Some say the plastic wheels, being non-conductive, develop more low
level static discharge and therefore attract the dirt. We've heard
people say that metal wheels cut down on crud a lot. Some of my RR has
metal wheels but many cars do not because they are not really worth
changing. The track gets dirty regardless of which type I use.
By running a track cleaner car frequently (and keeping the wheels
clean), I haven't had MAJOR problems with plastic wheels. In fact, if
you clean frequently (recommended), I can't tell for sure if plastic are
dirtier than metals.
Pick up one car of each type and look at the wheels.
However, since you clean the track frequently, you might not see a
I changed to metal wheels a while ago, and the difference was very
noticable. The sound of hte train improved as well as the rolling qualities
of the cars.
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I totally agree with you Frank, those metal wheels make a really
nice "clack-clack-a-clack" when they run over a diamond or frog. I used to
get sooooooo much crap build up on plastic wheels that at times you almost
couldn't see the flange.
ALL wheels pick up SOME dirt. My experience, too, has been that plastic
wheels pick up MORE dirt. I don't know why this is so, but I doubt the
idea that static has much to do with it.
To generate static by friction one normally needs friction between two
(relatively) non conducting items (plastic, rubber, cloth, fur, etc.).
The wheel is effectively grounded to the metal rail. Also, the dirt that
builds up on a wheel usually has a substantial metal content (from worn
track and metal wheels), and would likely be conductive enough to
further ground the wheel. Static electricity has high voltage but
usually next to NO current delivery capability ... even materials with
very high resistance will effectively ground it. Even AIR grounds it,
especially moist air.
I could see plastic axles turning in plastic sideframes as a possible
source of static, but, if so, then our plastic trucks would be
collecting lots of dust and 'growing hair'in addition to the wheels. I
don't see this happening.
I think the wheels just roll up dirt off the track. This dirt is mostly
just settled dust, with a little dropped oil, and worn metal and plastic
dust from the track and the wheels themselves. There's just enough
moisture or oily residue to cause it to stick together, and imbed into
or adhere to the wheel tread. My guess is that the softer plastic wheels
are more prone to microscopic imbedding. Despite the light weight of our
model cars, the actual contact pressure at the point where the wheels
touch the rail is considerable (very small contact patch). Each wheel
acts like a miniature laminating press, and rolls it's own 'dirt tire'.
If you want to find out if static is your problem try using some of that
anti static spray to clean the wheels... it should be obvious when the
dirt just falls off when you spray it...try monitor cleaner too...I
believe that has antistatic stuff in it too!
And if you don't think static builds up without friction... static is
the accumulation of excess electrons (or electron holes) and there has
to be more than one way to do that.
I think most cars have metal axles and plastic sideframes/wheels.
Accurail has a plastic wheelset though, because it's all one molded
piece (and they really roll bad too...they were the first reason I went
to replacement wheelsets)
But many, MANY people use Kadee or P2K wheelsets in Athearn (or similar)
sideframes. That's plastic on plastic. It causes wear and friction
problems over time, but I've NOT seen it produce static (though in
principal it could).
A few otherwise decent kits come with all plastic trucks, and Life Like
(not P1K or P2k), Bachmann, and several other low-end train set models
use, or have used, all plastic trucks commonly.
I'd suspect that the dirt embeds itself into the plastic easier than the
Actually, I've seen times that metal wheels have collected dirt faster than
plastic wheels do. It all depends upon the type of dirt that you are dealing
Why isn't there an Ozone Hole at the NORTH Pole?
No doubt that's true. The type of dirt encountered is an 'environmental
issue', and depends on the location.
What I get tends to be dust (mini fibers), grit (mineral?), oil,
metallic dust, paint chips, and 'who knows what'. I suspect all manner
of condensed vapors (paint, solvents, cleaning materials, outgassing
plastics, etc.) also contribute. Particles of graphite from Kadee
'grease-em' shed from coupler pockets is likely also there.
We once used kerosene heaters in the building where our club layout is
displayed at Christmas. It could get COLD 'back then' ... -10F degrees
and 40 mph winds. WE were in a 'historic' building .. read: NO storm
windows, NO insulation, free outside air flow beneath the floor. etc.
FUN! Once we had FIVE such heaters going, and still had SNOW on the
floor! The kerosene fumes condensed on the track something awful, like
varnish. We had to clean the track about once an hour to get even barely
If allowed to build up, the wheel 'gunk' rolls itself into 'tires' on
the wheels. While a brittle material by nature, with care these can
sometimes be chipped off in big curved segments. They often have a
metallic sheen from the imbedded metal or graphite particles. I haven't
tested it, but I suspect it's partially conductive (not enough to cause
shorts, but maybe ground static).
I lean to the idea that plastic wheels are somehow more porous to attract
and hold the crud. I'm surprised no one has mentioned the difference in
metal wheels. Old Athearn compressed metal powder Diesel wheels are
notorious for attracting crud as compared with NWSL machined solid metal
replacements. I think the same is true with Lionel wheels - the sintered
metal powder wheels used on postwar rolling stock seem to collect more black
adherent crud than prewar pressed steel sheet metal wheels or "new Lionel"
cast zinc alloy wheels (although this could be related to the fact postwar
Lionel ran so much better (reliably and thus longer) than the prewar trains
or many of the "new Lionel" offerings. Gary Q
The sintered ("grindstone" texture) wheels as used on Athearn locos,
give an unusually high factor of adhesion (traction), and wear well.
