Atlas/Kato RSD12 resurrection

[nickelplate759]

I'm resurrecting an old Atlas/Kato RSD12.   Yes, I know it's a Franken-loco (short wheelbase, short long hood, incorrect DB vents, lightweight trucks, etc.), but until I get worked up enough to kitbash a proper one it's all I've got.  It was also the first factory-painted NKP diesel I ever got.

I've added DCC, including Gyra-Lite.  I used a TCS M4, but if I ever do it again I'll use a CN-GP.

The mechanism is old, obviously, and suffers from flaky contact.   Does anyone have any tips for tuning it up?  I don't want to replace the mechanism - I'll do that if I ever kitbash a proper RSD12.

[central.vermont]

George,
one thing that I did to an RS11 (same chassis) was to polish the area where the truck makes contact with the chassis as well as the top of the truck where it makes contact with the chassis.  This helped a lot for me.

Jon

[central.vermont]

One other thing that you can also do is to use a new chassis. Probably not what you may want to do with what you have invested already but it is an option.

Jon

[Freight Train]

I've been tuning up a couple of Kato/Concor Sw1500 mechanisms and how they conduct electricity from the trucks through the body is similar to the RSD-12. What I've doing where metal meets metal from truck to body is to clean those areas and apply conduct lube. The lube helps to prevent metal corrosion and helps to promote conductivity between the trucks and the frame. Also, any where inside the trucks where metal meets metal clean well with alcohol. I don't recall of the RSD-12 trucks have the bronze wiper on one side of the truck as the SW 1500 but clean these areas too well with alcohol. Sure wish someone would do a correct RSD-12. My first one too was a NKP. 😉

[nkalanaga]

As the other said, polish the contact areas.  If you're comfortable with drilling trucks, you could drill the metal frames, and the loco frame, press brass rods into the holes, and solder very fine wire between the trucks and the loco. 

I know, wires are old-fashioned, but they also conduct a lot more reliably than sliding oxidized zinc alloy contacts.

[nickelplate759]

Adding wires isn't crazy to me.  If polishing isn't good enough I just might do it.

In other news, traction of this model was never very good, so I've managed to add nearly 1/2 oz. of lead sheet inside the roof of the shell.  I could have added a little more if I had use a CN-GP instead of the M4 decoder. 

[peteski]

I've managed to add nearly 1/2 oz. of lead sheet inside the roof of the shell.  I could have added a little more if I had use a CN-GP instead of the M4 decoder.

That by itself should improve electric pickup, but the  burninshing/polishing of the contact areas between the truck and frame will also make a big difference.

[mecgp7]

 I play with these old Kato made chassis all the time and can get them to run almost as good as the newer flywheel version.
In addition to above:
1. Replace the wheeles with traction tires
2. Remove the bronze wipers in the trucks
3. Clean the axles of the trucks
4. File and burnish the "U" shaped areas that accept the axles
5. Clean the inside of the frames and motor contacts
6. Add some sort of anti-oxidant to the contact areas
5. Clean wheels

They run great after this surgery.

[peteski]

I play with these old Kato made chassis all the time and can get them to run almost as good as the newer flywheel version.
In addition to above:
2. Remove the bronze wipers in the trucks

They run great after this surgery.

What does that do to improve electrical contact?  On my models I usually bent them out further to put more pressure on the contacts.  I thought that would make a more reliable contact of the wheels and metal frames

[nickelplate759]

What does that do to improve electrical contact?  On my models I usually bent them out further to put more pressure on the contacts.  I thought that would make a more reliable contact of the wheels and metal frames

Pretty sure nothing, because these particular models don't have any bronze contacts.   

Polishing the truck-to-chassis contact points did help.   For "conductive lubricant", what do folks recommend? Something I can get at the hardware store hopefully?

[peteski]

Pretty sure nothing, because these particular models don't have any bronze contacts.   

Polishing the truck-to-chassis contact points did help.   For "conductive lubricant", what do folks recommend? Something I can get at the hardware store hopefully?

There is no real conductive hobby lubricant.  This is often mentioned misnomer. Yes, there are trye electrically conductive lubricants which use powdered metal (such as nickel or silver) mixed with a lubricsnt, but it is expensive and not used in our hobby.

But any petroleum-based lubricant will act as a barrier against metal oxidation, which is what the goal is.  I recommend any hobby lubricant you have. I use Woodland Scenics lubricants, but LaBelle or Atlas Conducta-lube will work too.  Or any other lubricant sold for lubricating model trains.  And no, Counducta-lube is not electrically conductive.

[narrowminded]

Pretty sure nothing, because these particular models don't have any bronze contacts.   

Polishing the truck-to-chassis contact points did help.   For "conductive lubricant", what do folks recommend? Something I can get at the hardware store hopefully?

CRC 2-26.  Plastic safe, available at Home Depot and elsewhere, I'm sure.  Does help with electrical connections but no, it doesn't actually conduct on its own.  It helps with the oxide coating that inhibits the conductivity and a light lube as well that affords some atmospheric protection.  Much akin to Atlas Conducta-Lube (if not the same). 

It comes in an aerosol can but don't use that to apply to your model.  Spray some in a jar and apply with a toothpick, microbrush, or the small tool of your choice.

[mecgp7]

What does that do to improve electrical contact?  On my models I usually bent them out further to put more pressure on the contacts.  I thought that would make a more reliable contact of the wheels and metal frames

Even Atlas says they didn't do much and to remove them. You'll find the trucks more "flexible" in that it allows the axles leeway to follow the track. Check it out with a turnout.
How does it improves contact? I guess free wheels and all I know is that you can improve the performance of these chassis if that is the only thing you do.

[nickelplate759]

Here's the new Gyra-Lite lit up.
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I'm almost done - I just need to do something about the number boards and paint the frame and hand rails - waiting for Adhesion Promoter to arrive.  You can see that the end rails (done without adhesion promoter) need redoing.

[peteski]

Nice!

As for painting the Delrin plastic handrails, to minimize paint thickness I do not use adhesion promoter. Instead I sandblasted them with aluminum oxide media shot through a Badger air eraser.  Then I airbrushed a thin coat of Pactra  paint for polycarbonate RC car bodies, followed by the final color of Accu-Paint (Nowadays I would use Tru-Color paint).