HO engine wheel flange measurement

[doctorwayne]

SeeYou190

...I have a package of metal replacement wheelsets for my Rivarossi passenger cars that are supposed to be RP-25. I have not installed them or checked them yet....

I use Kadee 36" wheels in my Rivarossi passenger cars, and the only other change needed is a slight trimming of the cast-on plastic brake shoes (no need to remove them completely)...

This one was a Rivarossi coach, but since it was the correct length for one of the CNR's Express Horse Cars, I couldn't resist modifying it...

...and that started my interest in changing other passenger cars into head-end cars of various types.

Wayne

 

[RR_Mel]

 

I have been running Rivarossi deep flange locomotives on Atlas code 83 track and Atlas code 83 turnouts for over 30 years and never had a single derail caused by the large flanges.  About 15 years ago I replaced two Atlas code 83 turnouts with Peco code 83 curved turnouts and again never a problem.

 

When I first laid my track in 1989 I wanted a code 83 double crossover and none would pass my Rivarossi Cab Forward without problems.  I went with a pair of Atlas code 83 turnouts as a single crossover for 15 years until I made my own double crossover from Atlas code 83 #6 turnouts.  I’ve never had a derail in my Mel double crossover.

 

https://melvineperry.blogspot.com/2012/06/june-25-2012-my-double-crossover.html

 

https://melvineperry.blogspot.com/2014/07/july-27-2014-revisiting-my-double.html

 

I now have 20 large flange Rivarossi articulateds that run flawlessly on my code 83 layout.  I can’t remember any derails not caused by the operator, Me.  

 

EDIT:

My blog post says the hidden track is code 100 but in the summer of 1993 I replaced all the code 100 with code 83.  I made a mistake of soldering all the rail joiners and the extreme temperature swing (30° to 108°) buckled all the code 100 track.  The code 100 track wasn’t ballasted.

 

 

Mel

 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

[SeeYou190]

BEAUSABRE

Looking back, it's rather surprising that somebody didn't develop and market aftermarket wheels with the RP25 contour for AHM/Rivarossi equipment.

I have a package of metal replacement wheelsets for my Rivarossi passenger cars that are supposed to be RP-25. I have not installed them or checked them yet.

I seem to remember an advertisement in Model Railroader years back for RP-25 replacement drivers for the Rivarossi 0-8-0. Back in the day, that was the only decent model of an 0-8-0 on the market. I can imagine there was some demand for compliant drivers at least for that model.

-Kevin

[cjcrescent]

BEAUSABRE

Looking back, it's rather surprising that somebody didn't develop and market aftermarket wheels with the RP25 contour for AHM/Rivarossi equipment...

 

Rivarossi products were manufactured to the NEM (European) standards at the time, which called for the larger flanges. There was IIRC, a manufacturer of replacement drivers, Greenway Products, but I believe that they are out of business. I know that they made replacement drivers for brass engines but don't know if they made them for Rivarossi/European products.

[BEAUSABRE]

Looking back, it's rather surprising that somebody didn't develop and market aftermarket wheels with the RP25 contour for AHM/Rivarossi equipment...or did I miss something? Second, I don't remember any particular controversy around RP25, but I was in my early teens, so maybe it went over my head. What was the deal?

[dknelson]

The NMRA standards gauge would be the easiest and fasting way to check if a given set of flanges will be OK with Code 83 (or 70) rail.  And you should have one anyway for the other things it is useful for.  

The AHM/Rivarossi flanges from the 1960s were unfortunate and a setback for the hobby since so much of the stuff was sold and for practical purposes all that investment in trains probably kept many guys, myself included, from moving away from the oversized Code 100 rail.  It also meant that nearly every AHM/Rivarossi steam locomotive had underdized drivers because the huge flanges needed clearance from either other.  This did not look too awful on things like the IHB 0-8-0 or the N&W 2-8-8-2, but the NYC Hudson, otherwise a nice model, looked just plain wrong with its small drivers.  

