Flange-ways in our Turnouts

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NP2626

Active Member
#21
I'm not so sure that most of our 'model size' wheels have same 'tapers' that the real ones do?



I need to get out my calipers and play with them a bit more as well.
I have looked at thousands of wheel sets over the years and have never seen a model railroad wheel set that doesn't have taper.

Here are Digital calipers from Micro-Mark <https://www.micromark.com/search?keywords=Digital%20Caliper> Good deals can also be found at Ebay for Digital Calipers.
 

beiland

Active Member
#23
Trucks of Multiple Wheel Sets

Another consideration we need to make about turnout problems is NOT only the passage of a single axle wheel set thru them, but rather the passage of a 'truck' full of wheel axles thru them.

There must be some sort of video(s) covering this subject??
I'm sure I remember seeing some good videos on this subject, but I've not found them so easily with a quick search (rather working on new layout plan).

Anyone else found some?
 

NP2626

Active Member
#25
I thought I would take a look at the Wheel Taper of the few different manufacturer's wheel-sets that I have. The vast majority of my rolling stock have the older Life Like Proto 2000 wheel-sets. Since I had to find a new manufacturer when Walthers decided to stop producing the original style Proto 2000 wheel-sets, I have had to search for a new supplier. I felt that Kadee maybe could fill the bill; but, have tried a few others. First of all I am talking HO Scale and specifically Code 110 width. Over the 10 LLP2K wheel sets I checked, I found them to be very consistent. I found that they have a tread width of .070 and that the taper over that length was slightly more than .010. In other words, the diameter of the wheel at the flange was .020 larger than the diameter at the outside tip. RP-25 states that the taper is supposed to be 3 degrees. The Kadees wheel-sets I checked showed an .008 taper. What was surprising was that I found the diameter near the flange and at the outside edge of the wheel to be very consistent among a manufacturer's wheel-sets! I didn't feel the difference between LLP2K and the Kadees to be a significant difference.

I have a very few Reboxx Code 88 wheels. Code 88 wheel-sets have a tread width of .050 and I found the taper to be the same as the Kadee wheel-sets at .008. I'm not going to do the trig to determine if the .008 and .010 taper is 3 degrees, per RP-25. To do the best job of calculating the above dimensions, a person would need access to an Optical Comparator. This would also easily allow checking the taper in degrees.

The above research was done using my old Helios Dial Calipers and was done using my best abilities.
 

NP2626

Active Member
#27
Thanks very much for that info Mark,...very informative about taper.
I don't know how much the taper in the wheel sets have to do with the depth of our flange-ways. However, my guess is cumulatively flange-way depth and wheel taper do effect how a wheel runs through a frog. On full sized railroads the width of the Frog's Flange-Way is never large enough that the wheel would not be supported on it's tread. It's the fact that the width of the Flange-Way is so large on model railroad track that we see these dipping problems with our wheels as they fall down into the bottom of the Flange-Way. All in all, what we have now works; but, simply put, could be better. I think Willie's idea about gluing a .020 thick plastic shim to the bottom of the flange-way would correct this issue. Also, as Chet has demonstrated, not every turn-out has this issue.

Perhaps we should be studying RP-12 thru RP-13, RP-13.5, .6, .7, .8 to make sure we understand what is expected of the track manufacturers. Certainly, RP-12 and 13 have something to do with it!
 
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NP2626

Active Member
#28
Since all of my turnouts except for a Double Cross-Over (Scissors) are Atlas Custom Line turnouts. I wonder if Peco, Micro Engineering; or, other turnouts have these issues?
 

tootnkumin

Well-Known Member
Staff member
#29
As I've mentioned, all the turnouts at the club are Peco 100 Streamline. Last night, I started running in one direction, no problems, all going well. Changed direction on the reversing loop and had derailments in two different locations. The worst one was not on the points themselves, but on the frog. The last 4 cars all decided, one after the other, and after rerailing each one, following in sequence, to go off the direction of travel and use the frog itself as the diverging point.
 

NP2626

Active Member
#30
Toot, as related to this conversation on the "Flange-Ways in our Turnouts", I was wondering about the depth of the flange-ways of: Pico, Micro Engineering; or, other turnouts. Do you have any idea why your cars derailed? Do you think it may be related to the wheel falling into the flange-way?
 
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NP2626

Active Member
#31
To be clear, my only interest in this conversation is because of the jostling of the locomotives and cars on my layout as they pass through some of the turn-out frogs on my layout. I am not having derailment problems with these turn-outs. The action of the cars and locos is similar to a car hitting a pothole. This is happening because the wheels fall off of the rail head into the bottom of the flange-way, generally .020 below where the flange of the wheel normally rides. On full scale railroads the tread of the wheel never leaves a railhead so falling into the flange-way never occurs. However, because of the build up of tolerances and how turn-out frogs are made for model railroad track, the flange-way (at least for Atlas turn-outs) is much larger than it needs to be. Adding a .020 thick shim to the base of the flange-ways on my Atlas Custom line turn-outs will cure this problem. I know this because I have experimented with doing so. I use plastic shims and there is no worries about electrical shorting. However electrical continuity is lost for the very short time the driver or diesel drive wheels are in the bottom of the flange-way.

So, for me this issue is only about an unrealistic lurch my cars and locos make when crossing some of my Atlas Custom Line Turn-out frogs.

Atlas Code 100 track and turn-outs may not be the best products on the market. However, they can be made much better with some extra work. At the time most of my track was laid, Atlas was still in the mainstream, Code 83 was coming on; but, much more expensive!
 
