The prototype wheels are very complex castings and would be very time consuming, so my wheels for this truck needed to be a little more simple.
The RimFor these wheels, the main tool I use is a two-inch outside-diameter piece of Plastruct round tubing (TB-200). I will use this as a form for the two .030 strips of styrene as I use hot water to shape it, and hold the shape when gluing.
1- Out of .030 sheet styrene, cut two 7/8 inch wide strips for the rear wheels and two 3/4 inch wide strips for the front wheel. One long enough to go around the tube and one long enough to go around the tube and the first strip. Cut these strips longer than the needed length, these well be cut to the correct size after the strip has been formed.
2- Pull the strips though your thumb and finger to start the curve, and place both strips around the tube and hold in place with rubber bands. Place in a glass bowl and cover with hot water and let set tell water has cooled. Remove from tube and cut to length. Now place the two strips back on the tube and glue together staggering the joint 180 degrees apart, being careful not to glue it to the tube. I use a liquid plastic cement.
The Center Disk1- Cut a two-inch diameter disk out of .030 styrene. I use a good quality compass with a metal tips on both points. Drill a small hole in the center to help hold the tip in place. You need to go round and round many times from both sides, break it out when you get a good score and sand the disk to size.
2- I start by drawing a six-inch circle with a two-inch circle inside that circle on a piece of paper. I use a protractor to mark the segments on the six inch circle. The front wheels are divided into ten spaces and the rear wheels are divided into nine spaces. Draw the lines from center to the outside of the six-inch circle.
3- Place the styrene disk on the drawing and add the lines for the spokes. draw a one inch circle to both sides of the disk.
4- Add three layers to the out side of the disk.
a. Add a one-inch outside-diameter exchanger ring from Plastruct (RI-32) with .188 x .100 x 1/2 long strips of styrene (cut out the spaces between the spokes on the disk.)
b. On top of the exchanger ring add a one-inch diameter button.
c. And on top of that I used some cone shape parts out of my junk box.
5- On the inside of the disk after enlarging the center hole to 1/8 add one or two 1/4 scale Grandt Line circus wagon wheel (#30 or 31), the one that is one-inch diameter. This will give a good solid hole for the axle.
Place this assembly inside the rim and add a thin slice of the two-inch round tubing one on each side of the disk.
The Hard Rubber TiresFor the hard rubber tires cut a slice 3/4 wide for the rear wheel, and two 5/16 wide for the front wheel out of two-inch ABS pipe. This is inside-diameter and will not fit over the rim, so I cut it in one place and added a short segment to get to the right size.
I have added a photo showing some of the parts.
Gordon Birrell
http://www.flickr.com/photos/77318580@N00/
