Question on dirt accumulation in Kato N scale RS-2/RSC-2

[brokemoto]

Could you be a bit more specific- for example, how frequently is frequently?  Are you doing these cleanings monthly, weekly, daily?  Also, how often do you need to clean other locos in your fleet? And is this one loco, or do you have a fleet of them all exhibiting the same issue?

It seems to become a problem every six to eight weeks.  None of the other Kato power that I have has shown this problem with any frequency.  None of the power from other manufacturers has shown this problem with any frequency.  I have two Kato RS-2s and two RSC-2s.  All four of them show this problem with the regularity that I have described.




The couple things (although not necessarily Kato specific) I note in my own loco maintenance that occasionally cause dirt related issues-

I sometimes "over-lube" locos after cleaning- leading to dirt mixing with the excess lube to cause a worse problem than I had pre-cleaning.

Kato does not recommend lubricating when it is new and only lubricating if it shows binding.  Add to it that my father taught me early on that the only thing that excess lubricating does is attract more dirt.

If I run into a loco that is needing more cleaning than others, I take a look at the condition of the gears and other plastic parts in the trucks and mechanism- sometimes I find the excess "dirt" is ground plastic resulting from some parts that are not properly aligned and grinding each other down.

Thank you for the tip.  I shall check that immediately.

I just put it in Kato tender trucks.

I have seen the same problem on Kato tender trucks, but only on occasion.

I have actual silver bearing grease that is conductive. It came in a syringe the size of an ink pen.

It might be worth looking into this.  As pricey as it is, I assume that a tube of it will last a while.

I have had steam locos with those tender cone cups accumulate black crud inside the cups, killing the pickup.  I usually use a toothpick soaked in alcohol to scrap out the junk first, especially down deep at the point of the cup.  Then a small stiff paint brush, soaked in alcohol and twirled into the cup, gets rid of the rest.  I avoid putting anything sharp or metal in the cup.  It needs to remain as smooth and scratch-free as possible to avoid friction and dirt accumulation.

I've seen this on Kato Mikados, Bachmann 2-8-0's, and other engines I can't recall at the moment.
Your higher voltage theory (more arcing, more carbon build up, at high voltages) might have some merit.  I have noticed this to be more of problem on my NP W-5, which is super-geared-down, so I tend to run it more in the 10 volt and up range.

I have seen this on occasion on the Kato and B-mann tender trucks as well, but only on occasion.  I run the RS-2s/RSC-2s, Kato mikados and B-mann consolidateds at slow speeds.  Still, the spark arcing is worth considering.   

Atlas Conductalube.   It has worked wonders on my light Climax A's that live and die on pickup, and makes a NOTICEABLE improvement and a long-term benefit as well.   It has a precision needlepoint dropper so that you can get a drop into end-axle pickups, I do it as SOP now, without removing the trucks or disassembling them.

Thank you for the tip.  I will try it and see how it works.  I had a similar problem with the Atlas turntable.  There are spring loaded contact points under the rails in the actual turntable.  Crud tends to accumulate there.  I had this problem while the Big Board was still open.  One of the Atlas employees did suggest Conducta-Lube.  As I removed the turntable from my pike shortly after that, I never had the chance to try it.

The science is there though; you're putting electricity across a space, higher voltage = arcing across any gap, the spark can create carbon, which builds up everywhere as a partial insulator,

This makes sense.  Back when you actually could take spark plugs out of your engine, I used to note carbon buildup on them.

I've never had to do this to my Kato F's, just my lighter-contact units and the little 11-105 chassis are the worst.

This is my experience.  I never have seen this problem in my Kato Fs or PAs (when I still had them).  I added weight to the mikado tenders, so they showed the problem only occasionally.  The B-mann tenders already have substantial weight.  I have not seen this in my Atlas/Kato SD-7s, either.


I thank everyone for his response(s).

[peteski]

Many here know that more than once have I posted about the ten greatest ogres to all things N scale.  Eight of those are dirt and at the end, frequently I add "Did I remember to mention 'dirt'?".

One thing here is for certain: in order for the dirt or crud to accumulate in the locomotives mechanical (and electrical) parts the dirt has to be in the surrounding environment.  Period.

