I have some older cars that need wheels. When I was at Walthers, I noticed they come in different sizes. How do you measure the wheels, and how do you know what size you need? Is it better to have plastic axles or metal?
Doug
As a rule of thumb, most freight cars take 34 inch diameter wheels, heavyweight passenger cars take 36" wheels. To measure a wheel use vernier calipers to take the size across the wheel tread. Multiply the ca;iper reading in inches by 87 to obtain the wheel diameter in HO scale inches. The run of the hobby shop wheel sets come with axles more or less the right length to fit your trucks. Metal wheels look better than plastic, they show a bright shiny metallic tread as opposed to flat black plastic. Metal axles ought to be brass, non magnetic, so they don't pull forward or backward over magnetic uncoupling ramps. Dunno what to say about plastic axles, don't remember every having any metal wheel sets that didn't have metal axles.
David Starr www.newsnorthwoods.blogspot.com
The easiest and best way to measure wheel DIAMETER (which is likely what you're talking about) is with a caliper:
They range in price from dirt cheap to more than you can afford. Happily, the former will do the job nicely. But the latter have more wonderfulocity.
You measure the tread diameter, not the overall diameter. When you multiply that number by 87 (if you're in HO), you'll get a number lie 33". Or 36". These are nominal sizes, pretty much.
Ed
Typo, Most freight cars from the transition era take 33" wheels. Modern freight cars may use 36" as well.
33" wheelsets measure approximately .382" +/- .001 in the middle of the tread (there is a slight taper).
Walthers Proto 2000 and Kadee wheelsets have plastic axles, useful if you have metal sideframes. I use Walthers Proto 2000 wheelsets and Intermountain wheelsets mostly.
I do not use plastic wheelsets. They get their axles cut and the wheels get added to scrap loads.
If you think you might be interested in scratch building in brass, get an inexpesive metal one, instead of a plastic one. You get what you pay for with precision instruments. Starrett is a trustworthy brand name. Their low end dial calipers are made in China. The next most inexpensive one is made in USA, in Athol, Massachusetts. Your buget may vary, and an inexpensive hardware store or hobby shop caliper will be more than sufficient if all you are doing is measuring wheelsets.
Before I had a dial caliper, I would assume everything used 33" wheelsets. If the couplers were low, I would swap them for 36". Too high at 36" they get 33" and fiber or brass shims.
Doug back when I started the common understanding (which as it turns out was somewhat flawed) was the 33" wheels were for freight cars and 36" wheels were "passenger car wheels." But very heavy capacity freight cars have 36" wheels, especially these days. And there were some passenger cars with 33" wheels. And to further complicate matters, some intermodal cars have even smaller wheels for clearance purposes.
But except for modern heavy cars such as 100 ton covered hoppers and such, the run of the mill boxcar or tank car or gondola likely should have 33" wheelsets.
There are more areas of potential confusion as many decades ago prototype wheels had ribbed backs and those are available in HO and other scales but are not appropriate for cars built after about the mid 1950s.
If you have a wheelset of each size and have good eyesight it is pretty evident which is which. Holding them up to a scale ruler is not always helpful because a slight tilt one way or the other can easily involve a 3" error. A dial calipers is a better way to measure.
Actually I have a jig made by Minuteman to paint the outer surfaces of wheelsets, one for 33" and one for 36" and if I found a wheel and did not know the size I'd use my paint masking jig to find out. American Model Builders makes something similar
https://www.walthers.com/wheel-paint-mask-for-kadee-r-similar-rp-25-wheels-33-quot-wheels
Most modelers feel that metal wheels are better than plastic. As far as axles go, I am not sure there are such strong feelings. In theory plastic axles might bend and thus be inaccurate in gauge but this must be pretty rare. Metal axles might be attracted to magnets that are placed between the rails for remote uncoupling of Kadee and similar couplers and I think that is why some guys prefer plastic axles. Fewer guys these days seem to use magnets in that way it seems.
