Is there such a beast available? I know most 3-rail wheels are almost impossible to move but it would be nice to be able to at least check them out.
I have a NMRA 2-rail gauge.
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Originally Posted by Bob Delbridge:
Is there such a beast available? I know most 3-rail wheels are almost impossible to move but it would be nice to be able to at least check them out.
I have a NMRA 2-rail 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
Originally Posted by Bob Delbridge:
...a slight dip....
No shortage of those 'round here, 
Originally Posted by Mike CT:
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.
As information, we (Independent Hi-Railers, Midwest Division) discovered the same situation with Weaver plastic trucks on our modular layout. We then discovered that the metal wheel sets in this plastic truck were thicker than the wheels in Weaver die cast truck assemblies. When this was pointed out to Joe Hayter (sp) of Weaver, he took note, and eventually Weaver stopped offering plastic trucks. Try measuring the wheel thickness with digital calipers, and you'll be surprised.
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
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.
If you make one you will be able to market it to the g scale guys for their couplers as well. 2 scales from 1 product? Should be a money maker! Good luck!
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!
Originally Posted by Bob Delbridge:
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.
Originally Posted by bob2:
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?
Originally Posted by Bob Delbridge:
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.
Originally Posted by bob2:
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!
Bob, you may be on to something (I already have the NMRA gauge!)
Matt,
Are 3-rail wheels (for the most part) pressed onto the axle? I see some that have serrations on the axle so the wheels don't move but others don't have them.
I put a 3-rail truck up to the 2-rail gauge and the 3-rail is maybe 3/32" narrower.
Actually, being I'm starting to convert my steamers to battery power, I'm thinking of taking up the middle rail and keeping the current wheels.
Converting rolling stock wheels would be easy and cheap, but not so on the engines.
Talk about an oddball layout, I'd have battery-powered, remote controlled engines with fixed pilots and Kadee couplers, running on ex-3 rail track, running on 3-rail wheels, but without the center rollers. Passenger cars requiring lighting will be LEDs run off batteries.
I have always used the NMRA gauge as a place to start. The 3 rail wheels do not follow any standard that I can see depending on manufacturer and date. If one is using a true t rail track, it helps to check the track gauge all around.
regarding the wheels, once set to NMRA gauge, the wheels will likely be too tight and you can adjust until the truck tracks everywhere.
On switches there definitely is no 3 rail standard.
I know this is an old topic, but the problem still exists.
If I was to make a Hi-rail wheel gauge, what would be the defining measurement to check? Would it be back-to-back width of the wheels? For some reason I keep plopping the NMRA 2-rail gauge onto a set of Hi-rail wheels expecting them to drop right in. I've noticed that almost every wheelset I try, the backs of the wheels are "just" too wide, about 1/16" from going in. But they're all consistent. If I took even a scrap piece of brass and made it to slip between the wheels (whatever that measurement should be) then I could check every wheelset against it and it would be easier than holding a ruler up to the wheels.
Another topic...I spent the last 2 days cleaning crud off the wheels of my rolling stock, didn't want to do it but I noticed several wheels had buildup that was 1/32" thick! While cleaning them I noticed a lot of variation between tread angles, a couple of cars had wheel tread where the angle was almost flat but with large flanges. I'm running on Atlas, Micro Engineering, and Signature Switch 2-rail track and have not had any problems, other than thru a couple of my hand-built turnouts where I used too many spikes in the frog area.
Anyway, a while back I stated that, being I was running BPRC, I really didn't need to clean wheels and track because there's no requirement for electrical continuity. But there is a need to keep them clean to prevent derailments so cleaning accumulated dirt/grime off these places is still a necessary evil. Today I get to clean the wheels on all of my engines Woo-Hoo!!! Good thing is all I have to do is turn them over and turn on the switch. Another good thing is I only need to do this once or twice per year.
Bob Delbridge posted:I know this is an old topic, but the problem still exists.