Their affinity for dirt and poor electrical contact more than
compensates for these virtues. They are, as you say, especially good at
collecting dirt, and are indeed porous, which may well explain the
Plastic wheels, on the other hand, are not particularly porous, yet they
still collect dirt. It may be that the softer (compared to metal)
plastic just allows dirt to imbed into it's surface more easily. Or,
perhaps it gets (microscopically) scratched more easily, leaving pockets
for the dirt to collect into. As I've stated, I don't think static has
much to do with it, though it can't be ruled out entirely as a contributor.
And, as others have observed, it also depends on the nature of the
'dirt' in your layout room. Some even report more dirt on metal wheels,
but that's sure NOT been my observation.
Acually, plastic is porous, at a microscopic level. This is why plastic
cutting boards need regular dousing with bleach -- they provide good
hiding places for kitchen bacteria, better than wood. Also, all plastics
are "filled" with additional compounds to increase wearability,
hardness, rigidity, etc. In effect, plastics are alloys. This means that
at the surface there wil be different substances exposed to the crud on
the rails, and some of these will simply pick it up easier. Some stuff
just sticks more easily to other stuff, is all.
At any rate, that's how I explain it.
True, but your description also applies to many metal wheels. Brass and
Nickel-Silver are both alloys (mixtures of two or more materials), have
a highly variable grain structure, and frequent microscopic voids. The
sintered metal wheels are HIGHLY porous. Plating, too, can be very rough
to start with, and frequently wears through, leaving an even rougher
Since several different plastics are in common use in model railroading
(Styrene, ABS, Polycarbonate, and Acetal, at least), and the quality of
both the 'mix' and molding technique likely vary a lot, most anything is
possible. Some plastics have low porosity, and make excellent moisture
barriers. Others, like Nylon, are quite porous and actually soak up
water like a sponge.
A smoothy TURNED fine-grained solid metal wheel is undoubtedly harder
and less porous than many plastic wheels. I suspect this has a lot to do
with their resistance to 'gunk' build up.
Agreed. Plus they have a higher coefficient of friction than
nickel-silver or brass (more T.E.), and wear longer. I've made a few
such tires as replacements, and been very satisfied with the result. I
wish more manufacturers would use SS loco (at least) tires.
The downside is that most stainless steels are hard to machine without
proper technique, and don't machine easily on small non-rigid
hobby-sized machines. It's do-able, but more care and technique must be
used, compared to brass or NS. The 'trick' to working stainless is to
use VERY sharp tools, and cut aggressively. You need to cut deep enough
to get under the metal's hardened 'skin', and once you get a cut going,
DON'T stop until you're finished. If you let the tool 'skate' on the
metal surface, the SS will work harden, and it'll be VERY difficult to
get the cut going again. The idea is to peel off the metal as fast as it
work hardens, so the tool is always working on fresh metal. An
adequately aggressive cut can be hard to maintain with 'flexible' and
low powered machines. Such factors are not much of a issue with
industrial grade machinery, though proper technique is still needed.
On Wed, 16 Feb 2005 10:01:32 -0500, "Daniel A. Mitchell"
Who supplies driving wheels with stainless steel tyres? and at what
All the claimed benefits are obtained with mild steel tyres which are
readily available in a huge range of sizes and have been proven on
thousands of locos. I have some in service which have been in use for
over 35 years now and do everything mentioned above.
See <http://www.scalefour.org/ag/ag4.htm#Wheels or
Make friends in the hobby.
Garratt photos for the big steam lovers.
I disagree with Mikes assessment about the coefficient of friction for
stainless steel and oily nickel silver track. My measurements put it at
about the same as nickel plated wheels, which is less than the softer
materials. However I still can run full prototype length trains.
RTR brass models from Asia come with stainless steel wheels. It costs about
double to machine stainless steel compared to brass. That's why
manufacturers have generally avoided using it.
The only problem with mild steel is it rusts, and if rusty electrical pickup
is poor. The fact is in my local environment, Sydney Australia, steel rusts
quickly and would be a maintenance nightmare. Not a problem with stainless
steel wheels, which I have been using for about 20 years without any rust.
It's interesting that only some UK manufacturers make mild steel wheels,
with Sharman wheels offering nickel silver tyres as the more expensive
option. Nickel silver also does not rust, is good for pickup. It's my
second choice for driving wheels, I have NWSL Nickel Silver wheels on some
of my diesel locomotives, where the wheels are mostly hidden, and colour of
the wheel tread is not as obvious. Much better than blackened brass or
nickel plated brass which after some running wears back to dirt attracting
Like I said, in 35 years this has never been a problem, including when
I lived in Sydney.
Then you have another 15 years to go before they are shown to equal my
mild steel ones.
The two suppliers with the biggest range use steel for most of their
range, the other suppliers cater for those who believe the anti-steel
views frequently expressed by those who have never actually tried it.
Can you support that? Nothing about such an option on their website
and I have never been offered a choice when buying them. They do use
nickel silver for their 3mm scale wheels which are done at the 3mm
It oxidises which is pretty much the same thing!
Its my second choice to, still need the odd wheel that is not
available in steel.
At least we seem to agree that brass is unsuitable for wheel tyres.
Make friends in the hobby.
Garratt photos for the big steam lovers.
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