Roadbed in a helix

[markie97]

I'm using 1/2" plywood in a helix (HO scale) and plan on screwing the track directly to the plywood with no roadbed. If I do use roadbed it would be N scale because it will save a 1/16" in height (1/8 vz 3/16) as my clearances will be tight. Using screws I'm assuming I will not get much sound deadening from the roadbed. Eventually I plan to have most of the helix enclosed but will leave a portion open for viewing.

Anyone have experience with this? Pluses/minuses?

Thank you,

Mark

[carl425]

Here's one I built.  The top lap has Homasote roadbed on it since it was going to be visible.  I can't hear any change in the sound level between the top lap and the others.

Take the clearance, and therefore the reduced grade, and forget the roadbed.

[rrebell]

And if you want to save more clearance you could rout out the plywood, save another 1/8".

[RR_Mel]

I used ¼” plywood with closer bracing and HO cork for my 32” radius 3½% grade Helix.  I ended up with 3¼” clearance using Atlas Flex code 100 rail and Midwest cork.

 

Its 29 years old, its very strong and no warping.  Wood screws and Elmer’s carpenter glue construction.  The ¼” was very easy to work with and it was well worth using thinner plywood to gain the extra clearance.

 

The only problem I’ve had was cold to heat expansion and that didn’t effect any of the wood.  I soldered the rails and as the rails expanded and contracted for a couple of years the rails broke away from the plastic spikes on the Atlas track and I had to replace almost all of my track.  When I replaced my track I used non soldered track joiners with 1/64” gap between the rails and that took care of the temperature swing problem. 

 

My layout is in our garage and the temperature would vary between the low 30°s January to 100°+ in July.  I added an additional R30 insulation to the garage in 2010, now the cold to heat ratio is about 30° max.  Should have done that when we moved into the house in the 80°s    

 

The Helix built on ¼" plywood has alwasy worked great.

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[rrinker]

carl425

Here's one I built.  The top lap has Homasote roadbed on it since it was going to be visible.  I can't hear any change in the sound level between the top lap and the others.

Take the clearance, and therefore the reduced grade, and forget the roadbed.

 

 If you really crank the sound volume up (I was praying there was no narration or horn that was going to blow my speakers out), it does seem a tad quieter once all the cars hit the start of the homasoote, but the squealing hides most any other sound - is that a Loksound decoder with automatic flange squeal, or is it just a horribly noisy mechanism in the loco?

 It all depends on how close you are cutting things. A helix really shouldn't be at your minimum radius for a multitude of reasons, but if you are determined to squeeze as much as possible into a space, something has to give. About the only thing that can give is roadbed, or else the grade will have to increase. Unless it's the only grade, the helix shouldn't be your maximum grade, either.

                           --Randy

 

[railandsail]

RR_Mel

I used ¼” plywood with closer bracing and HO cork for my 32” radius 3½% grade Helix.  I ended up with 3¼” clearance using Atlas Flex code 100 rail and Midwest cork.

 

Its 29 years old, its very strong and no warping.  Wood screws and Elmer’s carpenter glue construction.  The ¼” was very easy to work with and it was well worth using thinner plywood to gain the extra clearance.

 

The only problem I’ve had was cold to heat expansion and that didn’t effect any of the wood.  I soldered the rails and as the rails expanded and contracted for a couple of years the rails broke away from the plastic spikes on the Atlas track and I had to replace almost all of my track.  When I replaced my track I used non soldered track joiners with 1/64” gap between the rails and that took care of the temperature swing problem. 

 

My layout is in our garage and the temperature would vary between the low 30°s January to 100°+ in July.  I added an additional R30 insulation to the garage in 2010, now the cold to heat ratio is about 30° max.  Should have done that when we moved into the house in the 80°s    

 

The Helix built on ¼" plywood has alwasy worked great.

 

Mel

 

 

That's good to hear. I've been thinking of using a double layer of tempered hardboard (masonite) for the subroadbed.

 

And no track roadbed itself, as I want it to be noisy so I can tell if anything is wrong (in there).

[SeeYou190]

The most reliable helix I have ever seen was on my friend Randy's N scale home layout.

.

The helix was entirely made with Kato Unitrack. None of it was glued down. We used 5/16" wood cubes glued to the plywood to hold the track in place. Any maintenance (that was never necessary) would be as easy as snapping out a bad piece of track and installing a new one. No kinks at rail joints, 100% smooth radius, perfection.

.

-Kevin

.

[trainnut1250]

One opinion - don't used roadbed in a helix...the main reason? it takes extra time. (Sure, it also messes with the clearance as well) Having built a double tracked helix monster, I can tell you that time savings will matter to you as move through the construction process.

 

Guy