Dave Nelson
Just a little caution note. Some manufacturers use different length axels. Once you have vernier calipers you can measure the length (axel point to point) so you know which axel length to buy.
Alan Jones in Sunny Queensland (Oz)
And get yourself a "Truck Tuner" from Micromark.
This little gadget cleans out and smooths the axle bearing in the trucks and helps your wheels run better.
FYI, I use Intermountain wheelsets.
It takes an iron man to play with a toy iron horse.
MisterBeasley And get yourself a "Truck Tuner" from Micromark.
And the other source is Reboxx, who I believe invented the tool.
http://www.reboxx.com/Tools.htm
One thing to remember, Kadee wheels are sintered metal wheels. Most others are machined metal wheels. Many like the machined, especially because of the shiny thread and they are a little heavier. Sintered are black thread and more capable of picking up dirt compared to machine metal. They are made of compressed powered metal and still ok. Price is lower also.
Many here have noted the cars roll better with machine metal wheels.
Don't forget the truck tuner.
For many years I used a cheap plastic dial caliper. I have a digital but it eats batteries.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Here's my two cents worth. I prefer Intermountain wheelsets and recommend the truck turner..
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
Another vote for Intermountain wheels. I use them in models with both plastic and metal trucks. Locos can pull longer trains as the rolling resistance will be decreased.
I'd certainly recommend the truck tuner, too, but wouldn't waste money changing the wheels unless there's something wrong with them.
Wayne
Many prefer metal over plastic - even though there may be nothing "wrong" with the plastic wheels. I have noted one thing wrong with plastic wheels is they tend to get a layer of gunk built up on them with running.
Rio Grande. The Action Road - Focus 1977-1983
riogrande5761I have noted one thing wrong with plastic wheels is they tend to get a layer of gunk built up on them with running.
Jim,While that is very true I have notice a thin layer of grime on some of the metal wheels on the cars I used at the club while other cars I used at the club did not have any grime.. The grime was located the wheel next to the flange. All wheels are IM 33".
BRAKIE Jim,While that is very true I have notice a thin layer of grime on some of the metal wheels on the cars I used at the club while other cars I used at the club did not have any grime.. The grime was located the wheel next to the flange. All wheels are IM 33".
The issue may not be that metal wheels don't get dirty, but a lot of folks have reported that plastic are particularly bad that way. YMMV but just thought I'd point out a common complaint - don't shoot the messenger!
riogrande5761don't shoot the messenger!
Jim,I'm not ventilating the messager..I just wanted to share a strange phenomenon I notice on some of my club cars..
Needless to say I will be scratching my head over that phenomenon for the foreseeable future.
Another thing to consider when buying metal wheels is the tread width. .087" and .088" are more prototypical in appearance, but they can be fussier when dealing with less than perfect trackwork. Kadee wheels have wider treads, but they are more forgiving, and they still give that nice "clackety-clack" sound.
Marlon
See pictures of the Clinton-Golden Valley RR
I do agree that some plastic wheels seem to collect dirt, but they're certainly not creating that dirt, merely picking it up from the track. The solution, for me at least, is to simply vacuum the track occasionally....Once a year seems plenty, although my layout is in a dedicated space which I keep fairly clean. I do clean track after ballasting or adding scenery near the tracks, operations which are usually performed at the same time. After that, the vacuuming only has sufficed for over 20 years.While some folks like the look of metal wheels, I find that they draw too much attention to their overly-wide treads (unless they're Proto-87) and the resultant overly-wide sideframes which accommodate them. I also find the racket they make annoying - not at all like the noise of a real train.The claim that metal wheels roll better is, I think, specious. The better-rolling attributes are more likely due to a more precise interface between the axle ends and the shape of the plastic "journals" in which they run.
