Two days after Christmas my daughter broke a piece on her new RC car. My immediate thought was that this might be a good use for my 3D printer. The tiny wheel axle was pretty complicated to replicate and I had to use a caliper to make the original measurements. A few hours later and I had a mostly decent Tinkercad model built out that I could print. I was pretty impressed on how close it was to the original. Outside of a quick drill press trip to expand one of the hole for the axle, everything came out perfectly on the first print.