Even if you grind down the flanges, as Dr Wayne shows how to do, there is still the issue that the wheel contour for the tread is more flat than the NMRA RP25 contour, and also lacks the RP25 fillet between wheel tread and flange.  The RP25 tread contour has a slight angle to it which, together with the small fillet between tread and flange, play an important role in good tracking.  Considering how controversial RP25 was when it was new it is impressive how durable a recommended practice it has been.

As I recall eventually AHM and then IHC had Rivarossi and their other European sources decrease the flange depth but still not to RP25 standards.  And as I recall they still retained the undersized steam locomotive drivers.

Dave Nelson

[rrebell]

Question is how old, only thing I ever had issues with was Riverassi and I run code 70. Never had an issue with brass but then I didn't have really old stuff, all my stuff being  late

70's or newer

[gmpullman]

I haven't observed oversize flanges in any of the brass imports that I'm aware of, Tom. The biggest offenders seemed to be the European manufacturers of the time, Rivarossi and the Yugoslovian AHM stuff. They may have been copying tha Marklin wheel profile.

Most of the North American toy train market was using code 100 and the "sticking" point was the frogs as I recall. Some of the frogs were designed to actually lift the wheel tread off the points as the wheel passed through but the overly large flanges were simply too much for them to handle. I believe there was a lot of flange-depth filing going on back then.

Coronation_Gauge by Edmund, on Flickr

Regards, Ed

[tstage]

gmpullman

"Pizza-cutter" flanges were prevalent on many of the imports back in the '70s and early 1980s.

Ed,

Would that also be true for brass during that time?  Or would they tend to have more prototypical flanges being on display?

That would need to be a consideration for my next layout if deeper flanges were common.  I hadn't noticed any tracking issues on the loop of Code 83 track I use for test running & breaking in the 70s/80s brass that I've picked up in the past few years.

Tom

[gmpullman]

Hello,

"Pizza-cutter" flanges were prevalent on many of the imports back in the '70s and early 1980s. I recently took a photo of this Rivarossi NYC Hudson:

Rivarossi_pip-frame by Edmund, on Flickr

They were OK on most code 100 rail but would "ride up" on some turnout frogs and guard rails that didn't have deep enough clearance for them. On some brands of code 83 track they would bump on the "spikes" and definitely have trouble negotiating turnouts and crossings.

NMRA's RP-25 flange has become the norm for operation on code 83 rail.

An NMRA standards gauge is helpful to make sure your flanges conform to the RP-25 recommended practice.

Rivarossi-gauge by Edmund, on Flickr

Good Luck, Ed

[doctorwayne]

1arfarf3

1. What would flange depth need to be to not derail?

I can't see why the flange depth, unless it were totally ridiculous, would cause a derailment.

I searched through my older wheelsets, and found one with a tread diameter of .531", while the flange diameter was .610", an over-all difference of .079".  Dividing that by two gives a flange depth of .0395"....nowhere near the .083" height of code 83 rail.

1arfarf3

2. What instrument is needed for measurement?

I use a dial caliper, which measures in thousandths of an inch...

This little Mogul...

...(much modified, as shown) had oversize flanges when I bought it, and while it ran okay, I didn't care for the look of the big flanges.  I replaced the wheelset in the lead truck, and those under the tender, too.

I didn't, however, have replacement drivers.  To cut down the oversized flanges, I connected wires from my workshop transformer to the loco's motor (body shell removed) , then, while holding the loco upright, with the drivers rotating at a medium speed, I used a cut-off disk in a fairly high-speed motor tool to use the face of the disk (not the edge) against the bottom  of the rotating drivers, touching each wheel flange lightly and only for a few seconds at a time.  This prevented the drivers' rims from overheating, as the drivers' centres were plastic.  It didn't take long to get all six drivers' flanges down to a more realistic size.

Wayne

 

[1arfarf3]

I have a few older HO engines and need to measure wheel flanges to determine if I would have a derailment problem on code 83 switches. 

1. What would flange depth need to be to not derail?

2. What instrument is needed for measurement?