TBA II Progress thread

Discussion in 'N / Z Scale Model Trains' started by seanm, Feb 14, 2005.

  1. seanm

    seanm Member

    I am moving these posts over from the Layout Party 5 thread so all my posts will be in the same place. for those of you who have sen these before... sorry!

    Helix started!!

    Background: This is an N-Scale layout. It is two decks around the wall. Layout plans are posted all over the place so I won't post them here. I am building a helix to get between the two levels. The curves are going to be something like 19" radius... and there will be a 1 foot strait section on each side of a lap.. Grade works out to right at 2%. I think I will need about 6 laps.. maybe more. Inspiration for the design came from a model mag that recently published something similar. I believe I will be using the threaded rod sort of support system so I can tune the grade.

    Here is where the helix will be.... minus the dirty cloths!!


    I am using 1/2 ACX plywood ripped into 4" strips that will make up the helix. It will be an elongated hexagon shape... I guess that sort of make is a dexagon? I can get 6 pieces from each 4" wide strip. 12 strips per 4x8 sheet... so 72 pieces per sheet.

    The first one will be a template...


    The rise is about 19" between levels.. Here you can see the levels. The helix will be behind the background boards... where the pile of cloths are. :p


    I am not sure how fast I will post pictures of progress... but if you want to see the latest pics BEFORE I get them up here, plus any that don't make The Gauge cut, check out my web site here.
  2. seanm

    seanm Member

    All strips cut for Helix...

    Got all the strips of ply cut for my helix.

    I did come across something "funny" about plywood.....something I will look for in the future. At a lumber yard I purchased 1/2" ACX plywood. I later needed another two sheets and went to a "Yard Birds" and purchased 1/2" ACX plywood. From the lumberyard it was 4 ply. From the Yard Birds it was 5 ply! I like the 5 Ply better and it was a couple of bux less... Odd...:confused:

    Anyhow, here is a look at the stack of strips 4" wide ready to be cut int 16" long trapazoids with 22.5 degree angles on each end.

  3. seanm

    seanm Member

    Cut all the long pieces into short pieces yesterday. Used a nice miter saw I borrowed from my uncle. Made short work of the cutting and was very accurate.


    Now all I need is a buisquit jointer and some glue (and rods and ...and...and...

    This is the layout of the loops of the helix. Need about 8 of these. One as a base and then 7 actually for track.

  4. seanm

    seanm Member

    Todays progress...

    I took the bucket of parts and drilled holes and cut biscuit pockets in them and assembled all the loops.

    If I were to do it over, I would drill the holes last, but live and learn.

    If you have never seen a buscuit jointer it is a cool tool!


    It cuts a pocket in the edge of the wood....


    And you glue in a biscuit. Makes a very stable joint.


    Anyhow, if you assemble enough of these you get a big stack!!!


    The foil was to keep the layers from being glued together. The white pins are cut up plastic coat hangers used to "register" the holes so the stack will line up.

    That is it for today!! I am out of town for a couple of days now, so no more work till sunday!
  5. seanm

    seanm Member


    I have the first grade set. This should make things go a lot faster. I still have to add some track before I go up another level.

    The track looks like a double track helix, but the outside track is just skirts the helix to give the lower level a way to run constant with out entering the helix... you can just see the outside track depart at the back near the wall. There will also be a switch on the right side of this level. This will allow the exit coming down the helix in either direction on the bottom level. The top level will also get a similar treatment.

  6. seanm

    seanm Member

    Well, I am getting there with the helix. I have 2 more laps to go!! Then I have to fine tune things a bit. It is really fun to visualize something and then make it happen like you saw it in your head. Almost magical!

  7. seanm

    seanm Member

    Helix has hit the summit!! All I need to do now is some track filing here and there from the excess solder and attach feeders. Works well with a car or two going down hill... we shall see with an engine maybe this weekend!



  8. Tileguy

    Tileguy Member

    Sean, I'm really looking forward to seeing this helix develop.For my room size layout i am going to need one to run up to top level branch line and down to a main division point yard and additional staging area.
    Your experiance while building yours will be invaluable to me.Mine will also need to be elliptical rather than circular to minimize the grade.
    This is one more reason this mini layout is going to be interesting.It will give me an opportunity to see Just how tight i can make this radius for operation of differant equipment.It would be nice if i could get a Mike and an RS or GP7 to make a tight radius reliably.
    In a helix it doesnt need to look good doing it,it just needs to do it :D
  9. seanm

    seanm Member

    I don't think a tight radius is a problem in a helix, but the problem is when you tighten the radius you drastically shorten each loop and this increase the grade for a given vertical spacing. I went with just short of a 3 " spacing and that is just enough clearance for my hands to get under thre to pull out a derailed car in N-scale.
  10. Tileguy

    Tileguy Member

    What size elliptical footprint will this helix have??
    Mine will end up where my L shaped workbench resides at present.I would like to contain it in an area 20" x 54" if at all possible.What do you think??