If I was to make a Hi-rail wheel gauge, what would be the defining measurement to check? Would it be back-to-back width of the wheels? For some reason I keep plopping the NMRA 2-rail gauge onto a set of Hi-rail wheels expecting them to drop right in. I've noticed that almost every wheelset I try, the backs of the wheels are "just" too wide, about 1/16" from going in. But they're all consistent. If I took even a scrap piece of brass and made it to slip between the wheels (whatever that measurement should be) then I could check every wheelset against it and it would be easier than holding a ruler up to the wheels.
Another topic...I spent the last 2 days cleaning crud off the wheels of my rolling stock, didn't want to do it but I noticed several wheels had buildup that was 1/32" thick! While cleaning them I noticeda lot of variation between tread angles, a couple of cars had wheel tread where the angle was almost flat but with large flanges.
Bob, one of the problems you are going to have making a Hi-rail wheel gauge is that the contour of the wheels themselves is also not standard and that's going to make this very difficult unless you standardize your personal use/choice of wheels in use.
mwb posted:Bob Delbridge posted:I know this is an old topic, but the problem still exists.
If I was to make a Hi-rail wheel gauge, what would be the defining measurement to check? Would it be back-to-back width of the wheels? For some reason I keep plopping the NMRA 2-rail gauge onto a set of Hi-rail wheels expecting them to drop right in. I've noticed that almost every wheelset I try, the backs of the wheels are "just" too wide, about 1/16" from going in. But they're all consistent. If I took even a scrap piece of brass and made it to slip between the wheels (whatever that measurement should be) then I could check every wheelset against it and it would be easier than holding a ruler up to the wheels.
Another topic...I spent the last 2 days cleaning crud off the wheels of my rolling stock, didn't want to do it but I noticed several wheels had buildup that was 1/32" thick! While cleaning them I noticeda lot of variation between tread angles, a couple of cars had wheel tread where the angle was almost flat but with large flanges.
Bob, one of the problems you are going to have making a Hi-rail wheel gauge is that the contour of the wheels themselves is also not standard and that's going to make this very difficult unless you standardize your personal use/choice of wheels in use.
Agreed, the contour of the wheels is far from standardized but the flange back to back distance has to be the same or you will have derailments on switches. The gaurd rails pull the wheels the correct way so they do not jump the frog. If the back to back measurements are all over the place I don’t think see how anything stays on the track.
I like hand laying track and the lack of a gauge is a frustration. I am going to see how Gargraves track measures up with the nmra gauge. If it is in spec you could use that and a wheel set that is representative of your fleet and sort of be ok.
Hey Martin, thanks!
Based on what you've said and from what I've seen about the wheel contours, I figured using the distance between the backs of the wheels would be the best choice. Problem is I don't know if that measurement really means anything, maybe measuring the distance between the outer surfaces of the wheel flanges on the tapered sides of the wheelset would be better. If that measurement was used as a standard, then at least we'd have a starting point. Different wheel contours would only raise/lower the height of the axle center line, making some cars ride a fraction higher/lower than others.
Surely the manufacturers have some criteria they go by when making wheels. They have to in order for them to run on all the different brands of track that are available. What we need to do is find out what that magic number is.
I sell them for P:48 and call them Gauge Blocks. That won't do you much good but I also make my own for other gauges, including O Scale (Ow5) and I suppose it would work just fine for O Gauge (3R). I cut a piece of tubing, in this case brass because I had it laying around, to the correct length and then cut a slot for clearance. Shoot a piece of PVC might work. I'll try to take a photos of one of the brass ones I made. I use NMRA standards. I assume this would be correct for 3R also. Your mileage may differ. So I don't get into trouble with The Powers That Be, none of this is an offer to sell. Jay
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Bob Delbridge posted: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).
I think 3 railers would care. I have had to adjust pilot trucks on some of my post war Lionel steamers because they would derail on curves because they were out of gauge. Once put back in gauge, they ran with out any problems.
The NMRA Standard for Hi=Rail wheelsets (not O-27) is
1.090 in, +0.003 in, -0.005in.
Buy a vernier caliper.
