MT Metal Wheels

[mmagliaro]

Bill,

That photo is fine.  It gets your point across.  No, nothing like that is happening on the 12 I have.  Yours clearly have silver spots where the blackened layer has flaked off.

The thing about blackening solutions is that they really just oxidize a top layer of the metal.  If you over-do it, that oxidized layer becomes very flakey and brittle and will come off like that.  That's happened to me when I've just blackened things at home.  Maybe some of the wheels were treated too long in the blackening "bath" (assuming these were chemically blackened, and it sure looks like they were).

[peteski]

Why didn't MTL just reissue their original wheels and axles?  Maybe I am dating myself, but, in 1968 and for a few years after, all Kadee MT cars had metal wheels with plastic axles.  You had to check the gauge and adjust as necessary.  I remember that these wheels had a swirl design on the inside.  later, Craig

You are right about those original wheels. The problem was that those were blackened white-metal castings. White-metal has a rough surface and attracts dirt and dust.  Nowadays metal wheels are machine-turned out of brass or nickel-silver.  Those have much smoother tread surface and do not collect dirt as much as the white-metal wheels.  But if the new MTL metal wheels are also cast from white-metal then I would agree with you - just make new molds with NMRA-spec dimensions to get rid of the pizza-cutter flanges.

I ordered a set of these wheels on Saturday - I'm also curious as to that they look like and what material they sued for the wheels.

[Maletrain]

For me, the attaction to metal wheels is two-fold: less rolling friction and less crud on the rails. The down-side is more potential for short-circuits at gapped rail joints. 

Rough wheel rolling surfaces negates the rolling friction advantage, and any sort of chemical treatment "stuff" wearing off treads seems like it would make for more crud on the rails.

So, I am interested in how these new wheels tend to actually perform in-service on layouts.  Any experiences there, yet?

[mmagliaro]

Okay, I've done some tests and observations.

I started wth a stock 40' Micro Trains freight car with MT low-pro plastic stock wheelsets in it.

Free-spinning test:

Observing the car on its back in a cradle with each of MT, MT metal (hereafter called "MTM"), and Fox Valley (FVM),
the MTM wheelsets definitely free-spin a little longer than MT of FVM .  The FVM wheelsets free-spin about the same at
MT wheelsets, BUT (and this is a big BUT), there is significant variability in the FVM wheelsets!  I had not really noticed this before, but even though two FVM wheelsets may measure across the points at 0.540", some definitely spin in the trucks better than others.   Even looking at them with optivisors, it's not obvious why, except that sometimes the points on the tips of the axles appear to be not quite as perfect as on others.  This also seems to cause a slight wobble in the rotation of the wheelset and it is noticeable on the track as a sort of throbbing/pulsating sound as the car rolls down a hill.

So, I was careful to get 4 "good" FVM wheelsets for this trial.  But this is something to be wary of in the future with these wheelsets.  I use them a lot, so I may revisit some of my cars to see if this has been causing me unneeded drag.

Track Hill Test:
I chose a section of curved hill about 30" long, started the car at the top and let it roll.  I did multiple trials so that I could eliminate any inadvertent effects of how I happen to release the car with my hand.

The MTM wheelsets did  1 car length longer roll than the stock MT wheelsets.   That's 3" on a 30" run, about 10%.

The FVM wheelsets did a solid 2 car lengths longer.  That's 6" on a 30" run, about 20%.

====================================

This was not what I expected.  I was sure the FVM wheelsets would be the shortest roll.  I strongly suspect that my belief that FVM wheelsets induce more drag in a train has been caused by some of these "bum" wheelsets.  In fact, when I first did this trial, the FVM case had a shorter roll, but I noticed that pulsating sound, found the slightly-imperfect wheelset, and changed it out.

The big, and pleasant, result was that even though individual MT metal wheelsets sound noiser individually when I roll them on the rails with my fingers, in a car it is a completely different story.  They were extremely quiet.  I would judge them more quiet than FVM wheels.  It could be just the added pressure from finger-rolling that caused me to hear extra noise.  It could also be that the all-plastic axles dampen any sound through the plastic sideframes.

The other nice result was that the MT metal wheels rolled a little further than stock MT plastic wheels.

Of course, just because a car rolls 10% or 20% further down a hill does not mean your train will be able to pull 10% or 20% more with different wheelsets.  All this test does is give us a comparative feel for which wheelsets roll more freely than others.

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So overall, even though I really had doubts about these at first, my impression of the MT metal wheelsets is very positive.  They roll quiet, they spin more freely than the stock plastic wheelsets, they are dead-on in gauge on an NMRA plate.

Other info:
They are not "sort of" conductive.  Pressing meter leads on the tread, you have to press and fiddle to get a complete circuit.  This means the meter probes probably touch a lucky spot where the blackening isn't quite are thorough.  All this means is that you can't count on these wheels for pickup, nor can you count on them being insulated.  Best to treat them as conductive for the purpose of  being careful to avoid a potential short circuit, but not count on them for electrical pickup.  Of course, the plastic axle guarantees that you'll never have a short across the wheels.  The only possible short would be a single wheel doing something like short through a switch point.

