Maximum radius

Discussion in 'N / Z Scale Model Trains' started by Dave R., Jul 17, 2007.

  1. Dave R.

    Dave R. Member

    I've been through the files 'cause I don't want to bother y'all with the same old questions but I just didn't find an answer.
    What is the maximum possible radius I need to worry about and why.
    I want to do the "Orange Blossom Special" and I thought I read somewhere that the F7's take an inordenint amount of radius, is that right?
    BTW, who makes the best F7?
  2. tillsbury

    tillsbury Member

    Hey, I've got yard tracks with an infinite radius... :)

    Don't know what you mean by 'maximum radius'... you just make it as big as you possibly can. The bigger the better. Your only issue will be with minimum radius -- make it at least 12-13" and preferably 15" or more. In places where you will want photos and the train to look 'right' you'll want 18" or more...

  3. Triplex

    Triplex Active Member

    Maybe he's asking "What's the largest minimum radius I could have reason to need?"

    F7s in any scale will usually take the standard "sharp" curve (18" in HO, 9.75" in N, etc.) and often sharper. It's the passenger cars that you need to be concerned about. In that case, the advice given above (preferably 15", with 18" if it has to look realistic) is good.
  4. Dave R.

    Dave R. Member

    Yesterday, when I asked my six year old grandson Ben, how fast he was running our new Atlas Shay (he was braking it in) he replied, "40 per cent of available power".
    Today I moved the refrigerator out of the area where we are building our lay-out. We now have an eight by eighteen foot space to build in.
    I'll put 42X42" benchs at either end of the horse-shoe lay-out and thin the long middle section down to 30" so we have room to move.
    You're right, Triplex, it's the heavy-duty Pullman cars that would be the problem.
    I've put a mottled green on desert yellow paint scheme a 1/144 Bf 109-E/trop; I can't wait to try to put a lime green on yellow paint job on a a pair of F7's (and a F7b) with emerald green cars, on an "N" "Orange Blossom Special".
    Thanks so much Guys,
  5. umtrr-author

    umtrr-author Member

    I like and have been using almost all 19 inch radius on the visible sections of my layout: yes, sectional track, yes, Code 80, yes, it pre-dates the introduction of Atlas Code 55... yes, I'm ducking...

    There are a couple of places where I must cheat and use a smaller radius turn (I'll never tell where!) and my full length passenger cars don't have difficulty, although they don't look as good.

    I use 11 inch radius in the staging areas and hidden track with no worries.
  6. SD90

    SD90 Active Member

    On my last layout, I had 33" radius everywhere that was visible, and even a 40" radius on a couple of spots. The tigtest hidden was 23", in the lower spiral tunnel. It was even on a 2.2% grade.
  7. Dave R.

    Dave R. Member

    40" radius? That would take an 80"+ wide bench? That would be nice but I just don't have that kind of room. I've decided to go with 48"sq.s at either end of my 18ft room as turn-arounds with 23" radius' and a 16" bench connecting the two. It's K.I.S.S. for me, for now.
  8. TrainJunkee

    TrainJunkee Member

    That will put the edge of the track 1 inch from the edge of the table... If you delrail a train it may nose dive to the floor. You might want to go with 21 or 22 radius or buils a lip to keep them on the table
  9. Dave R.

    Dave R. Member

    Oh! Good point! Does anyone ever "bank" their track? Don't prototype tracks have banks?
  10. 60103

    60103 Pooh Bah

    The railroads call it "superelevation". It's a tricky topic. Having a little bit makes the tracks look better; not sure if it actually has any effect. On the prototype, the amount is determined by the radius of the curve and the speed of the train but you get interesting effects when train speed is not at the design level; I've been in a train stopped on a superelevated curve and you feel that you're going to slide off onto the inside.
    Superelevation must begin gradually (no 6" jump where the curve starts) and the real railroads use transition curves where the radius gradually increases.
  11. umtrr-author

    umtrr-author Member

    I did superelevate one curve just for the effect. I glued .010 inch square Evergreen styrene to the outside of the track (19 inch sectional, Atlas Code 80) before laying it. It's not really necessary but I liked it!
  12. MasonJar

    MasonJar It's not rocket surgery

    In an 8' x 18" space, you would be better off going "around the walls", assuming you can live with a duckunder of lift/swing gate. With shelves 12" to 24" deep, you'll have an interior "pit" of 4' to 6' wide. You can also run big curves at each end (theoretically up to about 46" radius across your 8' ends).

  13. Dave R.

    Dave R. Member

    How hard would it be to build a "lift gate"? I'm a retired cabinet maker, so I've got those skills and tools but that little "N" track worries me. Are there any "tricks" I should know?
  14. MasonJar

    MasonJar It's not rocket surgery

    I have not built one, but as a cabinet maker, I would say it's probably not too much of a problem for you!

    I understand the keys to be:

    - make sure it does not sag
    - make sure it closes exactly the same every time
    - wire it so trains cannot run near it (or at all) while it's open

    There's been some discussion here in the past - you might try a search to see what tips and tricks turn up in those conversations.

  15. 60103

    60103 Pooh Bah

    Try to anchor the lift gate's supports as close as possible to the gate. Even if you eliminate expansion on the gate, the rest of the benchwork loves to shift. And one old member said, after you eliminate all expansion/contraction in the benchwork, you find that the room changes size.
  16. woodone

    woodone Member

    Any type of lift gat will give you fits.
    The only material that will not shift is steel, then it expands and contract with heat or cold.
    I would try to find a differant plan for the room.
    Read some MMR back issues- (Layouts) some will have lift gates- no one ever has nice things to say about them. They rank right up there with duck unders.
  17. Dave R.

    Dave R. Member

    The only practical building material I can think of is 2 or 4inch Styrofoam. I'm re-insulating and drywalling my "train room" so I'll have some time to think about it. If I do a lift gate I'll start a thread on it. I need to figure out how to post pictures. Thanks for all the advise, guys!
  18. Jim Krause

    Jim Krause Active Member

    Model Railroader and Railroad Model Craftsman magazines have run several articles on various types of gates/bridges etc over the past year. Try July 2007 RMC, page 69 as a start

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