Since I am fairly new to the hobby I would like to know the difference between ON30 and ON3
Both are ‘O scale’ - only the track gauge is different. The models are built to 1/4"=1’ scale(1:48th).
o - On30 is designed to run on standard HO track(about 5/8").
o - On3 is designed to run on scale 3’ trackage(about 3/4").
The idea of On30 is that commercial HO track can be used …
Jim Bernier
have know idea lets hope On30Shay chimes in on this thread!!
On30 means O scale (1/4" = 1’-0") narrow gauge with a track gauge (rail spacing) of 30 inches or 2 1/2 feet.
On3 is the same as above except it has a track gauge of 3 feet or 36 inches.
On30 is popular as you can use HO (which scales out to almost 30" in O scale) track components rather than the more expensive or handlaid track needed for On3.
And archaic MR still calls this popular scale On2-1/2.
No to TUNA HALF!
Bob Boudreau
I don’t think that’s “archaic”. They have a particular mindset - they apparently like to think in “feet” rather than “inches”. On3 would be correct because it’s 3 “feet”, but On30 would be inconsistent because it’s 30 “inches”.[:D]
Piedsou has it right. anything with the n3 suffix represents three foot (36") gauge. Anything with n30 as a suffix represents 30" gauge. On30 breaks down like this: O=O scale, n=narrow gauge and 30=30"gauge. It just so happens that in O scale, 30" is the same gauge as standard HO track. On30 used to be referred to as On2 1/2, As Bob pointed out. The 2 1/2 of course represents 30" or 2 1/2 foot gauge. It can get confusing when looking at narrow gauge stuff. Just remember gauge is the distance between the rails, and scale is the actual size of what’s being modeled. The two are not always the same. I have a good friend who’s really out there with narrow gauge stuff. He’s starting to get into 7/8n2. Get you some of that. That’s 7/8 scale n= narrow gauge 2= of course two foot gauge rail. Here’s his site: http://www.dawgstrainhouse.com/ There’s a lot of good information there. He models all kinda narrow gauge stuff. One of his Gn15 (G scale narrow gauge 15" rail) was featured on Carl Arendt’s Micro layout page. He was featured in the November scrapbook, I believe. I went from HO to On30 and haven’t looked back. Lots of freedom of expression. If you scratchbuild something, chances are there was a prototype.
To be consistent, if you want to use On30, you would have to say that On3 is really On36 - the difference, of course, being 6 inches![:D]
That’s right! But then, what’s consistant about narrow gauge railroads?!?!?!?!
“Consistency is the hobgoblion of small minds.”
[:D]
And don’t forget On16.5 
LMAO. I think that’s kinda pushin it.
On30 is an old idea of putting big cabs on too small HO mechanisms and calling them real narrow gauge. Not that anything is wrong with that point of view. Bachmann brought out their On16.5 equipment, which would have been better served with that name. It was not “true” On30 because it represented real narrow gauge equipment. It was built to run on HO track to save tooling new track because the original train set was designed for Department 56 porcelain structures. It allowed the normal hobbyist to enter the “elite” world of narrow gauge and model 1/4 in scale narrow gauge.
I used to model in On16.5 but have sinced moved on. I found too much negativity in the narrow gauge world and especially “On30”. Too many “experts” long on wind and short on knowledge. My old “On30” site is at:
http://www.pacificcoastairlinerr.com/on30/main_page/
Thank you if you visit
Harold
I started modeling in On3 over 15 years ago. Due to the extremely high cost of motive power I never had a loco. When Bachmann came out with their affordable and high-quality On30 locos, I switched to On30 and have never looked back. On30 has opened the realm of O scale narrow gauge modeling to the common person. It offers a lot of freedom of expression and quality equipment with the convenience and economy of HO.