Wheel hubs and cog wheel.

To get the wheel hubs to fit into the cog wheel hubs, took a bit of work, last time I used a cutting bit in a drill press to make the opening large enough. I've been wondering how I was going to do this.

enlarging the cog wheel opening.

Here's the answer. The only hole-saw I had that was appropriate was 1/8 of an inch too small. The answer? Sandpaper. LOL, took way less time then the cutting bit.