The issue is one of the

The issue is one of the Bachmanns use HO components and the San Juan use real narrow guage settings,. The main issue we have had is even after swapping couplers it seems that using narrow on30 trucks on the San Juan cars is that the wheels don't clear the truss rods and we had to do a little selective weeding on the ends of the rods to get the trucks to turn.  BTW we upgraded the Bachmanns to ON3 couplers from HO.  Russ

Coupler height

So , How do you go about converting the coupler height for On30. There seems to be a huge difference between the heights. Is there an instruction sheet on what needs to be done? I feel that I have made a huge mistake by going with Bachmann On30.

What is your particular aim/mission?

Dear Rob,

The issue is that B'mann run "HO standard" (Kadee?) height, whereas SJ stick staunchly to "On3 height" despite running 30" gauge. This has been a point of debate on the On30 and On30Conspiracy Yahoogroups for years now. Unfortunately like many things in Model RRing, there's no "one size fits all" answer, just each modeller working out which compromises best fit their particular needs:

- If "3' Colorado" is your driving motivation, then migrating the B'mann gear to "On3 coupler height" will likely cover your needs. Not difficult, note that the "On3 inspired" models offered by B'mann (first released Jackson & Sharp passenger cars, OR&W box/gon/flats) already have draftgear with built-in "higher slot/mounting surface" option, ready for the coupling to be mounted at/near "On3 height".

Mechanically it will work fine, just means that any B'mann models will need coupler mods before use.
(wouldn't be the first modeller to only mod one end of a B'mann box or gon, and use it as a "match car")

NB that many B'mann rod-type locos pose larger challenges in coversion to On3 coupler height, not insurmountable but certainly more difficult than the range of pass and freight cars.

- If "out of box model equipment compatibility" is more important to you,
and the majority of the fleet is B'mann,
then mounting a stock Kadee #5 or similar to the bottom draftgear box plate of the SJ car will give you a mechanically compatible coupler height.

For future purchases, reccomend a quick look at the "design ethos" of the manufacturing company,
strict "Colorado 3'er"-esque manufacturers (SJ, MMI, etc) only begrudgingly offer On30 variants,
and seem almost pathologically bent on creating models which they feel they can then justifiably stand back and bloody-mindedly-say "...see, we told you it wouldn't work right..."

If the aim was/is to do "O scale Narrow Gauge", then On30 is a very functional, do-able, and cost-effective way forward. Many 10,000s of modellers worldwide, inc some Pre-Bachmann-On30(!) have trod the path before you and enjoyed the ride immensely. 

That said, as with any model scale/gauge/theme/ethos decision, the modeller has to gave a clear view of what they wish to model first, having this driving motivation clearly in mind from the outset will make determining the most-appropriate scale/gauge for the task much easier...

Related reading

http://www.railroad-line.com/forum/topic.asp?ARCHIVE=true&TOPIC_ID=7716

http://on30guy.gerenm.net/20090218/on30-freight-car-trucks-and-coupler-selection/

http://www.freerails.com/view_topic.php?id=4190&forum_id=4

http://model-railroad-hobbyist.com/node/13344

http://www.pacificcoastairlinerr.com/couplers/

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS my last On30 mission had a theme of a "what if?" 30" gauge branch of the New South Wales Govt Railways SG system. In this case, the "theme" required the NG equipment to "look clearly NSWGR in outline", as opposed to "30" gauge industrial" (IE to justify the massive gauge deviation from prototype, the rest of the model had to look "more NSWGR than NSWGR").

As a result, I consciously elected to use a completely non-spec "higher than HO/typical On30" coupler height and Kadee S-scale couplers. It's still "On30" by the numbers, but the impression was of a much more "hefty" NG operation, which suited the NSWGR "theme"...

​https://www.youtube.com/watch?v=h3cmV_S8-iw

​https://www.youtube.com/watch?v=q0kfeW7DcYM

AMS

Similar issue with AMS. Great looking cars with nearly incompatable couplers. I actually like them much more than the B'man and will raise the box and replace with Kadee's. 

Like the Prof says, the engines are another matter. For now the trains run for fun. When I get to the point that thare is enough done to operate the trains I'll have to quite fishing and cut bait. One thing at a time.

Neil Erickson, Hawaii 

Lots to think about

Thanks Prof for the lowdown on the High up coupler situation. I have purchased a lot of  Bachmann On30 locomotives and some rolling stock over the years. I haven't laid ( Flex ) much track at this point so wouldn't be against going over to On3. I have some thinking to do. In the meantime I will be checking out the links you posted.

BTW Bachmann height is OK for "REAL" 30"gauge railways

Hi al,

the HO scale height actually scales out correctly for the coupler heght on real 30" gauge railways

On30 is just On3 with different trucks, for some...

AMS just puts axles onto their cars that are spaced for HO, and they use the exact same car as they do for On3 otherwise. Take a good look, the molded brake rigging on the trucks doesn't line up with the wheels on the On30/HO spaced axles at all.

I have one AMS coach, which is orders of magnitude better than the Bachmann 'shorty' coaches (I had 6 Bachmann coaches at one point, I have sold all but one once I got my AMS coach and compared them, and I'm thinking of turning the final Bachmann coach into a structure instead). It has a On30 coupler, but I can couple it to my Bachmann then-wheelers with no problems. I haven't tried a mixed train yet but if I encounter any problems, I have too many On30 Bachmann cars and locos to do anything but swap the couplers out on the AMS coach.

I haven't seen any of their freight cars but I'm not surprised to see that the couplers don't line up, though I'd never given it any thought until now. Glad to know that now, as if I decide to buy some, I now will know what to expect.

But yeah, it stinks that a "On30" car doesn't line up with the established On30 standards.

I agree that there aren't any other alternatives for decent looking tank cars in On30. I'm lucky, I guess, in that the RR I model no longer had any tank cars to speak of by the time I'm modeling that RR...