Installing a ball bearing

OR, you could always cut them exact and groove for a snapring... (after drilling the bearing access holes :)

That was a learning experience!

Thanks to those who helped, especially Ned for this advice on measuring and Gunner for a simpler way to extract the bearings than I had planned on.

Three of the bearings press into the wheels with heavy thumb pressure, the fourth is loose by less than 0.001".

-jsw