Which leads to... These are definitely "wide tread" wheelsets.  The treads are wider than the standard FVM wheel (but narrower than standard MT plastic wheelsets).  That may be a plus or a minus, depending on what you like on your rolling stock.

Measured on a caliper, I get:
                Flange width    Tread Width
MT                 .010"                .052"

MTM              .028"                .048"   

FVM              .020"                .040"

The NMRA spec says the flange width maximum is .020", so the MTM are wide there.

The flange depth of the MT metal is .020" vs FVM .015".  Personally, I like this.  It will not make one bit of difference to me visually, it is still plenty of clearance over code 55 ties,  and that extra .005" can be very helpful on less-than-perfect trackwork.

The MT metal are definitely non-magnetic.  I tested them with a magnet.

[peteski]

Okay, I've done some tests and observations.

I started wth a stock 40' Micro Trains freight car with MT low-pro plastic stock wheelsets in it.

Free-spinning test:

Observing the car on its back in a cradle with each of MT, MT metal (hereafter called "MTM"), and Fox Valley (FVM),
the MTM wheelsets definitely free-spin a little longer than MT of FVM .  The FVM wheelsets free-spin about the same at
MT wheelsets, BUT (and this is a big BUT), there is significant variability in the FVM wheelsets!  I had not really noticed this before, but even though two FVM wheelsets may measure across the points at 0.540", some definitely spin in the trucks better than others.   Even looking at them with optivisors, it's not obvious why, except that sometimes the points on the tips of the axles appear to be not quite as perfect as on others.  This also seems to cause a slight wobble in the rotation of the wheelset and it is noticeable on the track as a sort of throbbing/pulsating sound as the car rolls down a hill.

Thanks Max!  Remember for the free spinning test, besides the friction of the bearing ends the big difference is that due to mass, the metal wheels will exhibit much more pronounced flywheel effect than plastic wheels.  So even if friction at the bearings was identical, they will spin longer than plastic wheels.

[C855B]

I was waiting for your results before saying anything. I ran a similar test five or six years ago comparing MT to FVM, and the results were nearly the same, where FVM bested MT by 15-20% consistently.

The FVM variability may be due to manhandling of the truck frames. I discovered distorting the truck frame too much during removal of the MT and pressing in the FVM was contributing to inconsistency. If an FVM truck ran "too short", I pulled it apart and spread the frame a little. It helped immensely.

[mmagliaro]

Thanks Max!  Remember for the free spinning test, besides the friction of the bearing ends the big difference is that due to mass, the metal wheels will exhibit much more pronounced flywheel effect than plastic wheels.  So even if friction at the bearings was identical, they will spin longer than plastic wheels.

Absolutely true.  My "free spinning" test was mostly just to make sure that they rode really loosey goosey in those sideframes.  It isn't a quantitative test of any kind.  I must say, these wheels work really well - a lot better than I thought when I saw the rough looking tread surfaces.   Now... one big test that needs to be done is a tracking test of some kind.  That's a hard one.  Since nobody is likely to have a trackwork "slolam" to challenge a wheelset and score it, we will have to rely on anecdotal experiments of people just trying these out and running the for a while to see how they do visa vis derailments.

[nkalanaga]

I'd be worried about the wide flanges.  Especially in my dual gauge track, my flangeways tend to be right at the NMRA width, simply because there wasn't room for anything wider.  These sound like they wouldn't fit.

[Point353]

Okay, I've done some tests and observations.

So, I was careful to get 4 "good" FVM wheelsets for this trial.
Track Hill Test:
I chose a section of curved hill about 30" long, started the car at the top and let it roll.  I did multiple trials so that I could eliminate any inadvertent effects of how I happen to release the car with my hand.

The MTM wheelsets did  1 car length longer roll than the stock MT wheelsets.   That's 3" on a 30" run, about 10%.

The FVM wheelsets did a solid 2 car lengths longer.  That's 6" on a 30" run, about 20%.

So, the car with the "cherry picked" FVM wheelsets outperformed the cars with the MT/MTM wheelsets.
How much worse would the performance be for a car equipped with randomly selected FVM wheelsets?

[Maletrain]

Now... one big test that needs to be done is a tracking test of some kind.  That's a hard one.  Since nobody is likely to have a trackwork "slolam" to challenge a wheelset and score it, we will have to rely on anecdotal experiments of people just trying these out and running the for a while to see how they do visa vis derailments.

I suggest a #6 double crossover for the tracking test.  It provides the "S"-curve, plus turnout points and frogs in the turnouts and diamond.  And, it is pretty standard so long as the same frog number is used.  It would be very standard if the same manufacturer's double crossover was used by everybody.

And, thanks for the test info.  I am still working on getting room for my layout, and have trouble getting even space for a test rig.  So, info like you provided in really useful to me. 

In the future, I intend to have a rig with an adjustable angle for a 30" piece of Atlas 55 track, with a bubble level to make sure I start from flat, and a way to measure grade to tenths of a percent.  Then I can make sure that each of my pieces of rolliing stock meet the same (yet to be established) standard for free-rolling friction. 

