HO Helix

[Anonymous]

Does anyone have an opinion as to how to construct a 30" radius Helix in HO scale? Anything you can offer would be great!

Michael

[GMTRacing]

Michael,
There are several ways to do it, but you need to be more specific. The one on my layout is part of the scenery and is accessible from underneath where it is hidden and then from outside where it emerges to join a bridgehead. I constructed mine by laying out the i.d. and o.d. of the ramp then cutting it from plywood. The riser is plywood with 4 branches 90deg apart with notches cut out for the ramp. I added more branches so that the ramp (which is 1/4" thick is supported about every foot. A 60" diameter will yield a 188" +/- circumference so the minimum incline can be as little as 2%. There are plans and more information in several of the "how to build a layout books" or in the magazines. Good luck. J.R.

[dknelson]

Don't forget that a company now makes a "helix in a box" called EasyHelix. It advertises in MR and I think MRP. A friend has one and it works as advertised. You get the steel threaded rods, plastic molded roadbed, the whole works.
Dave Nelson

[Anonymous]

There is a section in How to Build Model Railroad Benchwork, 2nd Edition by Linn H.Westcott on building a helix.
Also you may want to down load the Helix Calculator.

[DMNolan]

Here is a picture of one. I built it by cutting four 90-degree sections to make one turn. The first piece I cut in a 110-degree section, which made sure the joints did not overlap. I used cut 1x4 as spacers for the levels. The track radiuses are 38" and 35". It is about 7' across. With a 30" radius helix, you will use about six sections of flex track per turn. Once you get your base grade worked out, the rest of the levels maintain the grade. This type of helix requires allot of cutting and waste of plywood. I got 6 turn sections per sheet of plywood. With my layout time an hour or two at a time, it takes me about 4 days to complete a turn (1 to cut the wood, 2 to lay the cork and track a 1 to wire the track) It gets faster as you go. This helix is about 12" leading down to staging. I am building another one, on top of this one, which leads up to the upper deck. I have completed about half of it.

[jwar]

Hi Mike. My helix looks about the same as Mark's helix above, double tracked and five turns.
The key is to have a good supporting frame work and level, as the weight could cause warpage later, used 3/4 ply with no warps nor cups in it. Also used a track sodering jig to get perfect track soder joints, as I did not want any problems with derails after the thing was built. Also routed 1/8 by 1/2 in wide notches under the track for wire feeders, keeping the wires neat and out of the way.

Some use all thread rods for supports as it could be adjustable. However if the frame is strong and all spacers are exact there is no need in releveling to grade.

Figuring out percent of grade and adding the height per foot to a level is paramount. used a three inch, six inch and two foot level with a block glued to one end to check and recheck as I built and tested each level.

So far my Helix has worked flawless, except for one uncoupling at the top, and the consist having a cornfield meet at the bottom of the grade,LOL. ...John

[johncolley]

Yeah! don't forget to make the vertical curve at top and bottom very gradual. Any sharpness there will allow couplers to come apart. I ease into and off of grades by shimming a little at a time 3 to 6" apart.

[Anonymous]

FWIW I built my helix out of clear 1x6" white pine and cut an angle at each end of each piece to get the curve. It takes 12 pieces to make a circle, but they cut real fast and the waist is minimal. The length of the piece determined by the radious of the circle. And the pieces were joined with "biscuits" and glue. The vertical spacing is controled by threaded rods with nuts going thru metal plates that are connected to the bottom of every other joint. Worked pretty good, has been in use for over ten years. Make the start of the grade small (1/2 %) so the cars do not pitch up or down, very important if you run long equipment it could bottom out on the rails.

Gramps Railroad

[jkeaton]

RMC had an excellent article recently on making helixes out of straight pieces of wood, as Gramps Railroad describes. If you're trying to keep the percent grade down on your helix, look for thinner supporting materials - 3/4 inch ply is good and stiff, but thinner plywood with a stiffener rib glued on one side would buy you more space and a lower grade, if you need it.

