How to Make (Torch Braze) a Simple Wire Wheel

This Instructable will show you how to create a simple wire wheel for your toy or robot project using inexpensive RG45 Gas Welding Rod and other resources.

Step 1: Gather Materials

Main Item: Wire

Specifically, 3/32" RG45 Gas Welding Wire for the Cart wheels and 1/16" RG45 for the Cart wheel spokes.

For bending, forming, and cutting the wire, you’ll need the following items (at least):

Needle-nose pliers (Heavy Duty)
Wire cutters (Heavy Duty)
Light leather-palmed gloves (to prevent nicks and cuts)
Safety glasses
PVC pipe (3” length or more Schedule 40)
Powered (electric, battery, or hand) Drill
3/32” drill bit

For torch brazing the metal pieces together, you’ll need the following items (at least):

Oxygen/Fuel Torch Set (I use Smith’s Little Torch)
Portable Oxygen Tanks (roughly 8-10 Oxygen tanks per 1 MAP tank)
Portable MAP Fuel Tanks (these last a long time)
Torch Brazing surface (Fire-brick, welding table, or metal sheet)
Bronze welding rod (flux covered)
Welding magnets
Leather gloves (to prevent burns)

Step 2: Form the Wheel Jig

Drill a hole (in the middle of one side) into a 3” or longer Schedule 40 PVC pipe or fitting, using a drill and a 3/32” bit.

Step 3: Form the Wheel Loops

1.Grab the PVC pipe or fitting you drilled in Step 2 with a pair of locking pliers (or vice grips).

2. Push the end of a stick of 3/32” RG45 gas welding rod completely into the hole in the PVC.

3. Bend the wire 90 degrees over the PVC.

4. Begin rotating the wire around the PVC.

5. Continue rotating the wire around the PVC, while keeping constant pressure with your gloved hand on the growing bundle.

6. Release the tension on the bundle after you’ve finished rotating the wire around the PVC. Once the tension has been relieved, cut the wire bundle from the PVC. DO NOT PULL the stub piece of wire from the hole; cut it off.

7. Cut the individual wheel loops from the bundle.

8. You should really get three good wheels from the bundle; two for this project and a spare.

Step 4: Mount a Wheel for Torch Brazing

Shown here is the helping hands device (See my Instructable to convert the Helping Hands tool base to a magnetic base) holding the wheel loop before brazing. This device works great for securing the thin RG45 parts for brazing.

1. Adjust the wheel loop before mounting in the Helping-Hands device, to ensure the wires line up at the gap. If the gap is not lined up, it will braze together crooked, and then you will have a hard time later trying to balance your wobbly wheels on your project.

If your wheels go on a clown car,bike, etc, then this not a problem. Wobbly wheels are funny.

Step 5: Light Your Torch

Prepare Your Torch for Lighting per the Manufacturer’s Instructions First!

Open the torch’s fuel (MAP) valve slightly and light the torch.
Using the MAP fuel valve on the torch, adjust the yellow flame to about 3 to 4 inches in length.
Now, carefully crack open the torch’s oxygen valve.
- + If the flame goes out, quickly close the oxygen valve, and then quickly shut off the MAP gas.
- + Then ventilate the area to clear the gases :) away from your site; then start over at (Go to 1).
Slowly increase the flow of oxygen. The flame will turn from feathery yellow to a blue light-saber, with a blue-white cone in the middle.
Increase the oxygen a little more (slowly), and both the outer blue aura and the inner blue-white cone will shrink even more, with the cone about ¼” to ½ inch long.

At this point in the process, the blue flame will sound like a very light wind or hiss. This means the flame is optimal for heating the wire to dull red and also perfect for melting the bronze rod to join the wire.

Step 6: Torch Braze a Wheel (to Close the Gap)

After your torch is lit and ready, direct the flame on the gap.

Once both sides of the gap turn red (1/16”to 1/8” on both sides), place the end of the bronze rod on the gap.

Heat the bronze rod and the metal surrounding the gap (1/16” to 1/8” on both sides) until the bronze rod melts and flows.

At this point, remove the bronze rod but continue heating the gap until the bronze flows and fills the gap and coats the surrounding metal (1/16” to 1/8” on both sides).

When finished brazing, pick up the wheel loop with pliers or leather gloves and quench it in a container or stream of cold water.

Step 7: Form a Wheel Spoke

1. Position a 4” piece of 1/16” RG45 with the needle-nosed pliers (in center)

2. Bend the wire around the needle-nosed pliers as shown.

2a. Bend the wire around the needle-nose pliers for two loops total.

3. Flatten the loops together with the needle-nosed pliers.

4. Adjust the spoke to ensure it is straight vertically. Notice in the picture, the lopsided design of the spoke. This observation will come in handy when brazing the spoke to the wheel.

5. Adjust the spoke to ensure it is straight horizontally.

Step 8: Prepare a Wheel and Spoke for Brazing

Draw a cross-hair target on a sheet of paper using a compass and ruler.
1. Center the wheel loop using the cross hairs.

2. Place the spoke on top of the wheel loop.

3. Once the spoke and wheel loop are in their optimal positions, mark the intersecting points on both the wheel loop and the spoke (with a marker).

Notice in the second pic, one end of the spoke is shown on top of the wheel loop. It may be easier to lay both ends of the spoke on top of the wheel loop for marking purposes, but remember before brazing them together, one end of the spoke fits underneath the wheel loop and the other end of the spoke lies on top.

Step 9: Braze the Spoke to the Wheel

Using welder’s magnets, or other means, to hold the pieces, arrange the spoke and the wheel loop for torch brazing as shown in the picture.
Based on the purposely lopsided design of the spoke, arrange one side of the spoke underneath the wheel loop and the other side of the spoke on top of the wheel loop. This will align the axle loop inside the wheel loop.
After arranging the pieces, torch-braze the left side of the spoke to the topside of the wheel loop. Without flipping the hot piece over, braze the right side of the spoke to the underside of the wheel loop.
Pick up the hot piece with pliers or leather gloves and dowse in a container or stream of cold water.
After cooling the wheel, adjust the spoke as required with needle-nosed pliers to center the axle loop.

Step 10: Cut the Excess Wire From the Wheel

Using wire cutters, cut the excess wire from the outside of the wheel.

Step 11: Grind the Rough Edges From the Wheel

Using a grinder or grind wheel attachment on a rotary tool, grind the rough edges from the wheel as needed. Please don't be too aggressive with the grinder. For example, if you grind away too much of the bronze rod, you won't have anything keeping the joint together. If this happens, the joint will have to be re-torch-brazed.

Step 12: Repeat Preceding Steps for a Second Wheel

Repeat all the preceding steps, and you should have yourself two complete wheels for your project.

Congratulations!

Step 13: Test Fit Your Wheels

Test fit your wheels on your project. Shown in the picture are the wheels temporarily mounted on one of my push cart toys…Clyde the Caveman.

Step 14: Permanently Mount the Wheels

Permanently mount the wheels to the axle. You can do this by torch brazing or using the appropriate adhesive or two-stage epoxy to attach the wheel axle loops to the axle of your toy project.

After the wheels have been mounted, you can paint them or rubberize them (as shown), or wrap them with a rubber band.