Metal wheels do add some weight, but too much is made of "placing the weight down low". At prototypical speeds, placing the weight on the underside of a car's roof works just as well. I often do so with passenger cars, where there's little room otherwise to hide that weight Of course, there's seldom need to do so on most freight cars.
All of that being said, I do have metal wheels on about 10% of my rolling stock - most of those came that way.
It's certainly up to the individual modeller to make their own choices, so my experiences are offered here only as another possible alternative.
Way back when, I used to run just about any car with the original trucks and wheels, including the very deep flanged AHM cars. And on those plastic wheels the "gunk" - it was more than just a coating of dirt -- would build up enough on the tread to nearly eliminate the flange. Then it would eventually peel off leaving an odd circle of gunk on the ROW.
Metal wheels would get a coatint of grime or dirt but never a build-up of the stuff like that. Perhaps static electricity plays a role?
What I always assumed was that at least part of the gunk might in fact have been worn away plastic, that is, that the plastic wheels themselves were slowly but surely wearing due to contact with the (then-brass Code 100) rail and sharp curves and that the plastic "dust" that resulted was part of the wheel gunk.
I have dim (very dim) memories of an article in MR where they actually sent car wheel gunk in for a genuine chemical or spectographic analysis to try to answer the age old question, just what IS this stuff? I no longer recall the results and whether micro bits of plastic made up the gunk. I suspect oil and lubricant and household dust were ingredients however.
doctorwayne I do agree that some plastic wheels seem to collect dirt, but they're certainly not creating that dirt, merely picking it up from the track.
I do agree that some plastic wheels seem to collect dirt, but they're certainly not creating that dirt, merely picking it up from the track.
Thats what I noticed when I used to run trains in my garage layout; basically all of my rolling stock had plastic wheels back then and they would get quite a thick layer of gunk on them. Of course a grage layout is subject by it's environment to more dust etc. I had no other place at that time. I do clean track after ballasting or adding scenery near the tracks, operations which are usually performed at the same time. After that, the vacuuming only has sufficed for over 20 years.
While some folks like the look of metal wheels, I find that they draw too much attention to their overly-wide treads (unless they're Proto-87) and the resultant overly-wide sideframes which accommodate them. I also find the racket they make annoying - not at all like the noise of a real train.The claim that metal wheels roll better is, I think, specious. The better-rolling attributes are more likely due to a more precise interface between the axle ends and the shape of the plastic "journals" in which they run. Metal wheels do add some weight, but too much is made of "placing the weight down low". At prototypical speeds, placing the weight on the underside of a car's roof works just as well. I often do so with passenger cars, where there's little room otherwise to hide that weight Of course, there's seldom need to do so on most freight cars. It's certainly up to the individual modeller to make their own choices, so my experiences are offered here only as another possible alternative. Wayne
It seems most of the manufacturers have decided that metal wheels are better or that most customers want them; Athearn, Athearn Genesis, Intermountain, ExactRail, Moloco, Tanget, Atlas all come with them now. I have found in general, most experienced model railroaders these days prefer them too. Just an observation to throw out to the rebels!
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riogrande5761....It seems most of the manufacturers have decided that metal wheels are better or that most customers want them; Athearn, Athearn Genesis, Intermountain, ExactRail, Moloco, Tanget, Atlas all come with them now. I have found in general, most experienced model railroaders these days prefer them too. Just an observation to throw out to the rebels!
