9 3/4 Radius

pga7602 Feb 1, 2009

  1. pga7602

    pga7602 TrainBoard Member

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    Hey guys, I was going to start building my first layout right out of the Atlas Level 1 book.

    N Code 80 Layout Gallery

    I went ahead and bought everything I needed to complete the build. After reading through information on this forum and others, I am beginning to have buyer's remorse. The consensus seems to be that a 9 3/4" minimum radius curve is not a good idea. I'm hearing it should be 11" at the very lease.

    So do u think it's worth it for me to dump some of these curve parts and go with flex track and make it 13" radius minimum? How hard is it to expand this layout to use flex track and have a longer radius? Note: I am using a 36x80 hollow door for a base.

    Please advise. Thanks.
     
  2. firechief

    firechief TrainBoard Member

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    There are a couple of factors to look at.

    1- What size of locos and cars will you be running?
    -I have a lot of 9 3/4 inch curves on my layout. I run mainly 4- and 6-axle diesels with 60 foot or less freight cars. Some larger steam locos won't like the tight curves at all.

    2- How critical are you on looks?
    - I do have a couple of longer autoracks and passenger cars, as well as a U50 diesel. As long as there is enough clearance in areas where there are double tracks, they will pass. The problem with them is that they overhang on the shorter curves and don't look "real". If you can live with that, there's no problem.

    My layout is roughly equivalent to 3 doors in a U-shape. 2 sides of the U are actually doors. I have about 105 feet of mainline, a large yard/industrial area, a town, and a lot of hilly areas. If I didn't use 9 3/4 inch curves, most of it wouldn't be possible. I prefer smaller diesels and trains of about 10 cars max., and I'm not too worried about looks, so everything is good for me.

    Dave.

    PS. Welcome to the group.

    Dave.
     
    Last edited by a moderator: Feb 1, 2009
  3. Powersteamguy1790

    Powersteamguy1790 Permanently dispatched

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    pga:

    I would avoid 9 3/4 " minimum radii curves. This will severely limit the locomotives (two axle) and rolling stock you can run on your layout. If you want modern rolling stock or even 85' passenger cars, they won't look well on that curved radii.

    I would suggest using 12 3/8" as a minimum radius. Then all six axle diesels and most steam locomotives can negotiate that radius.

    If you want a nice sized layout, I would suggest using the hollow core door 80x36". This isn't too formidable and would allow you to have 13 7/8 minimum radii. It also will allow you to try some scenery. On top of the HCD put a 2 inch pink/blue foam base.
     
  4. pilotdude

    pilotdude TrainBoard Member

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    Since that layout is designed to fit into 27" x 50" space you certainly have room to expand it out on your hollow core door both in length and width and I think it would be worth it. I would echo Bob's recommendation of a minimum radius of 12 3/8" (that's the 315mm Kato Unitrack curve) for running any of the longer 6 axle locos. On your industrial spurs you could use tighter if you needed to. I am working on a 2' x4' layout and I do have some of the 9 3/4 radius curves in it out of necessity but I am only using small 4 axle locos like the RS2 and cars that are 40 foot in length or less.

    I don't think it would be hard at all to expand it with flex track. I have Peco Code 55 flex track I used in another layout and for radius I would use some Kato Unitrack to experiment with radius and when I got what I was looking for I would trace it out and use it as a guide for the curves. My way of skinning the cat...

    Welcome to the board!
     
  5. CarlH

    CarlH TrainBoard Member

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    I agree with the other comments that it is best to avoid using the 9 3/4" radius curves if it is possible, and to make your minimum curve radius be as large as your space will allow. The 9 3/4" radius curves will be particularly limiting, even when compared to 11" radius curves.

    If you cannot exchange the 9 3/4" curves for something larger, perhaps you could use some of them in a yard, on one particular "branch", or on some test track? If you use them, you want to isolate these sharper curves someplace so that most of your layout will still be usable by larger/longer rolling stock. There are many locomotives (i.e. 4 axle diesels) and rolling stock (i.e. conventional length freight cars) that can work just fine on 9 3/4" radius curves, as long as you use some curve transitions, don't use reverse curves, and don't use long trains.
     
  6. mtntrainman

    mtntrainman TrainBoard Supporter

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    I ultilize 5 - 36x80 HCD's for my layout. A 36x80 HCD with that layout configuartion (outside spurs) would give you approx. 12.5 and 11.25 radii on the end curves. I wouldnt go smaller. Use the flex track (C80 or C55)...it gives you more room to work with.

    Flextrack is just that...flexible...as your layout plan should be... :tb-wink:
    JMHO

    .
     
  7. Triplex

    Triplex TrainBoard Member

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    That layout is quite simple. Should be very easy to adapt to flextrack or any sectional track system, and to change curve and turnout sizes.
     
  8. pga7602

    pga7602 TrainBoard Member

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    Wow, thanks for all the help guys. As a total newbie to this hobby, your tips are most welcome. I'm hearing a lot of echoes as to what my setup is like. So please allow me to give more detail in what I'm planning:

    - 36x80 Hollow Door
    - 2 inch Dow blue extruded foam as base
    - Loco- Atlas EMD GP35 Phase 1A (4 Axel right?)
    - Currently- All Code 80 standard Atlas track

    What I'm hearing is to go ahead and change out the radii by using Flex track. Which brand of flex track do you recommend? I think I'm stuck with code 80 now, since all my turnouts have been bought. :( If I knew better, I should have went with code 80.

