Make a Wooden Drive Wheel

How I made a wooden drive wheel my Dirt Cheap 2 x 72" Belt Grinder project.

I am going to manufacture a simple wheel for my 3/4 horsepower 2 pole (3600 RPM) ODP pump motor. Unlike the typical 5/8" keyed shaft, this motor has a 1/2" NF (National Fine thread) shaft where the pump impeller was screwed on. A bolt welded on to a 1/2" NF nut may work to my advantage here and the right-hand thread tightens the nut with the CCW direction of the motor.

I'd like the drive wheel to be 2-1/4" wide and three pieces of 3/4" medium density fiberboard (MDF) will stack up to this. The diameter will be 3.82" and the unloaded belt will run at 3600 surface feet per minute, which is a good speed for a broad range of belts and applications.

I set my compass to 2" and drew a center line down some 3/4" MDF. I scribed three circles leaving a little room between the circles to cut them out.

Now I drill a 5/16" hole exactly where the point of the compass marked the wood.
On the bandsaw I slowly cut outside the line.
Here is one circle done.

Once I had all three cut, I got some good indoor/outdoor wood glue.
 I put a length of 5/16" threaded rod through the first circle and smeared some glue on and made a stack of the three circles. 

With a few washers and nuts and tightened the discs together. Expect some glue to ooze out.

Now with the clamps I gave the block a squeeze and let sit overnight.

 I mounted the wheel on the motor and used a chisel to true the face. Resting the chisel against the edge of the workbench.

Some black paint and we're good to go.

Here's a video I made that shows the construction of the wheel.

OK, so your motor has a different shaft?  There are some inexpensive products that can make your life easier.

This is tapered bushing. They come in common shaft sizes like 1/2", 5/8" and 3/4" for usually under $10. With this bushing you can fit any just about diameter of wooden wheel you want to make to your motor shaft.

I have another smaller motor with a 1/2" shaft with a flat for a set screw on it. With some 3/4" DOM tube (which has a 1/2" inside diameter) and a 1/2" large flat washer I made a kind of bushing suitable for the little motor's 1/2" horsepower capacity.

 I cut about 3" of  DOM tubing and found a hefty 1/2" washer.
 I stacked these on a 1/2" bolt and clamped in the vise.
I hit is a few times with the welder. Then cleaned up the welded area with the angle grinder.
Now drilled and tapped for the set screw. For this one a 1/4" setscrew is okay. Fine threaded setscrew would be an improvement.
Now I drill two 3/16" holes exactly opposite about 3/8" from the outside of the washer.
 Countersink the holes for a flathead screw of your choices. The countersink is option but will give a nice flush look to the finished wheel.
Here I have mounted the adapter to the motor shaft and clamped the motor down. While it is running, I take the angle grinder and reduce any wow in the washer.

This part can now be fitted to any diameter of drive wheel you want to make.

I am working on a 6" wheel for a four pole motor. I'll post some photos when it's done.


Unknown said...

Hi howzit
I have a pool pump motor with a half inch threaded shaft on it that i would like to build a mdf drive wheel for.Should i just force the mdf to thread on the shaft and will it hold over time.

D. Comeau said...

I would use the left-hand threaded end of the shaft to help secure the wheel. Sometimes there are left-hand threaded nuts molded inside the plastic pump impeller. These can be extracted with a little heat. There should also be a shoulder in the shaft that you can use to sandwich the wheel on with.