De-railed

Discussion in 'Modelling, Memorabilia & Publications' started by bogieman, 11 May 2015.

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  1. bogieman

    bogieman Member

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    Hi,I've just joined"Rail uk"and I could with a little help.
    I have built an A2 peppercorn, and it runs well on the Straight, BUT when it takes a curve it de-rails.
    Can anyone shine a light on this? -Thanks Rob:roll:
     
  2. SpacePhoenix

    SpacePhoenix Established Member

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    What radius curves is it derailing on? Chances are that it can't handle 1st radius and maybe possibly 2nd radius?
     
  3. bogieman

    bogieman Member

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    Hi---I honestly don't know what 1st/2nd curve is, I borrowed 2m straight, and a couple of curves from a friend it was only just to make sure it was(engine) was working,the curve measures about 400mm-Rob

    By the way this is "O" gauge.
     
    Last edited: 11 May 2015
  4. Kristofferson

    Kristofferson Established Member

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    Make sure the train is properly railed and the track is joined together correctly - lifted fishplates or large gaps between sections will derail a train.
     
  5. bogieman

    bogieman Member

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    Everything is flat and rails ok!
     
  6. SpacePhoenix

    SpacePhoenix Established Member

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    Do the curves have any identifying markings (that look like product numbers)?
     
  7. bogieman

    bogieman Member

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    Yes--Peco set track ST-725 that's all that's on it-Rob
     
  8. SpacePhoenix

    SpacePhoenix Established Member

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    Try making the curve all 3rd radius or have a "transition" curve of 3rd radius at each end where the curve meets up with the straight section
     
  9. Kristofferson

    Kristofferson Established Member

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    Can you provide a video at all? No train should derail on tight curves if all is well with the loco and track.
     
  10. bogieman

    bogieman Member

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    Hi all-Iv'e just found out it's a 2nd radius curve-Rob
    --- old post above --- --- new post below ---
    On a 4-6-2, should the centre drive wheel be "Floating" to help take a 2nd radious curve?-Rob:roll:
     
  11. Kristofferson

    Kristofferson Established Member

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    No. if it's floating, it's not correctly railed. Hornby steam locos can take the tightest curves at high speed if railed correctly.
     
  12. sprinterguy

    sprinterguy Established Member

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    I believe that "floating" in this instance is referring to a centre pair of driving wheels that allows for lateral movement within the frames. The other option would be to have a flangeless pair of centre drivers.

    I'm only familiar with 00 gauge modelling, rather than 0, but it doesn't seem like either of these is a common feature on the ready to run six-coupled models (notably LNER Pacifics) available from Hornby or Bachmann which, as you say, can handle pretty much all set track curves.

    The radius of an 0 gauge second radius curve doesn't seem restrictive in relation to its' 00 gauge equivalent, so I wouldn't have thought that it would prove a problem having all driving wheels flanged,: Looking at kit built 0 gauge A2s they appear to have fully flanged driving wheels: However that's not to say that either of the options outlined above wouldn't allow for that extra level of movement required to negotiate these curves.

    Alternatively, bogieman, is there sufficient lateral (side to side, just to be clear to all) movement available in the leading bogie? There isn't any stiffness there in turning to left or right to a sufficient degree, and the bogie - wheelsets or bogie frame - isn't fouling any aspects of the main frame, or the cylinders, on corners at all? This can have quite a marked effect on running qualities on the real railways, as much as on our small ones!
     
    Last edited: 15 May 2015
  13. bogieman

    bogieman Member

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    Thanks for the info,I think maybe some fouling on the main frame might be the problem, I am in the process of springing the bogie and will let you know how that works---thanks--Rob
     
  14. ilkestonian

    ilkestonian Member

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    I'm no expert on model railways, but I think it would help if you could say which wheels derail first.

    Is it the bogie, or the drivers, and if the latter, which axle?

    The answer to this will surely help determine the best option to cure it. Eg if it's the drivers which derail it could be that a degree of centre axle float (side play as described above) is enough, or perhaps the coupling rods don't have enough freedom to allow any sideways movement of the axles. Or maybe a slight reduction in the depth of the flanges on the centre drivers will help.

    If it's the bogie, perhaps it's range of movement is insufficient, or maybe there is springing to centre the bogie and it's too strong.

    And don't overlook the trailing axle. Maybe it's not got enough side to side movement which could effectively increase the length of fixed wheelbase causing the drivers to derail.

    Just a few thoughts...
     
  15. bogieman

    bogieman Member

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    Starting from scratch again,am going to take off bogie and pony trucks and work from there.
    --- old post above --- --- new post below ---
    Thanks-(ilkestonian) 0-6-0 first/0-6-2/4-6-2 see what happens in that sequence.
    --- old post above --- --- new post below ---
    I have taken my 4-6-2,down to 0-6-0,it ran fine even on a S bend back and forward,I then changed the trailing radial truck to a pivoting one which had more movement,alas the wheels are rubbing on the inside of the frame,which de-railed the front end again on the curve.
    Tomorrow I'll phone David Andrews and try and find a solution.-Rob
     
  16. bogieman

    bogieman Member

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    many thanks for all your advice, I found out that 4-6-2 does not do, 2nd radius,it has to be "flexi track"-problem solved after an un-necessary strip down to bare frames----Thanks again--Rob.:oops:
     
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