Does anyone know of a way I can modify my new MTH PRR heavy weight passenger cars so that they will negotiate my mix of 18 and 20" radius curves. I was still new in the hobby when I purchased the 5 car set and did not realize they were for 22" radius. They were never run and until I push tested one through a tunnel to check clearance did I realize there was a drag as it was negotiating the 18" radius portion of the track. I really like these and I hope someone can offer a suggstion for a fix. Thanks so much---John
[edited by admin to fix radius in subjectline]
Talgo trucks may solve your problem. The couplers are mounted on the truck instead of the body. You may have clearance problems with underbody detail in which case you'll need to remove enough detail to get the truck coupler swing you need. Also you may find long shank couplers are needed as well.
Good luck
Paul
Maybe. No guaranteed results. Check the weight of the car and add ballast if it is less than NMRA recommendations. (one ounce + a half onunce per inch of length). Check truck swing and Dremel off underbody obstructions as required. Check wheel gauge, an out of gauge wheel becomes extra ordinarily troublesome on tight curves. Install truck mount couplers. Run the cars with other equipment of the same length. A train of mixed long and short cars will have more trouble on curves than an all long car train (long locomotive too).
Might work, might not. You won't know till you try.
David Starr www.newsnorthwoods.blogspot.com
Even 20" is a pretty tight radius curve for cars of that type - even longer freight cars for that matter. One thing might help but it might be too late -- the use of easement (transition) curves. John Armstrong's book on track planning for realistic operation shows how a car that finds it a challenge to handle the transition from pure tangent to a curve of fixed radius, can in fact handle that radius if there is a transition easement into the curve. If this would mean tearing up the layout then it may be out of the question - and at the least you'd want to construct a sample bit of trackwork to see if it actually works.
And remember this as well - pushing or pulling a car through a challenging bit of trackwork is one thing. Hauling it with a locomotive -- with its own overhang and coupler issues -- can be another.
Dave Nelson
According to the MTH website they are designed for 22" radius curves. 18 is going to be quite a stretch. You might want to hold off hacking up those cars (you spent ballpark $450 of that set) and see if you can find a set of Athearn Bluebox cars (not as detailed but you might be able to squeeze them a through those curves and they can be had for much less....currently there is a Blue Box 4 car set for $32 on Ebay....)
I really think you should consider much wider radius curves. The cars will not look right on any curves beleow 30".
GARRY
HEARTLAND DIVISION, CB&Q RR
EVERYWHERE LOST; WE HUSTLE OUR CABOOSE FOR YOU
Heartland Division CB&Q I really think you should consider much wider radius curves. The cars will not look right on any curves beleow 30".
If I had to be a guessing man, the OP probably has a 4x8 layout (2013 posts looking for 4x8 track plans and stating that he only has a space for a 4x8). Since the layout is already built telling someone that they need a 30" radius is not really a feasible solution.
To the OP:
You may be able to find 4 axle trucks (which will not be prototypical for your cars) which might allow your trains to run on a tighter radius. I do not know if you will be able to get those cars to run around 18" or not. As others have mentioned there are physics involved which may prevent it. Longer Kadee Couplers might help as well. Can you post a drawing or photo of your track plan?
My next suggestion would be to sell the MTH cars and use the proceeds to buy ConCor 65' cars. ConCor sells a quality line of 65' heavyweight passenger cars in numerous road names including two PRR paint schemes. The cars are designed for operation on 18" curves.
That is usually the dilemma, either sharp curves and shorty passenger cars or broader curves and scale length passenger cars. I would be very hesitant to start chopping up expensive detailed passenger cars to get them to go around sharper curves than they were designed for. HO train cars are a bit like software, you need to read the package to see if the minimum requirements are met by the computer, or in this case, the layout.
AFAIK, all of the Athearn blue box heavyweight passenger cars are shorter than scale length, as are the steam lined cars.
Now if the OP has a 4x8 layout, it is possible to use 22 inch curves, they will fit within a 48 wide format but the passenger cars would be limited to the outer track, assuming one has a 2 track oval with 18 inch inner and 22 inch outer curves.
