Ok, what's the big idea here?

Discussion in 'HO Scale Model Trains' started by CNWman, Apr 2, 2007.

  1. CNWman

    CNWman CNW Fan

    I don't believe this! I finally get my IMRC cylindrical hopper all done up in CNW green and such and looks great, and what do I discover? The :curse: thing won't negotiate 18' curves! I tracked the problem down to the fact the trucks are able to negotiate it on their axels, it's just that they keep on hitting the underside detail and I can't figure out how to make the trucks not hit the things yet make the turn! worse still, the car is so stuborn, it won't go through certain parts of the layout, yet on another part of the track recreating the same place, the car just acts like it's not the same! It looks cool and all, but aparently I just wasted 30 bucks on a car that won't take an 18' turn! :mad:
  2. 2slim

    2slim Member

    This is one of those 'lesson learned' dudes you hear people talking about. It's been my experience that the more underside detail a car has the less it will negotiate smaller radius curves, because like you said, "the trucks keep hitting things". You will probably get told that 18" radius is too sharp for the car, (and it is, I believe I read a review in MR which stated 22" was the minimum for this car) so I guess you have a choice of whacking off any details that are interfereing with the trucks or getting rid of the car. Depends on which details the trucks are hitting, maybe you could take a file or a sanding stick and remove only whats in the way, might not be too noticable with some weathering. Good luck!
  3. N Gauger

    N Gauger 1:20.3 Train Addict

    Yup!! That's exactly what i did with my stubborn cars.... File off anywhere that's hitting .... I have done this to about 10 HO and N gauge cars and no one ever noticed anything... :)
  4. CNWman

    CNWman CNW Fan

    Thanks for the tips:thumb: I've just been eager about the car since I got it, so you could probably say I was really ticked off when I learned that the :curse: thing wouldn't negotiate my turns. Maybe it's because the thing is longer than my other rolling stock, but then that doesn't exlain why it will go only on some curves with some resistance and just de-rail on others. I'm also angry with the fact that the site didn't say the :curse: thing couldn't handle past a minimum curve. My outburst above was for venting because I was so angry and I didn't want to crush the car. Then there's that underside cable detail that goes right above the trucks. When I hold the car upside down and spin the offending axel (inside axel, both trucks), it always resists a little. My Pk1/2's do better than that!

    Here's the problematic car (it's just like my tank car, only this time there's no hill): http://www.discountrails.com/servlet/the-6465/HO-InterMountain-Cylindrical-Covered/Detail
  5. CRed

    CRed Member

    Nice car you have there bud,I wouldn't mind one of those for myself:thumb:.I just bought a bunch of high end NP Covered Hoppers and hopefully I'll not have any problems,but I'll be using atleast 26" radius curves so I should be O.K.Good luck with your problem.

  6. CNWman

    CNWman CNW Fan

    Long story short

    It's working.:eek: The car is somehow fixed. I just ran my F3 with the problem car hooked up to it and my grey hopper on it's other coupler and ran the two car train around the track on both sidings. The thing is acting beautifly now!:D Me:0 InterMoutain:1:D:thumb:
  7. Russ Bellinis

    Russ Bellinis Active Member

    Sometimes when a car barely works on a tight radius, the amount of overhang on the locomotive trying to pull it will make a big difference. A car that will work behind a f3 or gp7 will have problems if hooked to a dash8-40c.
  8. CNWman

    CNWman CNW Fan

    What do you mean by 'overhang'? Remember, I'm still somewhat of a newbie in MRR:oops: :rolleyes: :D
  9. Squidbait

    Squidbait Recovering ALCO-holic

    Check how your trucks are mounted too. You should have one loose, so that it turns but also rocks from side to side a bit, and the other should be tight enough to turn freely but not rock.

    Sometimes if the trackwork is a bit uneven and neither truck can rock, it can derail the car.
  10. CRed

    CRed Member

    If you look at your engines going around the curves you'll notice that the end of the engine will hang over the track,the larger the engine the more pronounced it will be.So while a smaller engine may have little problem the larger ones will and end up pulling the cars off the track because their rear end swings out so much over the edge of the track on tighter curves.I hope you can understand what I said as I'm no expert either:oops:.