    Also, compare to the petco turnouts, my atlas turnouts don't look as prototypical. I guess I can just build the RR with what I have as far as turnouts and upgrade later.

    Thanks again,
     
    Last edited by a moderator: Feb 1, 2009
  9. mtntrainman

    mtntrainman TrainBoard Supporter

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    You say "...- Currently- All Code 80 standard Atlas track." but then say "...I think I'm stuck with code 55 now." I am confused...lol. If its all C80 sectional...use the C80 flextrack. C80 will allow you to run anthing including 'pizza cutter' wheels. I also find C80 is more forgiving when it comes to derails caused by 'beginners' track laying. My whole 5 HCD layout is done in C80. With ballasting it doesnt look to bad. C55 tie spacing is not proto either...the C80 is closer. Go with what ya have the most of...but most of all..have fun...thats what its all about.

    Dont sweat the petty stuff...and dont pet the sweaty stuff !...LOL


    .
     
  10. pga7602

    pga7602 TrainBoard Member

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    mtntrainman: Good catch, I went back and edited my original post. It's all code 80.


    All: So as far as door layouts go, what do you think of the N6 layout I posted? Is it a good one to start with?
     
  11. mtntrainman

    mtntrainman TrainBoard Supporter

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    I think as a starting place...it will work fine for you. The spurs could always be converted to mainlines to extend to a future expansion (additional doors). If I may...I might also suggest a 2 inch clear area or 'buffers' from the track to all outside edges of the HCD. This gives plenty of room for any ooooppppssss derailments. Trains will lay over on this 'buffer' edge and you wont watch in horror as your prize locos and rolling stock bounce off the floor in hundreds of pieces...JMO.

    :tb-wink::tb-cool:
    .
     
  12. Glenn Woodle

    Glenn Woodle TrainBoard Member

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    Having 2 spurs & an industrial area is a good place to start. One spur could be your link to the outside world. The other could be a yard area to service locos, etc. One side of the loop has the runaround track for switching. Looks like you can have a lot of fun building, operating & putting in some scenic details.
     
  13. Triplex

    Triplex TrainBoard Member

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    Yes, but note that you don't have to stick to power that small. With the 13" minimum you want, 6-axle diesels won't have a problem. I'd only worry about the biggest steam or something like a U50.
     
  14. brakie

    brakie TrainBoard Member

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    While the 9 3/4 will work I highly recommand going the next step and use 12 or 13" curves.

    As far as your chosen layout design..Not bad but,for your consideration.

    N Code 80 Layout Gallery

    The reverse loop can be wired by using a Atlas Controllor part number 0220

    https://secure.atlasrr.com/mmMOD1/Images/220.gif
     
  15. SleeperN06

    SleeperN06 TrainBoard Member

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    I was holding back from saying anything, but when I saw N06, well anyway.
    I bought the whole kit and realized right off that I needed to make changes. I wanted to be able to turn the trains around, so I added two reverse loops. My hollow core door changed. The biggest problem was the turnouts in the back. Of all the turnouts, those were the problem ones. I decided that I would never have turnout in the back. Also the 9 ¾ radius track was a big problem for my six wheel trucks and long passenger cars.
    I have a photo of the whole layout, but can’t find it. The rest are at Photobucket
    [​IMG]
    [​IMG]
     
  16. Powersteamguy1790

    Powersteamguy1790 Permanently dispatched

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    You can always use clear plexiglass on the edges one inch high to protect against derailed loco's or rolling stock from falling on the floor.
     
  17. Powersteamguy1790

    Powersteamguy1790 Permanently dispatched

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    pga:

    You're better off finding a layout that doesn't have 9 3/4 " radii for the obvious reasons mentioned above. You do have room on the HCD of 80x36" to make a very nice layout with suitable radii. You'll be happier in the long run.
     
  18. SleeperN06

    SleeperN06 TrainBoard Member

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    The problem is with that size of layout your stuck with an oval of a figure 8 to keep from using a 9 3/4.
     
  19. Powersteamguy1790

    Powersteamguy1790 Permanently dispatched

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    It's easy to find another layout that doesn't use 9 3/4 inch radii. The HCD pga has is big enough to accommodate larger radii. That isn't the only track plan available for a HCD layout.
     
  20. pga7602

    pga7602 TrainBoard Member

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    WOW!.....

    I just just finished glueing the foam, adding folding legs, and will start painting the door today. But now you guys are giving me second thoughts as to what layout to do on my door.....

    I am not experience enough to understand things like reverse loop. All I was going to do was changed the 9 3/4 and 11 radii to 13 and 15 radii and extend the main line. Ultimatley, what I want are 2 to 3 industries, a mountain tunnel and some realistic scenary. I really like David Vollmer's layout.. do you think that would work better?

    http://www.thevollmerfamily.com/Pennsy/Trackplan.html

    Sounds like I may have to go back to square one...
     

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