Converting Bachmann On30 to O 3R?

That's because they would look VERY strange.  It is not just a matter swapping wheelsets.  On30 and On3 are based on narrow gauge prototypes, which are MUCH smaller than their standard gauge brothers.

The typical O gauge truck is wider than the Bachmann On30 cars.  There's also the longer wheelbase of a standard O gauge truck to consider. 

The result would look more akin to a monster truck than a freight or passenger car.

When converting On30 to On3, the differerence is only a scale 6" in gauge.  On30 to O gauge, the difference is a scale 30" in gauge, or doubling On30's gauge.

Rusty

To reinforce what Allan and Rusty have said, here are some side-by-side comparisons of On30 equipment and standard O gauge. You can picture what the results would be by imagining the standard gauge wheels under the narrow gauge engine and car bodies.

Bachmann chose extremely small narrow gauge prototypes upon which to base their On30 line.

I like Rusty's monster truck comparison; it's right on the mark.

Jim

Westside models made a heisler with O and On3 trucks.

Third rail pickups and bigger flanged wheels could be added if wanted.

They can be converted back by switching trucks.

They are easily found used on EBAY.

Here is a photo of one, much prettier than mine.

Heisler with O scale trucks installed, On3 trucks loose.

(not my Heisler )

My Heisler set up for On3

I had a pair of those Heislers back in my 2-rail days - very nice models. I had the standard gauge versions. Ran very smoothly; I wish I had kept them.

If you placed one of those Westsides next to a Bachmann On30 Heisler, again it would dwarf the Bachmann.

I would recommend searching out one of those Westsides for anyone wanting a standard gauge Heisler at a relatively reasonable price.

A 3-railer could add a small mountain division using 2 rail O gauge track with maybe a switchback-type plan to conserve space. I never experimented to see how tight a curve the Westside could take.

Jim

Thanks, all...I had just looked at the Bachmann version in passing and not picked one

up..the Westside Heisler I have seen offered from time to time and was aware it was offered with two sets of trucks, but since it was brass and presumed expensive, was afraid a three rail conversion would prove to demand a machine shop, if I sprang for one.  (did not realize there was that much of a size disparity with Bachmann.....will have to fish out one of their cars and see about the truck switch.  From the loco photo comparisons, maybe a car will need considerable widening in the kitbash. Those two tank engines shown together in the photo above make it hard to believe two guys who'd fit in the cab of the MTH, could fit in the Bachmann, i.e., are they really the same scale)  Foiled again....

Maybe not foiled!  Instead of shooting from the hip, I pulled out a kit for a

Bachmann On30 combine and a T-boilered Shay.  Also went through some books

on "ghost" railroads with assorted tea kettles and dinky equipment.  I plunked

the two kits down on 3 rail, and they do not look grotesque, or any more unusual

than, say, the East Broad Top cars they used to switch back and forth from narrow

gauge trucks to standard.  Above photo of the two tanks now leaves me wondering if the MTH tank is another 99 ton model of a 44 tonner like those from Lionel and Williams.

I also dug out various sets of trucks that would go under the combine, such as

Grasse River short wheelbase arch bars, and old Auel archbars...but think kit's sideframes could be widened if a small diameter wheelset can be found.  Examples

of prototype conversions where the road was widened from narrow gauge to standard, and so was the equipment, are in the literature.

The T-boilered Shay has another problem, the bottom of the boiler...would touch

the third rail, unless larger diameter wheel trucks can be used.  It would be a much

more difficult conversion, from the rewiring...and converting it to wider, larger flanged

trucks, which is why I would prefer to work with a Heisler.

I will do this combine as my next project, to verify it can be done.

Colorado,

You're right that the MTH 0-4-0 looks to have had steroids in its past, while the little Porter is among the smallest prototypes I've ever seen. Scaling out most of the On30 equipment, they seem to be based on 2-foot gaugers which were extremely small by design.

You're right that searching out some of the smaller standard gauge trucks from the 2-rail world might be the best bet to make the rolling stock at all believable. But, I think any extensive rebuilding to widen them would be more trouble than just scratchbuilding new larger models. If anything, I would stay away from the full-size pizza cutter 3 rail flanges and go with some older 2-rail wheelsets. Many have an in-between flange size that operates well on 3-rail track and switches.

As far as the Shays, Heislers, or Climaxes are all concerned, they would be real challenges. Just imagining the appearance of a standard roller pickup under one of those gives some idea of the work needed.

But, I'm sure you're up to the challenge. It wouldn't be fun if it were always easy! Looking forward to progress reports.

Jim