Table I made a while ago

These list the real-life elevation changes (in inches, maximum of 6" prototypically) from one rail to the other, with HO associated dimensions required.

Edit:

I also found an FRA rule denoting maximum speeds for various radii. A sample of the table I made from it is listed below:

search

if you don't get responses from several other people, try the search box, because people have described their method in good detail on the forum in several different threads (be sure to search blog posts too).

I haven't done it, but my vague memory is one person added a new layer every 12" and built up to 6 layers in a curve that was long enough. That was for HO, IIRC all this correctly. 

Edit: based on the below responses, I suspect my memory on the details was faulty. I now don't trust my 12 inches between additional layers number. 

Edit2: Lots of good stuff in this thread:  https://forum.mrhmag.com/post/super-elevation-questions-12199724

Works well

I used 1/4” masking tape (ordinary paper tape), starting at the beginning of the easement, adding a layer every 2”.  The tape is on the roadbed (Homasote in my case), at the outer edge.  Don’t remember exactly how many layers, but it was quite a few...I think 10 or so.  However, your automotive tape may be thicker than the paper tape I used.  And remember that for our models superelevation is purely cosmetic, so I’d suggest setting up a test section and trying different thicknesses until you find one that looks good to you.

I just use

balsa wood strips from my local R/C airplane shop for the elevation.   It's real easy to sand a taper on the ends.

Seems to me you would need to stack up a lot of tape for HO scale.  I'm not so sure how stable thin tape will be over time.  There's a lot of slippery glue in that stack.    Just sayin'............

.

I’ve had the mainline in and in operation for 15 years with no issues related to the superelevation.

Tried the balsa approach, but I found it hard to get a consistent taper at the ends.  With the tape it’s a lot easier to get consistent, smooth transitions.  Yes, it takes a few layers, but goes down quickly, and no waiting for the glue to dry.

I think this is a sound

I think this is a sound approach, but it helps to have a backup, even if to relieve boredom at time.  I haven't used the stepped end tape method in some time. I just rely on some clear plastic packaging that we're forever cutting open, hoping not to slice our fingers at the same time. It's fairly thin and can be stacked if needed.  I haven't found the need to go higher than the one layer, but if it doesn't seem to look right, shaking the grains of ballast a bit at the apex while lifting the tracks a bit seems to do the rest of the height gain.  If that process goes over-height, tapping at the apex gently with a paintbrush handle will reduce it.

kraft paper and matte medium

I used brown kraftpaper, glued down with full strength acrylic matte medium - because that was what was on hand, to slightly superelevate one curve on my layout. I don't remember how many layers there are. It was all done by eye. I traced the outer curve of the ties for the pattern to cut the paper. The bottom layer was also wide enough to reach the centerline of the track. Additional layers got shorter and narrower, again checking by eye as I went. The sub roadbed is Homeasote. The track was ballasted normally afterward. It has worked well for 25 years.

Got track to lay, interested it this.

The tables are interesting and useful.  I wonder if the Prototype super-elevation translates well into HO or the physics being different mean you need to tweak it some, to avoid string lining rolling stock.

What would be helpful is a guide to super elevation vs curve radii in HO.  I think super elevation improves the look of model trains on curves, but the trick is to get it right for good operation reliability.

I like the idea of making tape built up in layers.  Someone else posted their general rule of thumb her, but I lost track of it.

Superelevation

First if super-elevation in real life help train rolling through curves this is just a detail to put for our model because this has no incidence.

I'm not sure, but translating the real thing in this case to our model is the way to go.

I use in N scale 2 mm thick wood to super-elevate my curves.

This seems  a lot in N scale but this really show the cars bends over the curve, under this thickness the effect is nearly invisible

Probably for our model we need to accentuate this super-elevation a bit to see the effect; this has no consequence of the rolling capabilities of rolling stock or locomotives on my N scale layout

Tape on high side?

Has anyone tried sanding the top of the cork to make the inside rail lower instead of raising the outside rail?  Given the stiffness of model rail and the cushion of caulk gluing it down I doubt the sanding would have to be super precise....DaveB

My tape is 0.09mm

So if my tape is 0.09mm took awhile to find this and I want to get to around 0.040” which is what I used for shims before, I need around 12 layers which is 1.08mm or 0.0425” which I think is close enough.  3.7” in real world.

sound right?  I think my math is right.

Mike

Sounds about right to me.

I’d still recommend building a trial section to be sure you like it, though - both appearance and installation technique.

Math

Update:

In case someone tries the same thing I'm doing with 3M precision automotive green masking tape for Superelevation.

So my math although correct was off somehow.  I got to six layers and I could not figure out why this seems to pretty much match my 0.40" styrene strip.  7 layers is definitely higher.

So after checking with my Dad (he who owns obscure but useful tools) he gave me a metric machinists micrometer(say that ten times fast), a device far more precise than my hobby callipers.  The micrometer says that the 3M automotive tape is actually around 0.18mm thick and not 0.09mm thick.

Why it is showing as twice as thick as what 3M says is beyond me, although I now notice it says on the 3m website under details for the tape that these measurements are just a standard guide and not to be used where precision is required.

0.18mm x 6 comes out to 1.08mm, which converted to inches is 0.043 which is close enough to 0.04 for my purposes.  Slightly higher but not by much.

So six layers seems to be fine. It's much easier to put down than trying to tweak the position of styrene.  Six layers of tape goes down very quickly.

I agree with others that 1/4" tape is very easy to put around curves. 3M also has a narrower tape of the same type but I think that would be more suitable to N scale as it's so narrow it would be hard to position correctly.

I used 8 layers of 1/4"

I used 8 layers of 1/4" automotive masking tape on my HO layout.  I used that on all curves regardless of radius and they varied from 30" radius to 72" radius.  I think it looks good and I have never had operational problems with it.  I stepped the layers in 2" long steps.  I started at the beginning of the curve.  In reality railroads use transition curves (spirals) before the circular curve and the superelevation is developed in the transition curve so that it is un full superelevation by the time it becomes a circular curve.  Anyway I liked how mine looks and runs.

Just wondering

If when they state the thickness of tape if they're measuring just the tape and not the glue? That could account for (some of) the discrepancy you were finding.

Lowering Inner Rail ?

Prototype super elevation is always done by raising the outer rail rather than lowering the inner rail.

Mark Vinski