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tootnkumin

Well-Known Member
Staff member
#32
Looking at the turnout afterward, I would say it's wear on the sides of the rails, allowing the wheels to wander off course, so falling into the flangeway is the probable result. The tracks get used for all sorts of different rolling stock scales. If it will run on code 100 HO, it does. It would be interesting to compare Code 100's gaps between stock rails and frogs etc, with the smaller codes. I suspect they would be narrower, in anticipation of narrower wheel treads being used. If wheels are correctly gauged and check/guard/frog rails are correctly placed to prevent excess side movement of the wheels, then the depth of the flangeway, if deep, shouldn't matter. Not deep enough, yes, if the flanges can make contact. If the wheels can't leave the inside edge of the rail it's traversing, then it shouldn't fall into the flangeway.

The main thing I think that caused my little excursions would be wear on the point of the frog, allowing the gap between it and the stock rail the wheels were aiming at to get to be too far away, combined with too wide a gap between the opposing guard and stock rails controlling sideways movement of the axle. Too an extent, it's the fault of using too wide of wheel treads on most of the production rolling stock. If we were to use the narrower tread profiles, we would be forced to make sure our wheel guaging was accurate. Then we could also make sure that the gaps between rails and guard rails was narrower, thereby eliminating side to side oscillation of the cars. We could still do that anyway, even though the treads may be wide, doesn't matter if they overhang the outside of the rails, does it?
 

IronBeltKen

Lazy Daydreamer
#33
... We could still do that anyway, even though the treads may be wide, doesn't matter if they overhang the outside of the rails, does it?
Interesting observation, Toot! I learned one of the "down sides" of wide wheel treads the hard way ~15 years ago, after I laid track for my steel mill. I wanted it to look the way it did in prototype mills, i.e., rails sticking out of the dirt. So I embedded my track in tile grout and made sure the grooves were deep enough on the inside edges. I totally forgot about the extra-wide wheels treads, and when I test-ran an SW7 on it...ouch! It stalled out every 4-6 inches!



I wound up having to gouge-out little depressions along all the outside rail edges to ensure the loco wheels would always make contact. Lesson learned!
 

tootnkumin

Well-Known Member
Staff member
#35
When they resealed (tarseal) the grade crossing not far from where I live, they just ran it almost level with the tracks and allowed the weight of the passing trains to cut the grooves for the flanges. 'fraid our trains don't pack that sort of "heft" to allow that.
 

NP2626

Active Member
#36
I have just scanned to NMRA RPs for the depth of the flange-way of the frog and could not find any reference to this dimension. Does anyone have any information on what this should be and if so, where did you find a reference to this dimension? I looked through RP-12, RP-12.x TN-12 and all of RP-13.
 

fcwilt

Active Member
#37
I have just scanned to NMRA RPs for the depth of the flange-way of the frog and could not find any reference to this dimension. Does anyone have any information on what this should be and if so, where did you find a reference to this dimension? I looked through RP-12, RP-12.x TN-12 and all of RP-13.
Did you check S-3.2?

Frederick
 

NP2626

Active Member
#38
Frederick, NMRA S-3.2 does describe how deep the frog flange-way should be, .025.

My study of what I found with my Code 100 Atlas Custom Line Turnouts has been brought forward here:

"My findings for the flange-way depth of some of the turnouts on my layout are as follows: For Atlas Code 100 Custom Line Turnouts I found by checking 11 turnouts that the depth of the flange-way of the frogs varied between .044 to .050 in depth. I measured one Atlas snap switch, with a plastic frog at .056 deep. My Shinohara Double (Scissors) Cross Over had 8 frogs on it and all measured .060 deep. So, what does this mean? Without knowing the depth of the flanges on my locomotives and rolling stock, nothing!

So the next step will be to take some measurements of flange depths."

I also thought I would bring forward what I found as far as Flange Depth of my wheels were:

"I took 16 readings off of various manufactured wheel sets and found the flange depths to be consistently around .025 deep. Variation ran from .024 to .030, however, the .030 reading was taken from a Varney Docksider (Little Joe) which is possibly older than 60 years. So RP-25 is older than July of 2009, the latest revision".

​Obviously Atlas Code 100 Custom Line Turnouts are not compliant with NMRA RP S-3.2
 

beiland

Active Member
#39
Depth of Flangeways

I think by now we find that most commerically built turnouts are a bit deep for our modern American models with small flanges as found on RP25 wheels.

But in general the depth of the flangeways does NOT seem to be as important as width of the flangeways at the outer guard rails. and the inner wing rails of the frog. And this is particularly true if we are running the wider wheels rather than those skinny scale wheels.

Personally give me the wider wheels (with the small scale looking flanges), for the most trouble free running.
 

NP2626

Active Member
#40
I think by now we find that most commerically built turnouts are a bit deep for our modern American models with small flanges as found on RP25 wheels.

But in general the depth of the flangeways does NOT seem to be as important as width of the flangeways at the outer guard rails. and the inner wing rails of the frog. And this is particularly true if we are running the wider wheels rather than those skinny scale wheels.

Personally give me the wider wheels (with the small scale looking flanges), for the most trouble free running.
I pretty much agree with you about the Code 110 wheel sets. While trying various wheel set manufacturers goods, I purchased some Reboxx Wheel-Sets from ModelTrainStuff. The wheel width was not described for Reboxx Wheel-Sets at MTS. I assumed they would be Code 110. They where not! All Reboxx Wheel-Sets are Code 88 per RP-25. I have used these Reboxx wheels and found they seem to work O.K. However, I have more confidence in the Code 110 Wheel-Sets.
 



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