I certainly agree that that's the situation, and most of the metal-wheeled equipment which I'm running came that way. It is, of course, part of the reason that most of today's models cost more than a similar car in the past, but that simply obviates the need for the purchaser to install after-market wheelsets. For me, I consider it an added expense, but one that's unavoidable if I want that particular offering.I've also fitted some scratchbuilt cars (or used cars bought without trucks) with aftermarket trucks, especially those from Tahoe Model Works. In many cases, I'm more interested in the style of the sideframes than in whether or not the wheels are metal.I do wonder, though, when I often see photos of nicely done models on equally nicely-done layouts, but the wheels are still shiny bare metal. Most prototype wheels are delivered with a coating of surface rust - I see lots of them around here coming from the factories where they're made. Once installed, the treads are quickly worn shiney again, but the sides (front and back) along with the axles, will normally remain rusty-looking and will then begin to accumulate dirt. It's none of my business if anybody wants to run metal wheels on everything, but please, give them some paint to make them look as real as everything else in those photos. (Removing that shine would make it easier on my old eyes, too, when viewing the photos. )A freight car can be done, using a brush, in five minutes or less, wheel faces front and rear, and axles, with no need to remove the wheels from the trucks or the trucks from the car. In fact, if you're replacing plastic wheels with metal ones, it's easier to paint them once they're installed in the trucks.
Rebel? Naw, like everybody else here, I simply like what works for me, but do appreciate seeing others' ideas and suggestions, and am not opposed to adopting (or adapting) those which suit my needs. In the same vein, I simply offer my observations and experiences for others to use or ignore as they choose. I've never considered my way to be the way, only one of the many possibilities available.
Good topic. I've been cleaning gunk off of plastic wheels for almost 40 years...
trainmasterg ...I've been cleaning gunk off of plastic wheels for almost 40 years...
Yeah, I've had to clean some plastic wheels on used cars which I've bought, but not on ones bought new, even though some of the latter have been in service for more than 35 years. I did have a problem with Kadee's metal wheels on my cabooses collecting a lot of crud on their treads - to the point that some wheels appeared to be flangeless. Those wheels were used as-bought. I used the tip of a small screwdriver to clean the treads, then polished them using a wire wheel in my Dremel. This removed the chemical blackener from the treads, too, and seems to have corrected the dirt collecting problem.Much of my passenger equipment is Rivarossi heavyweights, and all of those are equipped with Kadee 36" wheelsets. They don't get run as often as the cabooses, but I made a point of cleaning the blackening off all those wheeltreads simply as a pre-emptive measure.
No one has mentioned the axle to sideframe interface. Our roll standard is that a car must roll, from a dead stop, down a 2 percent slope. Our layout has several long grades of about 1.75-2 percent and almost constant curvature. Good-rolling cars are very important. When we started testing cars, our initial failure rate was about 30 percent.
In examining and roll-testing a fleet of several hundred cars, we have found that the most consistent passing performance is from cars that have a metal axle and a plastic truck sideframe. (The number of cars with a metal sideframe and plastic axles is very tiny).
Cars with plastic to plastic tend to become "sticky" after several months of use. This can be fixed by careful cleaning but the car will become sticky again after several months. In some cases, the shiny finish wears off the axle tip and the wheelset is replaced -- usually by one with a metal axle. We use Intermountain, Tangent, Exactrail, NWSL and Reboxx sets, in roughly that order.
We have very few, if any, cars with plastic wheels, but a friend with a 20x15 home layout that was frequently operated found his track cleaning need was greatly reduced after converting his cars to metal wheels.
Graham LineNo one has mentioned the axle to sideframe interface....
Actually, I mentioned it several posts ago. While the materials would certainly have some "bearing" on the rolling qualities, I think that the shape of the axle ends in relation to that of the journal openings comes into play, too.The first trucks with plastic wheels on needlepoint steel axles, running in sideframes made of engineering plastic, were a quantum leap in rolling performance over the older blunt-end steel axles in cast metal sideframes. I'd guess that tolerances on current-day trucks would be improved even further, another reason why axle length needs to be considered carefully when changing out wheelsets, plastic or metal wheels notwithstanding.Wayne
Medina1128 Another thing to consider when buying metal wheels is the tread width. .087" and .088" are more prototypical in appearance, but they can be fussier when dealing with less than perfect trackwork. Kadee wheels have wider treads, but they are more forgiving, and they still give that nice "clackety-clack" sound.
Kadee offers HO wheels in both .088" and .110" widths.