedure 1 - Funnel Section

1) Insert the funnel snugly into your air mattress inlet hole. Mark the funnel where it contacts the mattress inlet hole. Remove the funnel.
2) Cut out a section of funnel about 1" (25cm) on either side of the mark. Wear safety glasses.
3) Carefully remove any fuzz and deburr sharp edges. Use utility knife, file, or sandpaper.
4) Optionally, cut a short narrow groove near the large end of funnel section. This will help retain the copper wire used in a later step.

Step 3: Procedure 2 - Inner Tube and Final Assembly

1) Choose a bicycle inner tube. Its diameter should be large enough to stretch over the funnel section, yet small enough to fit snugly over the end of the bellows pump's original air hose.
2) Cut a section of the inner tube. Avoid patches. Its length should be about 4 times the length of the funnel section.
3) Insert the tube into the funnel section.
4) Stretch the tube over the funnel section, starting from the small end. Lubricate with water as needed.
5) Secure the inner tube to the funnel section. Twist two turns of copper wire over the tube and funnel. Optional: ensure the wire drops into the narrow slot in the funnel section.
6) Stretch the other end of the inner tube over the bellows pump air hose.
7) Secure the inner tube to the original air hose. Twist two turns of copper wire over the tube and hose.
8) Optional: Cover the copper wire with black shrink wrap tubing or electrical tape if desired.

Step 4: Finished

The adapter is complete.

To use it, insert the end into your air mattress inlet hole. The rubber covering over the funnel will form an air-tight seal. Its tapered shape provides a friction fit to keep the piece in place while you pump the bellows with your foot.

Enjoy!