Author Topic: Body or truck mounted coupler  (Read 2610 times)

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engineshop

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Body or truck mounted coupler
« on: October 26, 2007, 11:34:09 AM »
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Did anybody ever body mount a coupler and the car just did no work even with radius 18".
A list of freight cars (brand, type) that have been successfully changed to body mounted coupler could be helpful to other modellers as well.

The only one I every did was MDC Roundhouse Mech. Reefer (now sold by Athearn and I don't know if they changed something that would make it a problem)


rschaffter

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Re: Body or truck mounted coupler
« Reply #1 on: October 26, 2007, 10:28:59 PM »
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I have bodymounted couplers on over 200 cars, as well as adding NMRA compliant wheelsets.  33' cars will operate on 6 3/4" radius, 40' cars will operate on 9 3/4" curves and 50' cars on 12" without problems. The only ones in my era (1950s) that are problematic are some tankers and hoppers that don't have the center sill extending to the end.  N Scale of Nevada makes adapters for some hoppers-  www.nsn-2.com (they are currently redesigning their website, so they may or may not be listed)

Walkercolt

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Re: Body or truck mounted coupler
« Reply #2 on: October 27, 2007, 01:37:48 AM »
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One problem in body mounting N-scale couplers, is coupler height. Sometimes it's neccessary to modify the end of a car to get the coupler height correct. This can be quite a challenge with some cars. Rod mentioned the problems with hopper cars and tankers too. N-scale was designed for truck-mounted couplers. The fact that we can modify this should be looked at as a bonus, like a Christmas surprise package. What really gets hairy is when you try to lower the ride height of a car, by lowering the bolster, then trying to body-mount a coupler at the correct height. Then you try using Z-scale body-mount couplers for a more "realistic" look, but the physics says you can't make a smaller coupler as strong, so now you can't run 115 car unit coal trains, which is one of N-scale's strong points. About then, you start to ask yourself "is this fun?" ::) Understand, I'm basically an N-TRAKer, and we want reliability above scale fidelity, and I'm not knocking anybody who wants to body mount, lower cars, and super-detail things, but I haven't seen those kinds of cars run for 8-10 hours at a time in 80+ car trains without uncoupling, or other problems. I guess it just depends on what turns you on.

inkaneer

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Re: Body or truck mounted coupler
« Reply #3 on: October 27, 2007, 10:47:46 AM »
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I think body mounting couplers in N scale is overkill.  Truck mounted couplers in HO were an issue way back in the days of the X2f or horn-hook coupler.  The coupler would cause car trucks to skew due to the diagonal mating faces of the coupler.  A switch to body mounting the coupler was an easy solution for most of the problem.  Along about that same time the KD coupler became the defacto standard and manufacturers incorporated a standard coupler box on their underframes.  In N the original Rapido coupler did not have the diagonal mating surfaces of the HO X2f with its side to side movement.  The Rapido coupler had a vertical movement with square mating surfaces.  Body mounting couplers entails a whole new set of problems in setting the couplers at the correct height.  Lowering the car body also complicates the matter.  The real question is is it really needed?  I think before one starts  this project they should first make sure their cars are proberly weighted and take a look at your trackwork.  How good is it and how sharp are your curves?   Pushing a string of cars around a curve with light weight cars in the middle is asking for disaster.   The odds of a derailment go up the sharper the curve. 

3rdrail

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Re: Body or truck mounted coupler
« Reply #4 on: October 27, 2007, 11:16:14 AM »
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I learned from experience many years ago that your fleet has to be all one way or the other, especially of you have sharp curves. I converted my first 15 or so cars to body mounts and found they would not couple except on straight track, of which I had very little, and if run with cars with truck mounted couplers, would cause derailments.

Since I had curves down to  7", I went back to truck mounted couplers.
« Last Edit: October 27, 2007, 04:53:20 PM by 3rdrail »

ednadolski

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Re: Body or truck mounted coupler
« Reply #5 on: October 27, 2007, 04:38:44 PM »
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The real question is is it really needed?

For what I am doing, the answer appears to be yes.  I run DPUs and mid-train helpers, when these have to push a train up a grade then the truck-mounts just don't cut it -- they skew and derail as soon as they go under even moderate compression.  Over-weighting the cars doesn't help much, and just reduces the overall train length that can be run up grade.  Pizza-cutter flanges are also counterproductive, since they increase drag and aren't terribly effective without the extra weight.  My grades are 2%-3% and curves are 16" or larger, which is not excessively steep/tight.

