Model On2 couplers added from MaineOn2FAQ-Gen: updated 04-Jan-2014
Way back in November 2000, Bill Kerr wrote, in response to an enquiry on the Yahoo! group: traditionally, Kadee #5 couplers are the standard choice for Maine On2, but I suspect there will be a move to the Sergent “S” scale coupler. See Trevor Marshal’s evaluation below for using Sergent couplers.
Coupler height should be set for coupler center to be 16-17″ above rail height. There is a coupler height gauge made by AMB’s John Hitzeman.
In response to a Yahoo! group enquiry asking for clarification about coupler heights in 2009, Terry Smith wrote:
On2;- I build my own On2 cars to the prototype derived dimension of 18″ from the underside of the underframe to the rail head………and then I bung an HO Kadee coupler on each end……it works for me and seems to match the brass loco’s that I have. I don’t refer to the NMRA Standard for this, no need to.
Maine style On30;- based on my past experience as a small scale manufacturer, then all those On30 customers who had real votes (ie dollar bills) chose to build their On30 cars at a scale 21″ underside of the underframe to the rail head dimension and floor mount their couplings which then
matched with the rest of their On30 stock.
Definitions; I find it far simpler to define an underfloor height as a coupler mounting surface and then mount the coupler than work to a rather nebulous and complicated centre of knuckle height.
In 2013 Terry noted that the NMRA correct coupler height will result from using the proper car floor to rail dimension of 18″ (prototype) or .375″ (model) and normal Kadee HO couplers (#5 and similar) in their normal draft gear/boxes mounted with their topsides against the floor.
Mark Hall wrote a good article of representing prototypical coupler boxes when using Kadee couplers in M2FM 1989 Vol 21.
In May 2013 Terry Smith posted to the MaineOn2 board; - In the many discussions over the years about what couplers were used on the Maine Two Footers and their sizes and what coupler to use with On2 models, the one thing that mildly concerned me was that I had never thought that the Kadee HO couplers I use actually look out of place on my own stock in comparison with the full size Maine Two Foot cars that I had seen at Edaville, Portland and other places, or with various published historical photo’s in standard texts.
I have now finally managed to print out an end-on photograph of one of my own boxcar models with approximately the same perspective as some pictures of the full size car taken at Edaville and the earlier historical photographs from the B&SR. The ratios of boxcar width to coupler knuckle heights in the photographs are;-
It seems to me that the standard HO Kadee coupler is a pretty good match sizewise for those fitted to the B&SR Boxcars,
For what it’s worth,
Shown below are Terry’s photos of (L) one of his models with a Kadee coupler and (R) prototype car at Edaville.
The Kadee #5 knuckle measures 0.146″ top to bottom, this is equivalent to 7″ full size in US O scale. The knuckle may be oversize for HO scale, but seems to be the right size for On2. Update 02-01-2014: note that a recent search through the past messages of the Yahoo! group has shown that the height of the knuckle of the 3/4 MCB coupler most likely to have been used on the prototype is 6 3/4″ or 0.141″ in US O scale, so the Kadee #5 is pretty darn close!
Trevor Marshall’s evaluation of Sergent Couplers.
This picture shows Trevor’s model (based on a SR&RL prototype) fitted with the scale HO Sergent coupler.
This picture (same model as above) shows how neatly the scale HO Sergent coupler fits between the wheels of the Grandt Line freight truck.
This picture shows one of Trevor’s caboose’s fitted with “S” scale Sergent couplers.
Trevor wrote (back in 2004 0r 2005);- “I’m very pleased with the appearance. The coupler head scales out to about 10″ square, which looks about right. I even add a small piece of chain between the coupler and the cut lever – there’s space near the back of the top of the coupler head to drill a small hole and anchor the chain with an HO scale eyebolt. In doing tests with these, I did note that using Sergents seriously affects layout design – it will force you to keep everything within easy reach because you need to be able to reach equipment for coupling as well as uncoupling. There are benefits to this, however:
1 – If everything’s within coupling reach, it’s also within reach for building and maintaining track, cleaning track, etc. 2 – The need to open a knuckle before coupling increases the amount of work the crew does, which takes time and therefore makes the run seem longer (something from which all layouts can benefit). 3 – The Sergents are just more realistic. They’d be incredibly frustrating on a large, operations oriented layout (like an HO club layout with several hundred cars to move in a session)…. but who in On2 is doing that?
As for height, I use a little laser cut coupler height gauge made by AMB’s John Hitzeman. I’ve attached a Sergent coupler to the top of it (without the ball bearing), and use this to set the height on my equipment. Usually, this requires a spacer between the locomotive frame and the coupler box. I’ve been building my own coupler boxes, as I’ve yet to find one that these couplers fit into. The hole in the coupler shaft is smaller than that in a Kadee #5, so the plastic tube in a #5 coupler box is too big to fit through the Sergent coupler. Some good coupler boxes (laser cut acrylic, perhaps, John?) would be a great benefit for these. Trevor in Toronto.
