Both the handrims and fenders use a wooden bender that has been designed to make bends with a large radius. While you won't need the finished handrims until the rear wheels have been built, it is easier to describe how to bend them both at the same time. Directions for bending both the handrims and the fenders are included in this chapter. The fender has been designed to fulfill several functions at once:
1) When folding the chair, the fenders and the seat guide hooks serve to guide the seat bars as they slide up and down.
2) The fender serves as an armrest, and can support a higher armrest if needed.
Conventional fender/armrests need to be removable to allow the rider to slide in and out of the chair sideways. The ATI-Hotchkiss fender/armrests are low enough that they do not need to be removable.
3) On a conventional wheelchair the fender is square. Our curved fender helps to reduce the stresses on other parts of the chair by giving the frame more flexibility.
For most riders, the ATI-Hotchkiss fender performs all the functions of an expensive removable desk arm while significantly reducing the number of parts and brazed joints. Thanks are due to the wheelchair makers in the Philippines and Japan for the concept of a curved fender bar.
MAKING A FENDER FOR A 24" WHEEL
MATERIALS
| ITEM | QUANTITY |
| 3/4" O.D. tubing or 1/2" thin wall conduit | 1 piece, 5 feet (152 cm) long |
| 1/2" x 1/8" (12 mm x 3 mm) steel bar | 2" (5 cm) |
JIGS AND BENDERS USED
Wooden Tubing Bender and Fender Die (11-1/2" (29.2 cm) radius die for a 24" wheel; 12-1/2" (31.8 cm) radius die for a 26" wheel)
Brake Catch and Stop Welding Jig
(The bender and jig are included in the Basic Tool Kit. Instructions for making them can be found in Appendixes A and B.)
DIRECTIONS FOR BENDING A FENDER FOR A 24" WHEEL
It is difficult to bend a perfect fender the first time. The Basic Tool Kit includes a sample fender for a 24" wheel. We have also included diagrams for fenders for both 24" and 26" wheels. These diagrams can be enlarged to full scale drawings. Comparing the fender you are bending to either a sample fender or full scale diagram will help you to make a fender that fits.
1) Cut two pieces of tubing 30" (76cm) long. Measure and mark the tubing as shown. Mark all the way around the tubing.
2) Bolt the 11-1/2" (29cm) bending die to the wooden fender bender. The wooden bender should either be bolted to a workbench, held in a vise, or attached to a wall near a corner.
3) Line up one of the marks on the tubing with the bottom edge of the bending die. Loosen the nuts on the bending chock and move the chock until it presses against the tubing. Then tighten the nuts to hold it in place.
4) Bend the tubing around the die until the other mark touches the die. Use a cheater pipe (a piece of pipe that fits snugly enough over the fender tube) to help make the bend. The tubing will spring back slightly.
| 5) Check your bend against the sample fender from the Basic Tool Kit. If you don't have a sample, draw a full scale diagram from the diagram found at the end of this chapter and use it to check the accuracy of your bend. 6) Turn the fender over, and line up one mark with the top of the bending chock. Only 7" (18 cm) of tubing should extend above the top of the bending chock. Slip your cheater pipe 1-1/2" (38 mm) over the end of the tube. Sight along the bender to make sure that the first bend is in the same plane. Bend the end of the tube until the cheater pipe touches the end of the die. Again, the tubing will spring back slightly. Check the bend against a sample fender. A finished fender should lay flat on the floor or table. |  |
