This instructable will show you how to turn a baseball into a shift knob for your car.

Step 1: Tools and Materials

Materials

Baseball. I went with a weighted baseball I found on Amazon. There are a couple reasons to go with a weighted ball instead of a regulation ball. The construction of weighted baseballs is better for this application because of the size of the core. But also, I wanted a black baseball to better match the interior of my car and weighted baseballs come in a variety of different colors based on the weight
Threaded Slide-on Shift Adapter. My shift lever is not threaded, so I bought an adapter from TWMPerformance.com that is held in place with setscrews. You can find one here: http://www.twmshiftknobs.com/shiftknobs/knobinsert.php
5-Minute Epoxy

Tools

Drill or Drill Press
11/16" Forstner Bit - The shift adapter from TWM Performance is 3/4", so I went one size down. If you are not using the adapter, adjust the size as required. Recommend using a forstner bit vs a standard drill bit as it makes a flat bottom hole and won't catch on the string inside the ball when you drill it.
Hobby Knife

Step 2: Preparing the Baseball

Before we start drilling the baseball, there are a couple things we need to do. First, set the adapter on a table with the threaded side up. Then, place the baseball on top, making sure to align the baseball seams to reflect how you want the final product to look. I went with the four-seam fastball look.

Next, flip the the ball and adapter over and trace the outline of the adapter onto the ball.

Note: My baseball came with logos that I didn't want to keep. I was able to remove them with a bit of paint thinner. I recommend applying a bit of paint thinner to the where you will be drilling first to see how it will affect the leather.

Step 3: Preparing the Baseball Cont'd

Before we are ready to drill, we'll need to cut a hole the leather with a knife. I didn't have a hobby knife handy, so I used a pocket knife.

Cut the leather along the outline you traced in the previous step

Step 4: Drilling

Now we are almost ready to drill. Place the forstner bit on a table next to the threaded part of the adapter and apply tape to the bit to mark the depth you'll need to drill.

Now carefully drill the ball, starting slow. Once you get through the string part of the ball into the solid core, you can speed the drill up (if you are using a hand drill). Drill until the tape reaches the ball.

Step 5: Assembly

It's time to assemble your new shift knob. Make sure to clear any debris out of the baseball that's left over from the drilling. Test fit the adapter by screwing it into the ball. It will be a tight fit but you should be able to screw it all the way in.

Once you have the adapter screwed in all the way, take it out to your car and test fit the whole assembly onto your shifter. Make sure you are okay with the height of the ball. You can drill the hole a little deeper to lower the height, but make sure you don't drill so far that you ruin the integrity of the ball. I recommend not going much deeper than halfway through the ball.

Step 6: Epoxy

This next step is optional, but highly recommended to prevent issues later on. I didn't take pictures of this step, but it should be fairly self explanatory.

If you are happy with the height, unscrew the adapter from the ball. Mix up some 5-minute epoxy and coat the inside of the hole in the ball. Before the epoxy dries, screw the adapter back in. Allow the epoxy to set per the requirements of your chosen epoxy.

The first time I did this, I let the epoxy dry before I put the adapter back in, but I wasn't able to get the adapter back in without re-drilling. If you don't want to epoxy the adapter in the ball, you could probably use a tap on the dried epoxy to facilitate getting the adapter in.

Step 7: Finish!

Your brand new shift knob is now ready to be installed. Attach your stock shift boot to the adapter. Then, slide the adapter onto the shift lever and tighten up the setscrews.

Now go for a drive!