(Update: Feb 2005) “Having tried my own coupler boxes for several months now, I decided to try some Kadee coupler boxes. The boxes for Kadee’s S std gauge/On3 couplers (same box) fit the Sergent’s perfectly. By cutting them to discard everything behind the two mounting holes, they’ll fit between the wheels of an On2 car and not interfere with the outboard axle. The Kadee S boxes provide better coupler swing and are easier to install. I was able to bulk order 100 boxes directly from Kadee. (www.kadee.com) Trevor in Toronto
More thoughts on Couplers from Trevor Marshall, including a comparison between Kadees and Sergents, originally posted the MaineOn2 group 25th April 2006
Those interested in a scale size coupler as operating on the Maine lines during their heyday should probably engage in further research before jumping on the Sergent S scale bandwagon (as attractive as that seems).
One thing that I haven’t seen mentioned in this coupler debate is the giant spring on the side of every Kadee coupler, that controls the knuckle. I find it amusing that people are getting twisted up about a scale inch here or there, but are apparently quite happy to ignore the big spring. And that brings me to a larger issue that I haven’t seen addressed, and that’s this: Before picking a coupler, decide what it is you want to do with the model when it’s done. Each style of coupler has pros and cons… I’ll list a few, based on my experience with both.
Assembly/Installation: - Kadee wins here, hands down. They’re easy and quick to assemble and install. This may be important to those planning to build a lot of rolling stock. Sergents take about 45 minutes per pair to build – and most people should plan on rebuilding their first half-dozen pairs because you’ll get better at doing them, and the first ones won’t operate as reliably as the rest.
Appearance: – Sergent wins, hands down. As I noted above, knuckle couplers – whether 1/2 MCB, 3/4 MCB, Type D, Type E, or what have you – don’t have large springs on their sides. Even if the Sergents are a little too large, or a little too small, not having a spring on the side more than makes up for it, appearance-wise.
Operation of the coupler itself: – Kadee gets a slight nod here, as they are pretty damn reliable right out of the box. But if you take your time and work carefully on building the Sergents, they can operate very, very well. Your success depends on your own skill.
Operation on the layout: – This depends on what your design goals are…
KADEE LAYOUTS – If you are building an operations-intensive layout – let’s say you’re doing Farmington to Phillips, with staging north of Phillips and staging northeast of Strong – you will be better off with Kadees. You’ll be shuffling a lot of cars, and the need to open knuckles on the Sergents can become tiring pretty quickly.
– If you are building a layout that has car-spotting locations that are more than 18″ from the aisle, or that are inside buildings, you’ll want to use Kadees. Obviously, this depends on a number of factors, including layout height, the length of your arm, and how good your eyes are. But in general, with Sergents you need to be able to get your head directly above the couplers you want to couple or uncouple, every time. Sergents have a smaller gathering range than Kadees, so you must open the knuckle(s) then carefully check the alignment of the couplers before trying to couple. If you can’t reach and can’t see to do this, you’ll experience no end of frustration. Kadees have a better gathering range, couple automatically, and can be uncoupled using under-track magnets so one doesn’t have to reach into the layout to make them work.
SERGENT LAYOUTS – If you are building a smaller, more relaxed layout – for instance, the KCRR – then the extra work that Sergents require (opening the knuckles, aligning the couplers) actually becomes more play value. Prototype railroads have to open knuckles, manually align couplers, etc., so it’s more realistic, too. Sergents slow down your operations. It’s impossible to bang the cars about with Sergents, whereas with Kadees one can do jackrabbit-like changes in direction over a magnet and kick cars all afternoon. Sergents, manually writing switch lists, train orders and other paperwork, and installing and learning to properly use sound systems (DCC or analog) help stretch out an operating session and turn it from a puzzle to a re-enactment of real life. For a small layout, the extra work involved with all of this will make a 15 minute operating session take an hour. Some people may like that, others will not. Decide which type of person you are before picking couplers.
– Trevor (using Sergent S scale couplers on his On2 equipment) in Toronto
Editors note dated 04 January 2014: Trevor Marshall is currently modelling a CN branch line is S scale, standard gauge, and using Kadee couplers for reliability. This may well change if Sergents produce a more “robust” S scale coupler for home assembly or factory assembled couplers. Please note that “robust” is used here in its manufacturing engineering (Statistical Process Control) context, rather than the more common physical meaning of hefty or over-large.
Update December 2013: there is now a Sergent couplers Yahoo! group;-
and Sergent now have a more accurately moulded S scale coupler on the market.
(Trevor Marshall had reported having difficulties with reliably assembling the earlier version of this coupling, so much so that he opted for the pre-assembled scale HO version (visibly undersized) for his MaineOn2 layout). See http://themodelrailwayshow.com/cn1950s/?p=4122 for pictures, or http://www.sergentengineering.com/ for more information.