Tighest radius

Discussion in 'N / Z Scale Model Trains' started by joefryfry, Nov 29, 2008.

  1. joefryfry

    joefryfry joefryfry

    I moved into a new house and no longer have room for a practical HO layout, so I was considering building a tabletop n-scale deal. What's the tighest radius you have been able to run an engine? I figure to probably be using a 4 axle diesel.

    How about the tightest radius for a steam 2-8-8-2 type?

    I realize there are many factors if you want to get technical. I'm just looking for a rough estimate. Thanks.
  2. pgandw

    pgandw Active Member

    According to the NMRA, 11" radius is considered a sharp curve in N (equivalent to 18" in HO). At one time, 9.75" was considered the sharpest practical curve. But as car and locomotive lengths have increased, and more realism has been demanded, minimum radii have been creeping up (just like HO, where 18" doesn't run everything anymore, and 15" is rarely a minimum radius). If you do stay with 4 axle diesel and 50ft or shorter cars, 9.75" will still work pretty well.

    It's really a matter of what equipment you insist on running. A 2ft x 4ft layout with 9.75" radius will work, but equipment, train length, and scenic opportunities will be limited - just like an HO 4x8 with 18" radius. Of course things look much better if you can spread out into a slightly large space. A hollow core door layout is a good small N layout - measuring at 30" or 36" by 80" long.

    my thoughts, your choices
  3. railohio

    railohio Active Member

    I wouldn't run it on anything smaller than 36" curves as it will look much better on the larger curves. That is why I've chosen to stick with purely diesel-powered layouts, very few modelers have the space to do justice to steam era operations.
  4. brakie

    brakie Active Member

    Actually I will recomand using nothing less then 121/2" curves and 15" being the better of the 2 in C55 curve track for small layouts.

    As far as C80 track...Nothing less then 11" and 19" being the better choice of the ready made curves again for small layouts.

    If you use flex track for your curves then like HO use the largest curve your space allows.

    A word of caution.. N Scale is not as forgiving as HO when it comes to track work..Make sure your track work is smooth.
  5. Boilerman

    Boilerman Member

    Smooth Track Work

    I have found that the trick to smooth track is to take your time laying the track and to sand the cork roadbed with 80 grit on a block, (this will eliminate any humps or bumps) before gluing down the track. :thumb:
  6. joefryfry

    joefryfry joefryfry

    My HO trains ran really well. I had a really nice layout going before I sold the house. I think I am going to build a small scenic layout with a train that chases itself, as this is all I have time, money, and space for. I'm more into the modeling than the operations. Thanks for your thoughts.
  7. Herc Driver

    Herc Driver Active Member

    I don't know how much experience you have with the various Nscale engine manufacturers (you probably have a lot and know the following information already)...but I've found that each manufacturer performs differently on the tight curves. Due to space requirements, I can only use 9.75" as well and I've found that any Kato diesel including the 90MACs take the turns with no problems unless you hook MU diesels - then it's better to use a longer coupler shank on the lead engine (it's provided with each engine, therefore nothing extra to buy). Longer Atlas engines like SD60s and the like also have no problems. InterMountain's SD45s growl around the curves but take them fine. LifeLike Proto N and "regular" series engines work great - but most of the LifeLike diesels are the smaller 4-axle designs anyway. Athearn's long SD70 units run fine with no problems. Bachmann's longest engine, the Dash-9, growl taking the curves as well but don't have a problem - and the lone steam engine I run, the J-Class 4-8-4, takes the curves fine but not great. I know the overhang of the longer frame diesels is terribly unrealistic but on my layout that can't be helped...there's only 22.5" available to turn the trains around on my simple dog-bone layout. I laid flex track for the curves at first, but had more derailments than curved snap track, so I switched back to snap track for the curves and flex track for the straight-aways. That probably means I didn't keep the radius constant, so I fault my track laying abilities - not the trains. When I went back to using straight flex and snap track curves, I put a gentle curve in the end of the final flex track section to lead into the curves. This allows the longer passenger train consists a little less stress on the couplers before they hit the tight 9.75" curves. And on that thought...Kato passenger cars almost never uncouple on the curves but Con Cor cars frequently do with their "fixed" knuckle coupler. Bachmann passenger cars have rapido couplers and they stay coupled in all cases. Finally, track code, car weight, and wheel flange size certainly make a difference too. I have a few cars that are too light and will ride off the tracks when pulled between longer and heavier cars on the curves. (Adding weight to them is on my long list of things to do.) Hope this info helps.
  8. joefryfry

    joefryfry joefryfry

    i was in the hobby shop yesterday and looked at some N track. It seems the 55 leaves little room for error, but the other stuff they had the rails seemed pretty unrealistic. i was using code 83 on HO, but probably wouldn't go for that "look" with N.
  9. Herc Driver

    Herc Driver Active Member

    I agree with you. I ended up with basic code 80. Anything outside of a foot away, and my eyes just can't tell the difference to warrent the time and expense of getting a more realistic code. I sort of went for ease and consistance on my layout. I can always get the Atlas code 80 snap track, and the Peco turnouts never seem to fail. Plus, I am only using manual throws on all my turnouts and I love the positive "lock" that the Peco's have.
  10. brakie

    brakie Active Member

    By the time the 80 rail is painted it doesn't look to bad.

    Like HO Atlas and Kato locomotives are at the top of the heap.
  11. umtrr-author

    umtrr-author Member

    My layout uses 19 inch minimum radius nearly everywhere on visible track and 11 inch radius in hidden sections. I run mostly diesels and don't expect to own anything larger in steam than a Bachmann Mountain I have on order.

    I would go for at least 19 inch radius for the 2-8-8-2 but then you're almost at HO size for your layout.
  12. TrainNut

    TrainNut Ditat Deus

    I've done three small tables.
    The first one used the smallest radius - 6-13/16". This is about the absolute smallest you can go for a four axle diesel or trolley.


    The next one is a circular table that uses 8" radius.


    The third table also used 8" radius.


    If your interested in more info for each, follow the link in my signature. Each coffee table has its own thread.
  13. joefryfry

    joefryfry joefryfry

    These are about what I had in mind, but I do have a kid on the way, so glass is a concern. I was thinking of doing something about those size, but portable, on wood. Thanks for all the suggestions. By the way, i quoted the wrong steam engine size. I'm not all that familiar with steam, but was thinking about the 2-8-2 or 2-6-2 or 4-6-2 or 2-6-4 or whatever is out there. Something that would navigate a turn of 12 inches or less. I realize this opens a whole new can of beans.......
  14. TrainNut

    TrainNut Ditat Deus

    Our first child was the reason I started building these small tables. As a stay at home dad, I could not very well spend hours upon hours out in the garage anymore with a new baby in the house. In place of glass, I cut a piece of plexi glass to fit the opening instead. Then after he passed the age of banging hard toys on the plexi glass, I put the glass back in. I think he was about two in this picture...
  15. Herc Driver

    Herc Driver Active Member

    That was a very smart idea TrainNut using plexiglass like that. Nice layout too!
  16. TrainGuyRom

    TrainGuyRom Member

    I have heard if you are starting in N, try a 2'x4' Layout. That is just wide enough for a complete loop (With 11"R Curves) I can run all of my N scale trains on 11" except for oe engine. So give it a try. Bachmann has some amazing prices on N scale. If yu want N scale steam go Bachmann!

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