Acceptable rail height difference?

nlaempire May 25, 2012

  1. nlaempire

    nlaempire TrainBoard Supporter

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    I just purchased a digital caliper and discovered the following about my random track purchases:

    Overall height for ties + rail in mm (code 55):

    Peco double slip: 3.25mm
    Atlas crossing/turnout: 2.55mm
    ME turnout: 2.80mm
    ME flex (wood): 2.75mm
    ME flex (conc): 3.05mm

    The measurements were taken diagonally, spanning at least 3 ties, and measured in 5 different spots, with an error of +/- .03mm, rounding to the nearest .05mm. When placing ends of ME wood to ME concrete, I can run my finger over the joint and shave a tiny mark in my skin.

    My question is:

    What is an "acceptable" difference in rail height variation? I'm thinking about purchasing plastic shims to place under the roadbed (or over the roadbed in cetain areas) to get the height differences to within .1mm. How do you all reconcile the differences?

    Tie spacing reference: 4 Peco = 5 ME(wood) = 6 Atlas

    I wish ME made more than #6 turnouts. That would save some headache and give a little uniformity to my layout (that is still in the planning phase)
     
  2. John Moore

    John Moore TrainBoard Supporter

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    No heigth variation accepted on the mains and branches everything to be leveled at time of track laying with shims if needed, or sanding down the cork roadbed. Probably one of the bigger causes of pilot truck derailment on some of the steamers with lightly sprung pilots is differences in rail heigth at the joint, not to mention rolling stock with the shallower flange profiles. Now on stub end sidings and yard tracks not too much of an issue with the lower speeds but if the cars are observed bouncing up at the rail joints then it needs to be leveled since too much vertical play can lead to uncoupling and derailments.

    Having been the route of mixed manufacturers with everything from Trix, AHM, Rapido, and etc. not again on the new layout plans. Main will all be Atlas and only the area up on the branchlines will have Peco switches with Peco track.
     
  3. nlaempire

    nlaempire TrainBoard Supporter

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    Thanks, John. I was really considering using foam roadbed, but now that I may need to shave the bed some, cork seems the way to go. Why did you choose Peco switches and track for the branchline?
     
  4. BoxcabE50

    BoxcabE50 HOn30 & N Scales Staff Member TrainBoard Supporter

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    Do everything humanly possible to eliminate any rail height differences. Shims, manipulating rail joiners, roadbed. Whatever idea is necessary. Otherwise you stand a good possibility of encountering troubles.
     
  5. John Moore

    John Moore TrainBoard Supporter

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    Also to add you can purchase .010 to .040 thickness styrene sheets which allow you to cut to fit under the roadbed to raise a section or go to a good craft store and thin sheet wood can be purchased to make shims. Folks in the model plane and boat end of the business also stock the thin veneer type woods.

    I have quite few Peco swithes because they are one of the few to make some short wye switches plus thier short radius turnouts that take about half the space of a Atlas turnout. Motive power is not an issue on navigating the tight turnouts since the biggest power on the branches is a 2-8-2T and a 2-6-6-0 that is to be used on the branch mains. The other power is that will do the switching is 6 wheel steamers, Shays, and some Class A Climax types plus a couple of 44 tonners and assortment of smaller critters.
     
  6. SteamDonkey74

    SteamDonkey74 TrainBoard Supporter

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    Yes, just get the railheads at the same level and you should be fine. Sometimes you take the deeper rail section, put a joiner on it, and then smash the other half of the joiner flat and put the shallower track on top of it. It'll take some experimentation and fiddling for you to find whatever is right for your situation.
     
  7. brakie

    brakie TrainBoard Member

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    Guys,If there is one important lesson I have learned over the years is to use one brand of track in order to save problems.
     
  8. SteamDonkey74

    SteamDonkey74 TrainBoard Supporter

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    You can use one brand of track, but you can also just get the rail-heads the same height. This is what we do in various modular groups in which I am involved. The main issue is not having a bunch of variations in the heights of the rail-head at the joiners. It'll create havoc with derailments, with unplanned uncouplings, with possible damage to pilots and couplers, and other issues I may have missed.
     
  9. BoxcabE50

    BoxcabE50 HOn30 & N Scales Staff Member TrainBoard Supporter

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    In the past I have used Peco switches and Atlas c80 flex. Having a stock left over from NTrak days, etc, am still using up that supply. They do not match for rail height, as Peco ties are a little taller, but adjusting for that is easy enough.
     
  10. Metro Red Line

    Metro Red Line TrainBoard Member

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    I have never noticed the difference in tie height between Atlas turnouts and ME wooden flex track. I do notice a considerable difference between the ME concrete tie flex and the Atlas turnouts. I usually make a "cutout" base out of .020" styrene sheet between the roadbed and the ties (or use .020" styrene strips under the ties) and that evens things out.
     
  11. CSXDixieLine

    CSXDixieLine Passed Away January 27, 2013 In Memoriam

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    I have had to shim Atlas code 55 turnouts to both concrete and wood ME code 55 track. I used strips of .020" thick styrene:

    [​IMG]

    I am sure there is a reason I did not shim the turnout under the points, I just can't remember why. Jamie
     
  12. NtheBasement

    NtheBasement TrainBoard Member

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    I decided on Peco turnouts and ME code 55 flex track. I wouldn't recommend it; this required dremel work on the underside of the Peco rail ends and shimming under the ME rail to even things up.

    First get the tops the rails even by hook or by crook. Solder them and use layers of paper to shim under the ties. You can sort of ramp it up by using paper of different lengths for the layers. Use lots of Elmers between the paper and glue them to the cork. Then position the already soldered track over it and lay something heavy and flat on the track while the glue dries. Short pieces of steel bar stock work great, but a metal rule or styrene sheet with a book on top works fine. You can get perfect results this way because the Elmers will squeeze out from between the paper layers as needed to make the road bed exactly right.
     
  13. Arctic Train

    Arctic Train TrainBoard Member

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    Ditto what Larry says. Mixing rail manufacturers can be done but I guess it'd take lots of patience and precision. If I was understanding your first post (re. the difference in rail heights) I was amazed at the differences within the ME product line. Love the look but makes me glad I didn't go that route. I make enough of my own headaches without the added pain from manufacturing inconsistancies.

    I'm a Peco guy and found switching from code 80 to 55 was a no brainer. Smooth and no problems. The only issues with top of rail height I've had is at my swing out gate. Blame that on carpentry skills (sigh). To cure that incongruity, a few swipes with a file on the rail head joint and the difference was gone.

    Brian
     
  14. randgust

    randgust TrainBoard Member

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    I'll do whatever I have to do to get the heights smooth at the head surface. You can shim to get the track supported under the ties, but if the rail head heights don't agree at the joiner (and even various brands of C80 don't) that's what a short straightedge, a Dremel, and jewelers files are for. Start filing. It's OK.

    If you're mismatching railhead heights that's also a good spot for a soldered joint rather than try to bend up a joiner to fix it from the bottom and hold it as well. Just file the top surfaces smooth with a nice vertical transition. Get some 600 or 1000 grit automotive-grade sandpaper to finish it off smooth. Even back in the 70's I used to travel to friends layouts with my Dremel, tiny bubble levels, steel rulers, shims, and needle files and clean up track messes.
     

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