But, even letting different cars roll down the same grade requires some accounting for the different weights of the various cars and some math to figure-out the actual friction force retarding each car.  Having standard weight cars would help, but different car lengths have diffrent standard weights, so the weight consideration is not totally avoidable.

[mmagliaro]

So, the car with the "cherry picked" FVM wheelsets outperformed the cars with the MT/MTM wheelsets.
How much worse would the performance be for a car equipped with randomly selected FVM wheelsets?

That's impossible to know.  I don't know how common it is to have a bad FVM wheelset that isn't obviously damaged, yet doesn't spin freely in the sideframes.

BTW: I've heard mention of bending the sideframes outward to free up the FVM wheels before.  But that was not the case here.  The wheel wasn't binding.  It had a slight defect in it's axle points that was causing it to wobble a little at the very tip.  It was not visually noticeable on the track.  The car wasn't vibrating or wobbling up and down.  It just didn't roll as smooth as it should have, and made a weird little pulsing noise.  If you had a car like this in a 20-car train, I doubt you'd notice it.  So that's why I wonder how many of my converted cars have slight rolling problems like this.

At least now I have a metric.  I can test-roll each car on that same stretch of hill and pull any obvious bad performers out of the fleet to check their wheels.  (and lucky for me, I only have about 50 converted cars, not hundreds or thousands).

Word to the wise.  Check every car you convert, individually, against some rolling standard before you put it into your roster.

[Point353]

That's impossible to know.  I don't know how common it is to have a bad FVM wheelset that isn't obviously damaged, yet doesn't spin freely in the sideframes.

Can you simply repeat your test using a car equipped with some FVM wheelsets that were randomly selected from among those you have on hand, rather than culled to find "good" ones?
 

[robert3985]

Can you simply repeat your test using a car equipped with some FVM wheelsets that were randomly selected from among those you have on hand, rather than culled to find "good" ones?
 

@Point353

When I replace my old wheelsets I check to make sure that the new metal wheelsets that are replacing the old wheelsets don't have any obvious functional flaws, no matter what brand they are.  I don't wear a blindfold when doing this job.

After I've inserted the new wheelsets, I paint 'em, then do a little test-roll on the layout through a couple of my tight-NMRA standard hand-laid, C40 turnouts down at Echo Yard to make sure they'll function flawlessly on the rest of my layout.

So, I check each and every car at least once before allowing it to run regularly on my layout, and at least twice if I've replaced its original wheelsets.

I do something similar with each and every engine that I allow on my layout too.  Before I even set a new engine on the tracks, I check the gauge on its wheelsets because cars and engines must be perfectly gauged to run smoothly through my "tight-NMRA" hand-laid turnouts. The only engines I've ever checked that didn't need adjustment are my Kato FEF's, which were perfectly gauged out of the box...but I still check 'em when I get a new one.

The point being, always check your cars and engines to ensure they will not cause problems on your layout, just like Max has already admonished us to do when he posted directly before you when he wrote this: "Check every car you convert, individually, against some rolling standard before you put it into your roster."

As for me, I'll continue to use FVM wheelsets exclusively because they are machined and because of their bright, narrow tires and their more prototypical looking wheelfaces, even if there is an occasional bad one in the package.

Cheerio!
Bob Gilmore

[Point353]

When I replace my old wheelsets I check to make sure that the new metal wheelsets that are replacing the old wheelsets don't have any obvious functional flaws, no matter what brand they are.  I don't wear a blindfold when doing this job.

So, I check each and every car at least once before allowing it to run regularly on my layout, and at least twice if I've replaced its original wheelsets.

I do something similar with each and every engine that I allow on my layout too.  Before I even set a new engine on the tracks, I check the gauge on its wheelsets because cars and engines must be perfectly gauged to run smoothly through my "tight-NMRA" hand-laid turnouts. The only engines I've ever checked that didn't need adjustment are my Kato FEF's, which were perfectly gauged out of the box...but I still check 'em when I get a new one.

The point being, always check your cars and engines to ensure they will not cause problems on your layout, just like Max has already admonished us to do when he posted directly before you when he wrote this: "Check every car you convert, individually, against some rolling standard before you put it into your roster."

I'm trying to get some sense what percentage of the FVM wheels are "good" right out of the package or how many need some sort of adjustment before they're usable.

The vast majority of my rolling stock rides on MTL plastic wheels and I haven't found much need to pre-screen them for acceptability before putting them on the layout.

The advisability of verifying the gauge of loco wheelsets is a given, however.

[Mark5]

Why didn't MTL just reissue their original wheels and axles?  Maybe I am dating myself, but, in 1968 and for a few years after, all Kadee MT cars had metal wheels with plastic axles.  You had to check the gauge and adjust as necessary.  I remember that these wheels had a swirl design on the inside.  later, Craig

Decisions, decisions ... 



(recent run Athearn on left, ancient Kadee Microtrains on the right)

Mark