3-Rail Wheel Gauge???

I've never seen such a thing. I wonder how well one would work, since many manufacturers have all different wheel/flange profiles anyway. Your 2-Rail, NMRA gauge is obviously designed fro SCALE flanges.

I smell a business opportunity here, Bob.

Made your own and sell them here.  Maybe even use the NMRA standards,  

Then again, do 3-rail modelers care all that much? 

Then again, do 3-rail modelers care all that much?

Martin, I would hope so.  I have 2 MTH 2-8-0 Railking steamers, 1 keeps derailing and the other has no problems.  A wheel gauge would (hopefully) rule out any problems with the gauge of the wheels.

I know the NMRA gauge ain't cuttin it for 3-rail wheels, the distance between the back of the wheels won't even fit in the gauge.

The one 2-8-0 that keeps jumping off the track did find a problem in my trackwork that has been there for years (but not discovered by any other engine).  I had a slight dip in a curve and had to insert a popsicle stick under the ties to level it (after removing a foot of ballast).

IMO    Interesting to note that we had spent a fair amount of time on Weaver plastic truck cars that seemed to de-rail all the time.   We noted that de-rails were usually on switches or crosses where there was channeled guides. In most cases the wheels would ride-up on the guide sections of the switch or cross and de-rail.  Conclusion was that the wheels were too-close-together.   We adjust the wheel set out, so that the flanges would negotiate the restricted areas of the switches or crosses.  De-rails significantly decrease.  

Maybe you could use an Atlas track cross as a wheel gauge, that's what we used.

Fort Pitt Highrailers

 Mike CT  

No shortage of those 'round here,

quote:

Martin, I would hope so.  I have 2 MTH 2-8-0 Railking steamers, 1 keeps derailing and the other has no problems.  A wheel gauge would (hopefully) rule out any problems with the gauge of the wheels.

According to the Postwar Lionel factory service manual, not all engines had their wheels gauged the same. They recommended using a know good pair of wheels to determine how to gauge wheels being replaced.

Maybe I can make a master out of steel and get one of the 3D printer guys to pop out some copies!!!

Thanks CW for that info!

Actually, I do the resin casting for one of the coupler height gauges in both O and S scale,

It isn't that hard to make one for yourself.  If it is just the flange spacing you are after, some scrap brass and a Swiss file will put you in business in less time than it takes to read these posts.

I have 1 1/8" track gauge, and was able to make a gauge checker in about three minutes.

This is true for you (and I) but maybe not for others.  And a resin one will not short out the track,

OK, so if I want to make a gauge, where do I start?  I would think the distance from the back of 1 wheel to the back of the other would be a constant, but knowing how all the manufacturers love to be different, is that distance really "standard"?

If not the back-to-back measurement, then what?  There's a lot (width) of angled tread to deal with if I have to determine where the rail rides (is it the middle of the tread width?).  I would think the back-to-back would be the common and let the contact between wheel and rail fall where it may.

Then there's wheels that aren't "fast-angle" wheels.  I noticed most/all of my Weaver 3-rail passenger cars have basically flat treads (maybe a 4-sided gauge with different tread designs, one per side).  Just how many different designs can I expect?

There are NMRA standards, but I'd seriously recommend that you set a standard for what truck(s) you use on your layout.  It's a variable that you should consider eliminating or at least minimize.

95+% of the trucks under my cars are Athearn with IM wheelsets.  I just sell off everything else but for a few exceptions.

I found the Weaver plastic-truck wheelsets were over-gauge compared to Lionel ones.

How so? not by derailments but with friction. During my days of floor layouts, I would build large loops that ran from room to room, using 072 curves so I could run long trains. One of those was a unit grain train comprised of Lionel and Weaver ACF hoppers, pulled by a Pullmor-motored SD40 and a Williams SD45 (when they were equipped with 540 motors). This whole arrangement was powered with a MRC Trainpower 027, an admittedly under-powered transformer.

I noticed that if I tried to increase power to maintain speed when the Weaver cars were traversing the 072 curves (they ran grouped together in the train), it would often trip the breaker. It wasn't until I was able to repeat the results with a pair of K-Line S-2's (which aren't known for drawing much current) that I started comparing the Weaver trucks with the Lionel ones, and found that while the back-to-back gauge was the same as Lionel, the flanges were much thicker, making the wheelsets overall over-gauge.

The additional friction manifested itself in 072 curves, where a sufficient number of wheelsets could "gang up" and raise current draw beyond what the little MRC could provide.

---PCJ

There are a couple of illustrations/specifications of wheel gauge in the Lionel service manuals.  The 773 Hudson, for example, was gauged on the narrow side (presumably to prevent flange-binding on the O31 curves commonly in use.)  Some shorter-wheelbase locomotives might have been gauged a little wider to prevent hunting from side-to-side as they traverse tangent track.  These are the only "standards" I know of for 3-rail.

   My subjective impression is that early MTH Premier steam locos are gauged a little wide for tubular track but I've never measured.   Good question!  -Ted

I'm surprised that a 100+ year old hobby has never had a tool to measure track and wheels

Guess I'll measure a few wheelsets and determine what the best approach is going to be.

Next question, if I find wheels too wide or narrow what am I going to do about them?  How easy are they to move?  I have a gear/wheel puller for those that are too close together and a vise if I need to hammer them closer.

I don't know what others are going to do, but I predict that you are converting to 2-rail, where such things are cut and dried.  And you won't even have to insulate things!

I've never seen one. The problem with 3-rail wheel sets is that they were designed around supporting tubular track and sharp curves. They've had the wheel backs closer together than 2-rail wheelsets which is why they don't work smoothly on 2-rail turnouts. That back-to-back distance has been inconsistent over the past several decades as has been the wheel diameter, flange height, and wheel taper. Modernly, they're doing better. With the movement toward flat-top rail, I'd like to see the hi-rail wheel set changed to a Code 200 tread width, a .062 flange, an RP25 taper, and a back-to-back distance matching 2-rail wheel sets -- essentially an enlarged 2-rail wheel set (single-insulation optional). This would allow the wheels to traverse most 2-rail turnouts and crossings unmodified while supporting operation on current 3-rail turnouts and crossings.