An alternative is if the OP can rebuild with a slightly wider layout, he could fit 22 inch inner and 24 1/2 inch outer and the passenger cars could run on both tracks.
Rio Grande. The Action Road - Focus 1977-1983
It depends on what is obstructing the truck swing motion.
As posted on the other topic, the best suggestion that does not involve hacking up nice passenger cars is to sell them and replace them with the Con-Cor short passenger cars that have lights. Some of them are really nice looking, and they are relatively cheap.
Or take the expensive plunge like I have done and redesign the layout--which could be both impractical and very costly. I redesigned parts of my layout to 36" radius curves, and retained a couple 26" radius curves that have larger radius "easements" into them, that work well. Now I'd be fine with a point to point layout too, but that may not work for most people.
Most other solutions to the problem of running full length passenger cars on tight radius curves will in the end prove to be unsatisfactory and/or very unsightly, and it is not worth destroying or hacking up some really nice passenger cars. Been there and done that...
John
Why not used edit the title of your original topic rather than start a 2nd one for the same purpose.
As BMMCNYNC commented: "According to the MTH website they are designed for 22" radius curves."
So as long as you relay your track to have 22 inch curves, the cars should work per MTH recommendations. As another commented, those are nice expensive detailed cars so it would be a shame to hack them up for 18 inch curves. It would be much better to preserve the cars and relay all 22 inch curves.
If the layout is only a 4x8, it should not be expensive at all to relay the track.
Rivarossi made a number of small compromises to get their cars to negotiate the tight 18" radius curves. Their trucks are of "narrower" section so less likely to interfere with other underbody details, etc. The kind of "scale" trucks under MTH cars will be slightly less forgiving of underbody obstructions.
Also, the Rivarossi cars don't have "scale" stepwells at the ends, either, to interfere with swing motion...
Threads merged.
--Steven Otte, Model Railroader senior associate editorsotte@kalmbach.com
riogrande5761An alternative is if the OP can rebuild with a slightly wider layout, he could fit 22 inch inner and 24 1/2 inch outer and the passenger cars could run on both tracks.
I agree. A simple 1' x 8' board attached to one side of the 4x8 would give the needed room to enlarge the curves. Maybe a 6" x 8' board would work?
I sure wouldn't hack on those beautiful passenger cars.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
what if we use freight trucks to replace long trucks for passenger cars? would that help to negociate tight curves?
john in georgetown Does anyone know of a way I can modify my new MTH PRR heavy weight passenger cars so that they will negotiate my mix of 18 and 20" radius curves. I was still new in the hobby when I purchased the 5 car set and did not realize they were for 22" radius. They were never run and until I push tested one through a tunnel to check clearance did I realize there was a drag as it was negotiating the 18" radius portion of the track. I really like these and I hope someone can offer a suggstion for a fix. Thanks so much---John [edited by admin to fix radius in subjectline]
I don't know that much about the MTH HW cars...but I'm assuming they are six wheel trucks. If that is the case and You can take the trucks apart, remove the center wheel axle on one and see how it works that way. If it does work, which I'm inclined to believe it will.....You can file down the wheel flange on them or replace the center wheel axle with a cheaper one that has the wheel flanges filed down.
I had a similar problem with Athearn HW Passenger cars back in the late 50's that had problem's on 18'' curves and the infamous Atlas snap-switches. I filed down the flanges on the center wheel axle and eveything worked out fine. Most all six wheel trucks have problems with negotiating sharp curves, not just passenger cars.
Good Luck!
Frank
The Athearn heavyweight RPO, Baggage, and Coach cars are full-length models of cars that were less than 80' long - IIRC, 63', 67' and 70' respectively. Their Diner, Sleeper, and Observation cars are based on 80' cars shortened to 70' (or 72'?) - although several railroads did have 70' observeration cars that were used as business cars. They are (at least loosely) based on ATSF cars; Irv Athearn was in the L.A. area.