RE: Are there any Fn3 or Fn2 builders here?/ Is it possible to build F scale to run on HO track?
Dave:
Oh, yeah, I'm aware.

I spent days putting numbers, Fn3, Fn2, to my proposed layout and bugging the guys (nice ones, lucky for me) to help me with the proper teminology.
There are several reasons for the multi-ga setup: I'm an ORG /DesktopModules/NTForums/themes/mls/emoticons/sick.gif (Old, Retired Guy)and I've wanted to build a RR for decades. (Literally: we had to tear down our nice Lionel when the first baby came along.) So for years I'd think about a layout when I had time to do so. Retired tool 'n die maker.
I stumbled across G Gauge by accident after having sold a collection of HO put away 'for retirement'. I couldn't see the stuff! So tiny. So, what to do? HO and downward was too small. S? Pretty expensive. Lionel? Nah, been there, done that. I want to build my stuff. O ga? Ehh... ouch, the prices. Then I saw the G stuff and as soon as I realized I could actually build, oh boy.
I had to move indoors due to health reasons before I ever got a start, the first year. So I'll have a small PP layout. I've always wanted dual gauge, and the Gurus of G Scale assure me O is the way to go. I got some O track and laid it inside a piece of G, and, yep. Then I got to thinking about a mine. I wanted narrow NG. Some more asking, searching and I came up with S ga (18" @20.3)
So, would that be Fn18, or Fn1-1/2? I haven't asked yet. (Letting 'em rest.) What do you think?
Oh, FWIW, I toyed with the notion of tinplate Lionel O ga, but in the end I didn't. The desire to scratchbuild won out.
Thanks for the headzup.
Les