The wheel wipers have been used in N scale locos since the beginnings of N scwle, and more recently the needle point bearing/pickups have been used for decades.  Fact is that dirt/crud is all around us (unless your layout is encased in an airtight display case), so periodic cleaning of the locos is considered  regular maintenance.  There is nothing abnormal about that, and modelers just deal with it without much complaining. Sometimes we have a thread pop-up about what to use to clean the track, but not many complaints show up about excessive need to clean the loco's mechanical/electrical parts.

Like I mentioned, unless you are running your model trains in a clean-room, you will have to perform periodic cleaning of your locos.  If you think your locos need more frequent maintenance than everybody else's, then maybe your environment is just more dusty than average?  Or the models might be over-lubricated.

I'm the go-to loco repair/maintenance guy for my NTRAK club, and also for couple of friends with layouts, so I have seen plenty of misbehaving or dirty models.   In my experience dirty axle-point cups are not  a common problem area.  The area where the truck's sideframe pickup plate "finger" contacts the flat springy strips in the chassis, and the wheel treads are the most problematic areas.

Wheel cleaning take care of that area, and for the other area I polish both, the "finger" on the truck and the contact area on the flat springy strip.  The increases the reliability of the electrical connection.

For complete maintenance I totally disassemble the model (including the trucks) and use ultrasonic filled with Naphtha to thoroughly degrease the entire mechanism.  When I reassemble the mechanism I very sparingly lubricate all the metal parts which move. Well, except the polished contacts - I leave those dry.  I'm not sure  why you worry that repeated disassembly will weaken the plastic fasteners.  I don't  recall any of those ever failing.  The chassis halves are usually held by screws, and the trucks are made from slippery flexible plastic, so I don't think the latches will weaken after repeated disassembly.

The  worst example of mechanical wear I ever observed was on couple of Kato P42 locos my friend runs continuously on his TRAK module.  That module has couple of track loops separate from the NTRAK tracks, and my friend has trains running continuously on those loops.  The misbehaving locos have been used without any maintenance (except for wheel cleaning) for about 20 years.  When the wheel cleanings were no longer making them run better, he gave them to me for maintenance.


I found that the axle points wore holes in the axle cups.  replacing the pickup plates and a full tuneup made those locos run well again.

Dirt is all around us - as I see it, we just have to resign ourselves to that fact.

[jagged ben]

I've had problems with axle cup dirt in more than one loco and it's one of the first places I look when a loco is having problems that don't seem to be due to wheels or track. I'd been thinking of trying Conductalube for that but now Peteski has set me straight.   I guess it's fortunate it always sells out too fast!   

I suppose one could try dielectric grease in axle cups but one thing I don't like about grease is that it often attracts dirt. 

[Simon D.]

How about a soft pencil - 2B or more? Sharpened and twizzled in the axle cups or rubbed along contacts?

[Tad_T]

For complete maintenance I totally disassemble the model (including the trucks) and use ultrasonic filled with Naphtha to thoroughly degrease the entire mechanism.

Could you, please, elaborate on this process?

Thanks.

[randgust]

Well, as as a former Quality Assurance guy, I believe in scientific material testing.   Hence my fascination with tractive effort tests and documenting them.

So here's two observations:  First, if you're wearing through your axle cups (which takes a LOT of running, you need some lubrication in there.  I've had HO locomotives on our company display window layout wear like that on various pickups and moving parts, and lubrication stops it cold.)

Second, the ideal test here would be to do one truck on one locomotive with the silver contact stuff, and the other truck with Conductalube, and see what happens in those cups over time.   Not that I don't believe people, but the ultimate proof on anything is actual testing in your environment.    I just first did mine as an experiment under controlled testing, and it works for me, but I'd love to test the silver stuff too.   In our scale, electrical contact is everything.

While I won't dispute that LaBelle 108 migrates everywhere and over lubrication invites more grief than it's worth, Conductalube almost seems to evaporate, leaving some kind of film behind, but I haven't seen it produce gunk, just the opposite, I think it slows it.   But that's my result.

Another test would be to use Neolube, as that is basically just conductive graphite in alcohol.  I use it a lot on side rods, but have never put it in axle cups.   Anybody?