I don't need to have them all one way or the other -- just the cars that are going to be pushed by the DPU/helper locos.  Trailing cars won't have their couplers in compression and don't need the body-mounts for that.

Lowering the carbody also helps improve stability, tho I don't know of anyone quantifying that.  For me, eliminating the "Lionel Look" of the high-riders is sufficient justification.  :)


RS-27

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Re: Body or truck mounted coupler
« Reply #6 on: October 29, 2007, 03:47:28 AM »
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If you have a high level layout, 4.5 to 5', you can't see more than 30 cars or so.  So if you aren't Ntrakin, those issues (train length, coupler strength, etc) aren't there.  But tiptoeing cars will look like crap. En Pointe is fine for ballet, but running trains is a world apart.

Bob in IDaho, who's imagination has been seduced by John Armstronsg 'Festung Europa'... look it up in your Funk & Wagnals/ Kalmbach books

rschaffter

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Re: Body or truck mounted coupler
« Reply #7 on: October 29, 2007, 08:45:40 PM »
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I think body mounting couplers in N scale is overkill.  Truck mounted couplers in HO were an issue way back in the days of the X2f or horn-hook coupler.  The coupler would cause car trucks to skew due to the diagonal mating faces of the coupler....

True.  Unfortunately, unlike the H0 Kadee coupler which couples/uncouples by means of movable knuckle, the MTL coupler uncouples by swiveling the coupler to one side-just like the X2f.  This results in similar skewing of the trucks during pushing.

Also X2fs were originally bodymounted-H0 started out as a "craftsman's scale", and couplers were bodymounted.  Mantua (Tyco) released their Talgo trucks in '58, IIRC, just in time to compete with the slot car craze.

wm3798

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Re: Body or truck mounted coupler
« Reply #8 on: October 29, 2007, 10:52:15 PM »
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I started cutting off Accumate coupler boxes from the trucks and using the severed boxes for body mounts.  All of my Atlas 55 tonners have been converted, with the help of a dab of CA adhesive.  I've also converted my Intermountain covered hoppers, adding a styrene shim to hold the draft gear.

My main concern was the coupling distance, but I've noticed there are far fewer derailments on those cars than on those with truck mounts.

Lee
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Lee Weldon www.wmrywesternlines.net

GaryN

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Re: Body or truck mounted coupler
« Reply #9 on: October 30, 2007, 12:09:47 AM »
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Quote
I've also converted my Intermountain covered hoppers, adding a styrene shim to hold the draft gear.
What thickness is the styrene shim?

wm3798

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Re: Body or truck mounted coupler
« Reply #10 on: October 30, 2007, 07:29:27 AM »
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Uh... dunno.  I think .030, but the stuff came out of the scrap box, not the package...

Lee
Rockin' It Old School

Lee Weldon www.wmrywesternlines.net

ednadolski

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Re: Body or truck mounted coupler
« Reply #11 on: October 30, 2007, 09:58:34 AM »
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If you have a high level layout, 4.5 to 5', you can't see more than 30 cars or so.  So if you aren't Ntrakin, those issues (train length, coupler strength, etc) aren't there.  But tiptoeing cars will look like crap. En Pointe is fine for ballet, but running trains is a world apart.

I fully agree about the tiptoeing, tho my layout is Tehachapi Loop, so for me 30+ cars is the rule rather than the exception:




The longest I can run is almost 40 cars before they start stringlining on the sharper curves if have all the power at the head end.   Thus the need for DPUs and body-mount couplers.

Currently my staging yards limit me to about 35 cars + 4 engines anyway, but I do have plans to build a larger version & longer trains.  First I first have to get over being "backdrop challenged"  :)



GaryN

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Re: Body or truck mounted coupler
« Reply #12 on: November 01, 2007, 01:07:23 AM »
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Quote
Uh... dunno.  I think .030, but the stuff came out of the scrap box, not the package...

Lee
thx.  I used 0.020 and it seemed to flex when I installed the body mounted 905 Z coupler.

Chulvis

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Re: Body or truck mounted coupler
« Reply #13 on: November 01, 2007, 06:55:23 AM »
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I fully agree about the tiptoeing, tho my layout is Tehachapi Loop, so for me 30+ cars is the rule rather than the exception:

ednadolski, you have the monument sign on your layout. Nice Touch!