Personally, I've always wondered about making a helix with sheet metal supports, ribbed or bent for strength - but I suspect you'd need a sheet metal shop to make this work. The idea of using threaded rods for vertical support sounds great for making those gradual transitions in the vertical curve at the top and bottom.

Jim

[lesterperry]

I agree with DMNolan on the construction useing blocks of wood for risers. I had 2 in my layout at one time but took them out as i didn't like not seeing my train for extended time. I had no problems with them but the still made me nervous. One trick Idiscovered when building them which I have now incorperated in my entire layout is staggering my rail joints. When you make your turns the inside rail becomes longer. Dont cut it off, slide the rail in the next section out to allow room for the first one. You will have to cut the cleats off of 2 ties to make room for the connector. Continue this process untill the long rail is just too long to handle. (About 3/4 length) then cut one to make it about 1/4 length and continue. This will make for much smoother turns and it is prototipical. As I said my entire layout is now done this way no joint other that at a switch is closer than about 1 foot. Good luck and be patient building it. One more thing I typically pull 35 car coal trains and they went through 36" radious helix with no problem.

[lyctus]

Hate to be thumpin' the tub for the opposition, but the article by Art Van De Water in April RMC on "Curves from Straights" ,is a pearler for helix builders. It is actually better than the recent RMC article on helix building for helix construction. I've tried it and it is very economical. Due to space limitations I will be building my helixes double tracked with Atlas Code 83 24" and 22" curved set track. Beats all the hassles associated with flex track on the curve. I will put lotsa electrical connections on the set track and because it is out of sight trackage, I don't need to fret about the funny end tie mouldings on the set track.

[Anonymous]

Lyctus,

I would double check those radii with the equipment you are going to use....I found that my larger locos needed more clearance than 2" on center to pass each other without catching something. Maybe 21.5" and 24" or 22" and 24.5". You will probably be OK if you are running small stuff and no long passenger cars but if you are running bigger stuff....Test it first. It would be a bummer to build a double tracked helix that has only one usable track......

FYI: I got a four turn double tracked 30"/32.25" and three turns of 30" helix out of two pieces of 4X8 ply with pieces left over by cutting out 1/4 turn sections. The drawback to the method listed in the RMC article is glueing together eight pieces of wood for every turn of the helix....That is a lot of glue joints......The disadvantage of the 1/4 turn method is that you spend more time cutting out curved pieces. I borrowed a buddies' band saw. Made quick work of the cutting.

I laid out each full rotation on a flat table to tweak em' and then glued em' in place on the helix....I laid flex and yes, it took a while to stagger the curve joints, but the thing runs smooth as glass. I also laid out, cut and soldered each rotation of track on my work table and then carried it over to the helix to instal it. Lots of fun carrying a 5' diameter circle of track (easier with a buddy to help) but it all worked out fine in the end. code 100 flex is very forgiving...

Helix building can be tedious but was surprised how quickly it went..

[lyctus]

Thanks for your comments trainnut 1250.I am in test mode at the moment, and I run fairly short stock, biggest are K4 locos and 60' passenger equipment. I do this deliberately as I have this thing about long stock on short pikes.And it fits my 1950's theme. Testing shows adequate clearance between 22 &24" radii. I will carefully recheck though!
As to the benchwork, you are right, there is a bit involved in the VanDe Water method. I have built a few layers of helix using the method and I have a wicked workshop with all the stuff. Benchwork is actually one of my favourite parts of model railroading, so I revel in the biscuiting and glueing ! Comments on flextrack noted, but somehow I fight with flex track on constant tight curves. I will stay with the setrack for the helixes and use the flextrack out where the track is seen.
I don't belong to a train club, I run a business which is time and energy demanding, but I really enjoy the exchanges on this forum.Thanks for you comments.

[ericboone]

I was in a club and one member built the helix by cookie cutting 1/8" boards that each made up about 45 degrees of the turn. Two 1/8" boards were stacked glued together such that the boards overlapped half of the 45 degrees. This assembly formed a very strong and smooth (no verical kinks) but thin roadbed. The roadbed was supported on the sides with 1 x 2s with notches cut at the correct height to support the roadbed.