    I just started thinking about this a couple weeks ago.
    I know building a helix is tricky and time consuming.
  11. seanm

    seanm Member

    I didn't measure it once it was complete, but from the plans I used to construct it it fits in an area 56" by 44". It could be a bit narrower but 20" wide is going to require 9 3/4 radius curves... That is pretty tight!
  12. Matthyro

    Matthyro Will always be re-membered

    I have only had one helix in my N gauge layout. It was 15inches in diameter which I thought was sufficient. I had problems with long trains where cars got pulled off toward the center. The only way I found to improve the situation was to increase car weights. This meant shorter trains or more locos. The real issue was when the cars in the middle of the train pulled off is that the trailing cars left on the track began going backwards and by the time they reached the bottom of the helix they were really travelling fast. The speed was such that they just flew off the track. Now I know that accidents can happen on any grade if a coupler lets go but there is no helix on my layout anymore. In looking back I realize a radius of 20inches would have solved my problem.
  13. Tileguy

    Tileguy Member

    Not as tight as the mini layout i'm building right now. ;)
    Actually i do have room for a 20" radius.perhaps even 22-24 but I would lose all of my workbench in the process.
    Well, i guess i could relocate it as a slide in slide out under the benchwork if i need to.

    Thanks Robin for sharing your tribulations with that smaller radius :)
  14. cidchase

    cidchase Active Member

    Wow, Sean, I think that helix is a nice job. I see a couple of things in this thread
    to ask about. The biscuit cutter joint is really slick!! Why not use it where the lap
    joints connect each loop?? That 1/2" on each level takes 3" away from you, plenty enough for another turn!! I've wondered about this on other helices
    I have seen . I wonder if the 1/2" thickness is a little overkill? I'm thinking that
    3/8" plywood would be plenty stiff in the short distances between supports. I also
    think that the lap joint could be made in the plywood subroadbed itself by routing
    out half the thickness of each piece and lapping it without impinging on the
    vertical clearance. Also thinking about using 2 pieces of masonite spline to lap the joint, but on the top, inside and outside the track loop. Anyway, the extra clearance would let you reduce the grade by adding a loop.

    Another question regards the stringlining with long trains. Why not super- elevate in the reverse direction?? A little negative banking would go a long way to keeping those wheels on track, I think. Like you say, the operation is more important than the appearance!!

    Just my thoughts... what size threaded rod did you use? The whole thing looks
    very neat and very stable!!
  15. Tileguy

    Tileguy Member

    Actually 1/4" baltic Birch underlayment would likely be fine considering the amount of supports in a helix.I wouldnt even consider 1/4" luan mahoginey but birch underlayment is pretty stable comparatively.
    3/8" Plywood if you can get it in a more than 3 ply panel would be good,but 3 ply panels are almost worthless in my experiance in the trades.Any plywood less than a BCX rating isnt worth buying IMHO either.
    CDX has become Junk,i wouldnt build a doghouse out of it.

    MDF is probobly as strong aand stable as it gets but is really subject to problems with moisture(although it has improved immensly over the last 6-8 years

    I have also considered using 1/8" hardboard laminated in a 3 ply layer.Testing of any of these methods will be done before i build mine,I dont ever want to build a second one if i dont have to.
  16. seanm

    seanm Member

    Cidchase... Good questions!

    I went with what I was going to be using on the rest of the layout and it was easliy available and I like STIFF. As for the one lap joint on each loop, I did that so I could work quicker. It really only looses me 1/2" and I 2 3/4" inches of clearance... really pleanty for n-scale.

    I would not want to have to experiment with the reverse elevation of the rails... so far it is really good. I have run some 20 and 30 car trains up and down as well as 12 car passenger trains with no problems.

    The rods are over kill as well. They are 1/4 inch. You can lift the entire helix by 1 corner. (grin)
  17. seanm

    seanm Member

    Have been making pretty steady progress on the layout. Not a lot to photograph though. I have the track for the main line, hidden staging and the interchange on the upper level in. No wiring yet, so no trains, but I am hopefull that in a couple of weeks I will have my first train through Summit Station.

    I have revised the track plan to reflect the sidings and likely industries. Here are the latest plans.....



    The rest of the construction pictures are HERE in no particular order.
  18. seanm

    seanm Member

    A while back I decided I wanted to make the control panel for the layout sort of modular. I asked some questions on the Layout Design SIG and got some ideas... here is what I came up with.

    About the layout: I am using Atlas HO dual coil switch motors mounted under table with a linkage to Atlas N Scale code 55 turnouts. Most of the turnouts will be dead frog, but I have made it possible to easily power the frogs if I wish to. I have about 82 of these turnouts placed and have linkage and motors to about 25 so far… long way to go.

    What I did.

    What I found were some wood disks that are 1.5" in diameter and 1/8" thick. They were purchased from a craft place online for about $6 for 100 of them. I will drill a 1" hole in my control panel and place the disk behind the hole creating a recessed area. I made some labels and printed them on my printer for the face.

    I am using a DPDT mom (on)-off-(on) switch and LEDs to indicate turnout position. One side of the switch controls the power from a CDU to the twin coils of the switch motors. The other side control a 12vdc DPDT relay mounted next to the switch. One side of the relay is used for the LED indicators and the other side may be used for what ever… either power routing for the frog or on layout turn out position….Guess it COULD do both.

    Here is a pictures of my prototype disk.
    Bigger pictures listed below.






    Red wire is incoming + from the CDU

    Blue and Yellow wire are outputs to the switch machines

    + and - are for the 12vdc to run the LEDs and relay

    Pics are not great. I am still learning about the macro capability of my new camera. Hopefully it will get better.

    Costs of this setup:

    Switch - $1,10

    LEDs - $.40

    Relay - $1.49

    Resistor - $.05

    Wood Disk- $.06

    Printed sticky label?? $.02


    Total $3.12 each

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