View Full Version : Bar tread tire jig

Lee Schierer
11-17-2015, 9:42 PM
I needed to make a lot of small tractors as wedding favors for my niece. I found a plan for a simple tractor that I could scale down to the size I wanted. After an extensive search of the internet for bar tread tires like those used on a tractor I had zero success. I gave it some thought and came up with a plan to make my own wheels with a bar tread type design.

I made wheel blanks from 1/4" thick soft maple using a 1-1/2" hole saw. Then I could put them on my drill press using a 1/4-20 bolt and a couple of nuts to sand them smooth 4 at a time. I would need two blanks for each wheel. The jig I made is actually pretty simple. The heart of the jig is an indexing block, shown below.
This indexing block has 25 holes which gives me the right spacing and width for cuts using a 1/8" kerf blade for a 2-1/4" finished wheel. The back board of the jig has a center hole and a sliding pin that fits into the indexing holes. I used a pop rivet for the slide for the pin and the "nail" of the pop rivet for the shot pin. I had to reshape the head of the nail to have a taper so it would go into the holes in the index block.

The back board mounts on my crosscut guide which is angled 22.5 degrees to the blade and the vertical centerline of the two wheel halves being cut is centered on the blade teeth.

I mount two left or two right wheel halves at a time to the index block using small bits of double sided tape to keep the three pieces aligned during the cutting operation. I use a 1/4-20 screw and a wing nut to hold the wheel pieces and the index wheel to the face of the back board. I set the ATB raker saw blade at a height of .430" above the table. I insert the pin in the zero hole to start and make a cut.

As each cut is made, I pull the pin back, rotate the wheel one position and make the next cut. This happens 25 times for each two wheel halves.

I cut a bunch of left wheel halves and then angle the jig the other way, aligned the same way tot he blade to make an equal number of right wheel halves. Once I have the halves made, I can start gluing up wheels using one left and one right to make each wheel. Once the glue dries I chuck the wheels up on my drill press one at a time and use a broken sander belt to round over the edges and clean up any fuzzy bits left by cutting. A finished wheel looks like this.

After making a few wheels, I found that gripping the pin repeatedly was starting to hurt my fingers so I added a wooden knob that I glued onto the nail for a better gripping surface.

The completed tractor looks like this.

Ken Fitzgerald
11-17-2015, 10:50 PM
You surely must love that niece! Well done Lee!

Walter Plummer
11-18-2015, 6:05 PM
Way to nice for "Favors". Very nice work.

Lee Schierer
11-19-2015, 3:22 PM
You surely must love that niece! Well done Lee!

She asked me to make a "few for the young kids", now it has morphed into at least 36. It may turn into her wedding present.:D