[ncbqguy]

I have seen the axle bearing wear problem before….but only on HO units used on layouts that received heavy use.  The HO Kato/Atlas/Stewart engines use the stub axle hole-in-the-plate pickup and wear badly although are probably less prone to gunk buildup than the enclosed cones.
In spite of that I’ve long recommended to clients that the pointed axle/coned pickup “low friction” scheme is the Gold Standard for N Scale.  Factories must feel like it is too complicated to produce as they keep reverting to various vastly inferior wipers and other pickup schemes.  The product runs fine when tested at the factory but, as documented on this board many times, fails on the layout (sometimes just due to misalignment in shipping before it goes home).   Importers should realize that it isn’t okay…customers just stop buying that brand if their product fails in use.   Kate’s fabled reputation isn’t built on having the most frequent, wide range of prototypes, and highest level of detail; it is simply having the most reliable, smoothest operation due to the solid pickups that are made from consistent quality materials.

Anything that is run on a regular basis (displays, heavy NTRAK use, regular operation sessions) should be on a regular maintenance schedule. 
Clean pickups, gears, motors and LIGHTLY lubricate….if you can see the oil/grease you applied too much!

I would agree that arcing is the cause of the gunk but that raises the question…if it is carbon, and graphite is carbon, why is it bad?   Maybe someone reading this thread has electrical or chemistry credentials that can weigh in on the discussion.  I would worry about using a pencil, no matter how soft, as you are introducing mostly clay and binders to the equation.   (Plastic wheel wear add to the gunk on track and pickup wheels but if it can migrate to inside the pickup plates has to be proven).

And I don’t know what the current (pun intended) conductive lubes have, but “back in the day” when Con-Cor was the source for LaBelle Conductalube it actually did cause shorts if you used it wrong. 

Charlie Vlk
Railroad Model Resources

[peteski]

For complete maintenance I totally disassemble the model (including the trucks) and use ultrasonic filled with Naphtha to thoroughly degrease the entire mechanism.

Could you, please, elaborate on this process?

Thanks.

There isn't really much to add.  I take the model apart, then I drop all the parts into an ultrasonic cleaner tub filled with Naphtha (keeping track where all the parts belong of course).  If the motor is really nasty (all oily with carbon powder from the brushes stuck all over its insides) I drop the entire motor in the cleaner.


Here is a photo of a fully disassembled model truck from a brass loco.  These parts have already been cleaned.  Before cleaning the parts were all oily, with  some metal shavings mixed into the lubricant.

Then I let the parts dry (I use compressed air to speed this up), then I reassemble the model, lubricating the moving parts as I go along, and polishing electrical contacts which I feel should be polished.  I mentioned polishing contact areas in my earlier post.

The ultrasonic cleaners are readily available for cleaning jewelry. Mine is an older model used for cleaning plotter pens. Naphtha is a mild solvent. It is basically Ronsonol lighter fluid, or it can be purchased in larger quantities in the paint solvents section of a hardware store as Varnish Maker's and Painter's Naphtha (or VM&P Naphtha).  It is a flammable liquid, so use caution when using it. Alcohol could be used instead, but I find that Naphtha is a better solvent for petroleum-based lubricants, and alcohol is also flammable.

[peteski]

In spite of that I’ve long recommended to clients that the pointed axle/coned pickup “low friction” scheme is the Gold Standard for N Scale.  Factories must feel like it is too complicated to produce as they keep reverting to various vastly inferior wipers and other pickup schemes. 

Too complicated? Do you think that is the real reason why come Chinese designers shy away from the "gold Standard" design?  Is it really all that more difficult to make dimples in metal sideframe plates and sharpen the axle ends?  IIRC, some Athearn models which have the axles go through a hole in the bearing/pickup plates have axles with pointy ends (that serve no function, except maybe for making assembling them easier).

Life-Like designers in China used that Gold Standard design on some of their N scale diesel locos. Atlas also uses that design in their Diesel locos which were not descendants of Kato models (so new Chinese tooling was made for those).  The parts count is about the same for both designs, and Kato version has no wires to be soldered (so less assembly time).  I'm talking about the design which has axle ends go through holes in the bearing/pickup lates. The trucks with wheel-back wipers have larger parts count than Kato and more assembly steps.

It sure is a head-scratcher as to why doesn't everybody follow the Gold Standard.

[mmagliaro]

...snip

I would agree that arcing is the cause of the gunk but that raises the question…if it is carbon, and graphite is carbon, why is it bad?

