Frank S and C-Bag,
I learned a lot from building with the Gilbert Erector sets back in the 1950's and early 60's. I would have several projects in progress on my bedroom floor. I enjoyed making cantilevered bridges and cranes and all gear driven either by a hand crank or motors. Wonderful ways to first image something and then build it with the erector sets. My mom refused to vacuum my room because she didn't want to vacuum up the nuts and bolts. I guess a few of these parts chewed up the vacuum rotary head so my room was off limits.
Thanks for the memories, Paul