http://backyardrollercoasters.org/
I painted my workhorse "Smaug the Terrible" backyard roller coaster bogie cart, upgraded the bearings, added a thrust bearing, and ground the wheels round.
I tried to show how the forward and aft wheel bogies work.
Additionally, there were a lot of questions about the other BYRCs in my yard, so I added a tour of all three tracks.