... snip

Charlie Vlk
Railroad Model Resources

Carbon is not nearly as conductive as phosphor bronze or copper. Carbon requires a lot more contact pressure to be conductive than, say, copper does.  Note how you need steady spring pressure on the graphite brushes in our little motors to maintain conductivity to the armature.  Without enough pressure, a layer of carbon is actually not conductive.
In those axle cups, when they are just clean metal on metal, they are much better conductors than when you have a layer of carbon in there. 

[Chris333]

Plus arcing is probably causing pitting on the contact surfaces making a rough ride.

[peteski]

Carbon is not nearly as conductive as phosphor bronze or copper. Carbon requires a lot more contact pressure to be conductive than, say, copper does.  Note how you need steady spring pressure on the graphite brushes in our little motors to maintain conductivity to the armature.  Without enough pressure, a layer of carbon is actually not conductive.
In those axle cups, when they are just clean metal on metal, they are much better conductors than when you have a layer of carbon in there.

Yes, carbon is nowhere as conductive as those metals. That is why large range of resistors (the electronic components) are carbon-based (either carbon film, or carbon composition).  But motor brushes are not just carbon.  They are composed of compressed blend of carbon and powdered metals. The brush spring is there to assure positive pressure with the commutator. Even if the brushes were made from slugs of copper, the motor would not run if there were no springs to press those copper slugs against the commutator.

As for the axle cups, I believe we had our resident esteemed scientist estimate the pressure between the axle and the cup. IIRC, due to very small contact area the pressure per square inch was into hundreds of pounds!  Likely high enough to displace most of the debris and remain in contact.   Of course if the track is uneven, the locos weight is not equally distributed over each axle, so there will be many times the contact pressure is lower or contact is even temporarily lost.

[Tad_T]

Could you, please, elaborate on this process?

Thanks.


There isn't really much to add.  I take the model apart, then I drop all the parts into an ultrasonic cleaner tub filled with Naphtha (keeping track where all the parts belong of course).  If the motor is really nasty (all oily with carbon powder from the brushes stuck all over its insides) I drop the entire motor in the cleaner.


Here is a photo of a fully disassembled model truck from a brass loco.  These parts have already been cleaned.  Before cleaning the parts were all oily, with  some metal shavings mixed into the lubricant.

Then I let the parts dry (I use compressed air to speed this up), then I reassemble the model, lubricating the moving parts as I go along, and polishing electrical contacts which I feel should be polished.  I mentioned polishing contact areas in my earlier post.

The ultrasonic cleaners are readily available for cleaning jewelry. Mine is an older model used for cleaning plotter pens. Naphtha is a mild solvent. It is basically Ronsonol lighter fluid, or it can be purchased in larger quantities in the paint solvents section of a hardware store as Varnish Maker's and Painter's Naphtha (or VM&P Naphtha).  It is a flammable liquid, so use caution when using it. Alcohol could be used instead, but I find that Naphtha is a better solvent for petroleum-based lubricants, and alcohol is also flammable.

I have an ultrasonic cleaner that I originally got for reloading and cleaning gun parts.

I have used it with alcohol and cleaned some frame halves from locomotives that I had purchased that were over lubricated. 

I cleaned the motors by spraying them out with CRC QD Plastic Safe Electric Contact Cleaner. It worked well.

I never have used lighter fluid in my ultrasonic cleaner though. I know that it would be safe with metal parts, I wasn’t sure about plastics.

How long do you let yours run when you clean something with naphtha?

Thanks for the reply.

[nickelplate759]

My ultrasonic cleaner (a Branson, with a stainless basin) specifically warns against using flammable solvents.    Is that just lawer-influenced caution, or are there special machines for flammable solvents?

[voldemort]

My son was working with a high tech company that does nano-silver.  For my birthday he got me a vial of the stuff.  It works.  100%.  Except that it wears off.  Its just in an acrylic binder.   

I ordered a graphite block a month ago.  With regards to conduction, if it touches both rails it immediately trips the circuit breaker.  Pretty conductive.  IDK how much the graphite will decrease pulling power of locomotives though.  Before I had this, I just used a pencil that I'd exposed the 'lead' on and ran them along the tracks.

I agree that conduction is my main problem.  I think there must be a solution out there.

I've seen videos of people with hundreds of locomotives in their basement.  I find if I haven't used a locomotive for two months, getting it going is tough.  Once a couple of laps are under its belt, its fine.  Any idea what those propulsion rich people do?