Restoring Atlas contacts

[Kuchler10]

I remember being told what and what not to do when it comes to attempting to restore frame-to-truck contacts for Atlas models, but I forget the recommended tools and practices to ensure the best electrical pickup. Can anyone share some tips and tricks that have worked for them? Perhaps I'm not the only N scaler out there who could use some contacts restored.

[peteski]

I polish the heck out of the tops of the metal contacts protruding from the trucks, and the surfaces on the pickup strips where by the truck touch.

On the truck side I use a 4-grit fingernail polishing stick to get the top of the metal nubs polished. For the final polishing I use a paste polish (I use Top Brite brand) and some cotton cloth.





 I remove the flat pickup springs from the chassis. Their is surface is already smooth, so there is no need to use the 4-grit sticks. I  use Top Brite on a buffing wheel in a Dremel tool to polish the surfaces which contact the truck nubs.

I think that improves the electrical contact, and the residue from polishing paste also protects the metal surfaces from oxidizing.

Also don't 'forget to service the trucks by taking them apart and cleaning and lubricating the axle points and the corresponding sideframe cup "bearings".  I use Woodland Scenics Light Oil.  Also make sure that the pickup strips contact the trucks with enough force.  Sometimes those strips are bent up or not installed properly, so they barely touch the truck contacts.

[soo]

Pete,
Excellent points you made. Have you used Flitz before, I never heard of Top Bright.
Dziękuję
Y-it

[peteski]

Pete,
Excellent points you made. Have you used Flitz before, I never heard of Top Bright.
Dziękuję
Y-it

You're welcome.
I use Top Brite because it is peddled locally here in my area.  I have heard of Flitz, but never used it.  Probably very similar type of metal polish.  Top Brite is light-tan in color and it has a slight ammonia and petroleum smell.

[MK]

Flitz is a great metal polish.  And it keeps the oxidation from coming back for a while.  A little dab is all you need.  You'll see all the oxidation end up on your polishing cloth.

[jagged ben]

Pete, does one really want oil in the cup bearings?  Does it act as a conductor or an insulator?  I keep looking to buy that 'Conducta-lube' but it's seemingly never available.   Does that mean it works?

[rodsup9000]

 

  Does it act as a conductor or an insulator?  I keep looking to buy that 'Conducta-lube' but it's seemingly never available.   Does that mean it works?

   I use a bright boy to clean on the strips and truck wipers, then a drop of Atlas conduct-a-lube on each. Then I use alcohol or mineral sprites to clean the bearing cups. On new loco's I don't disassemble the truck, but use a insulin syringe to add it.   Been doing it this way for several years now.
 It's seams to work.


 

[peteski]

Pete, does one really want oil in the cup bearings?  Does it act as a conductor or an insulator?  I keep looking to buy that 'Conducta-lube' but it's seemingly never available.   Does that mean it works?

Do you run your car or bicycle with dry (unlubricated) wheel bearings?

Those contact points absolutely need to be lubricated.  A true conductive lubricant would be beneficial, but regular lubricants will work (that is what the factory uses, and the models run).  I have not studied how those metal surfaces (bearing cup and axle point) interact on the microscopic level, since the models run, there is a metal-to-metal connection, even with the lubricant present.  Conducta-lube?  If you are talking about the lubricant sold by Atlas, is not really conductive. IIRC, the label states that it improves conductivity. Probably because the oil film protects the metal surfaces from oxidizing.  We would need a mechanical engineer to give us some lessons on how this all works (because it all does seem to work).

[rrjim1]

I use Caig Laboratories DeoxIT on all my electrical connections. I don't polish or clean just apply a very thin coating. I had two original Kato SD40s that sat in there box for a couple years and wouldn't run, I apply DeoxIT on the frame to truck contacts and that's all it took. This stuff is amazing and has made serving my n-scale fleet a whole lot easier. 