  11. Gil Finn

    Gil Finn Active Member

    I have cut up more than a few steps and the like.

    The less detail the better I like the car. I mean for the most part you cant see any of it anyway.
  12. Ralph

    Ralph Remember...it's for fun!

    Count me among the trimmers and filers. I had to cut off a little section of the front of an Athearn SD9 that just wouldn't clear a few sections of my layout. Only the rivet counters and true EMD fans would notice. (I don't invite them over) :)
  13. pgandw

    pgandw Active Member

    Measure the car length in inches (this works for any scale). Multiply the result by 3. That is your new minimum radius (and I'll bet it's not 18").

    The more we demand highly detailed rolling stock, and the more manufacturers deliver, the more we will be confronted with having to use the "3X" rule-of-thumb for minimum radius.

    North American railroads, in order to be profitable, must continually work at improving efficiency. Since the beginning of North American railroading, locomotives and cars have continually increased in size. On the prototype, many tunnels, bridges, and curves have had to be rebuilt at enormous cost because they couldn't handle the ever-growing size of rolling stock. Yet the costs in improvement to the right-of-way are quickly repaid by running longer trains with bigger cars.

    In HO, 18" was a fairly successful minimum radius for freight cars and smaller steam engines in the 1950s. The cars weren't as detailed, and couplers were crude and over-scale. Even then, full-scale passenger cars couldn't go around 18" radius curves, so manufacturers made "shorty" passenger cars that were a scale 60-70 ft instead of the full 80ft. The "shorty" passenger cars could do 18" radius curves.

    50 years later and 60-90 ft long cars are the norm on the prototype. Yet we still insist on using 18" radius curves that were marginal for some 1950s prototypes, and wonder why the things won't stay on the track.

    An interesting fact - a model of a modern 80ft car in N is just as long as a 40ft box car in HO.

    just some thoughts of mine
  14. jeffrey-wimberl

    jeffrey-wimberl Active Member

    How far the ends of a car hang out past a curve is called 'Bogie Throw', how far the middle of a car hangs over the curve is 'Overhang'.
  15. Torpedo

    Torpedo Member

    Interesting and useful information I've not heard before. When you refer to car length in this case, is the measurement made from end sill to end sill, or between coupler faces? Between end sills, I imagine.
  16. CRed

    CRed Member

    Me either,but it's not always practical for alot of people who have to get by with either the minmum or maybe a little over because of space.I have a BLI AC6000 which happens to be a very large engine and by that formula I would need 30" radius curves.fortunantly I am actually going to be able to do that,but alot of people wouldn't be able to.Still,it's a good barometer and people should try to get as close as possible to it to avoid problems with their cars and such.

  17. pgandw

    pgandw Active Member

    The radius rule of thumb comes from the Layout Design Special Interest Group (LDSIG). The article in question is here:
    Follow the link at the bottom to see my comments that the group added.

    The gist of my comments was that you can successfully use a smaller minimum radius, looks notwithstanding, provided you are willing to give up things like full underbody detailing, body-mounted couplers, and correct riding height of cars. And you should expect to have to test nearly everything because tolerances and clearances are going to vary from layout to layout and rolling stock piece to rolling stock piece.

    OTOH, if you have room for the 3X or larger radius curves, you are almost guaranteed no derailments from tight curves.

    yours in tracking
  18. PRRman

    PRRman Dum-Dum Pop Addict

    Yeah, that's an especially big problem with steam engines...CNWman, beware! I know you want either a Prairie or a Consolidation, but don't be surprised if the overhang creates any major problems:p!
  19. iis612

    iis612 Member

    I have run a consolidation on 18" ez track curves without any problem.
  20. Speaking of large steam and small corners, I've run my Big Boy over 15" radius (unbelievably slowly lol) and it made it! The thing's only rated for 16.5 (Old Rivarossi)! Perhaps it is a good thing that I removed the linkage arm between the two drive bogies...XD

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