Guitarmike posted:I like hand laying track and the lack of a gauge is a frustration. I am going to see how Gargraves track measures up with the nmra gauge. If it is in spec you could use that and a wheel set that is representative of your fleet and sort of be ok.
Oh, you're going to love this, then. I was having gauge problems with some of my equipment, so I did some measuring a while back. To my surprise, I found variation in the track. It amounted to all of 25 thousands of an inch between various brands--and to my far greater surprise, that actually made a big difference in a few cases.
Gargraves is actually 1.270 between the rails, and I have had wobbly postwar cars where the trucks would fall down between the rails on Gargraves. Ross track varies a little, in my experience, but it seems like the number they shoot for is 1.260, which works well. I had some Ross that was actually gauged at 1.250 (you know... O gauge?) or even 1.245, and certain locos had flange binding on the curves. I worked it over with pliers until I got it close to 1.260, and the problems cleared up. Fastrack and Atlas are both right on 1.250, but the Fastrack is effectively wider gauge because of the rounded rail profile. I have an MPC scale Hudson which is rated for O-31 tubular but will not run on O-36 Atlas. Yet it handles O-36 Fastrack just fine, even though both are exactly the same gauge. The difference is all in the rail profile.
If you are laying your own track, I think the number you want is probably 1.260, as long as you are not using rail with a razor-sharp corner profile.
The main takeaway (philosophically speaking) from my experience is this. The lack of actual standards in 3-rail is the product of a difference in philosophy between the scale modeler and the maker of toy trains (which is what 3-rail is derived from, of course). The scale modeler wants to reproduce the real thing accurately, so he adopts standards, and tempers his expectations for his own layout and what he will be able to run on it, realizing that there are some things he just can't do, if he is going to maintain an acceptable level of realism. But the toy train maker asks, "how much locomotive can force around this curve?" He asks that because his market is more interested in having a big locomotive than in having a realistic locomotive--"they're toys!" say they. So the toy train maker doesn't follow standards; the toy train maker cheats. He has been cheating for a hundred years now, and if there are still toy trains a hundred years hence, he will be cheating still. And as long as people expect the 3-rail scale trains to run on the same tracks as the 3-rail toy trains, there never will be any standards.
For this reason, I think any 3-railer (even a toy guy, like me) who wants to run equipment from different manufacturers, or even different eras of the same manufacturer, will just have to be reconciled to the idea of tinkering with the trains until they run on his layout.
None of that answers OP's question of course, except to say that there probably isn't an answer. If it works it's right, if it doesn't it isn't. FWIW, I found that on modern Lionel wheelsets the distance between the inner surface of flanges (i.e., back-to-back) varies, anywhere from 1.030 to 1.050, often on the same car. This never caused me any trouble, except once or twice where there was a wide variance between the two wheelsets on a single truck.
Probably the way to go is to standardize on one size wheelset for your rolling stock and adjust your motive power if needed.
I was thinking about going the 3rail scale route and use 2 rail wheels and kadee couplers as I am just getting back into model railroading. Right now my empire consists of 2 steam engines, 2 diesels, and 20 pieces of rolling stock. It wouldn’t be a big deal to convert. I enjoy scratch building track, ugh, more to think about 🙂🙂
Jay, good idea!!! Rex, I have 2 sets of calipers, but Jay's gauge seems like it may be quicker, plus I have a mini-lathe and some tubing so I can easily make 1 or 2!
The manufacturer's MUST use something to guide them when making the wheels and trucks, otherwise we'd have more problems than we do.
I tried to build (well I actually did build) 7 #6 turnouts, but after I got a couple from Signature Switch I quickly gave up that experiment. They're on the layout, but I can surely tell when I cross one of mine and when I cross one of Brad's switches. I would rather pay the price and know that they'll work, but I did enjoy building the switches I have and may try again. I could use at least 2-3 more on the layout.
I've got 2-rail track, but still use 3-rail trucks and wheels (and battery powered RC engines for the last 4 years), no power on the rails. I told Brad this when I ordered my switches and he may have made some adjustment when he built them, but I can't tell what it is if he did.