[soo]

Just visited Caig's web site,,,stuff reads to be the cure all to end all.
Probably would be handy to have when PM time comes to the fleet.
Y-it

[MK]

We use Deoxit all the time for our open frame micro servos for micro R/C airplanes.  Since they are open frame servos, they pick up all kinds of dirt and when you are dealing with control surface movements for a tiny R/C airplane, precision counts.  The stuff is a cure all for everything electrical and we have been using it long enough that we don't even question it.

Just a cautionary note.  The "red" Deoxit is the more popular one and used for metal to metal contacts.  I've used it on plastic and it's "ok" but I'm not 100% it's "Safe on Plastic".

https://caig.com/deoxit-d-series/

They make another version called Fader Lube and that is specifically safe for plastic.  I've used both and noticed not differance in either's efficacy in resolving the problems.

https://caig.com/fader-f-series/

[jagged ben]

Do you run your car or bicycle with dry (unlubricated) wheel bearings?

Those contact points absolutely need to be lubricated.  A true conductive lubricant would be beneficial, but regular lubricants will work (that is what the factory uses, and the models run).  I have not studied how those metal surfaces (bearing cup and axle point) interact on the microscopic level, since the models run, there is a metal-to-metal connection, even with the lubricant present.  Conducta-lube?  If you are talking about the lubricant sold by Atlas, is not really conductive. IIRC, the label states that it improves conductivity. Probably because the oil film protects the metal surfaces from oxidizing.  We would need a mechanical engineer to give us some lessons on how this all works (because it all does seem to work).

My car and bicycle bearings don't perform an electrical pickup function.  And the 'bearing cups' on an N scale loco don't perform a weight bearing function.  (We probably shouldn't call them that.) Not to mention the size difference.   I think that's a totally inappropriate comparison.   

I have never seen 'bearing cups' lubed from the factory, or lubed them myself, or thought it necessary.   I have seen dirt build up in the cups, necessitating a clean out, and I can't imagine that having a oil there to catch dirt is a good thing.

[rrjim1]

We use Deoxit all the time for our open frame micro servos for micro R/C airplanes.  Since they are open frame servos, they pick up all kinds of dirt and when you are dealing with control surface movements for a tiny R/C airplane, precision counts.  The stuff is a cure all for everything electrical and we have been using it long enough that we don't even question it.

Just a cautionary note.  The "red" Deoxit is the more popular one and used for metal to metal contacts.  I've used it on plastic and it's "ok" but I'm not 100% it's "Safe on Plastic".

https://caig.com/deoxit-d-series/

They make another version called Fader Lube and that is specifically safe for plastic.  I've used both and noticed not differance in either's efficacy in resolving the problems.

https://caig.com/fader-f-series/

It states right on the bottle, Save on plastics    I have used it for years and on a lot of plastics without a single problem.

[peteski]

My car and bicycle bearings don't perform an electrical pickup function.  And the 'bearing cups' on an N scale loco don't perform a weight bearing function.  (We probably shouldn't call them that.) Not to mention the size difference.   I think that's a totally inappropriate comparison.   

I have never seen 'bearing cups' lubed from the factory, or lubed them myself, or thought it necessary.   I have seen dirt build up in the cups, necessitating a clean out, and I can't imagine that having a oil there to catch dirt is a good thing.

Well then, run your dry.  I've seen globs of whitish grease applied to those bearings at the factory many times.  The contact area between the axle point and the bearing cup is so minuscule that there is probably dozens of  pounds per square inch pressure there. 

[mmagliaro]

Wait... the axle/wheel's only point of contact with the entire rest of the engine is at the two axle points.  Those axle points are supporting the entire weight of the engine, so they are indeed performing a weight-bearing function.  They are carrying the engine.  A 100g 4-axle diesel means 100g are carried on 8 points.  12.5g per point.

What's the contact area of that axle point?  Even a square mm would be generous.  12.5g/sq mm = 2550 lbs / sq ft. = 17.7 lbs/sq inch.  And remember, that actual contact area is much smaller than a sq mm, so this is a low estimate.

Yikes.  I never realized it was so high.  I'm glad I let you guys talk me out of trying to use brass axles on my 0-6-0.