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Kato SD40-2 pickup problems Locos and rolling stock
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Regular poster 155 posts Hobbez Regular poster 155 posts
Hobbez

This spring, I purchased a pair of Kato SD40-2 CP snoot locos.  I installed tsunami sound decoders in them both and put them into service on my layout.  After only a few weeks, (really only about 2 hours of run time) one of them simply stopped working while moving along the main.  So, I ended up putting them both out of service and they took a place in the stack of projects that need attention.  This week, they made it to the top of the stack and I have been tinkering on them.  The one that was running when put away was giving me fits, but a reset of the decoder (cv8 set to 8) and reprogramming did the trick and I have it running again. 

This is where my problem comes in.  I am having problems with electrical pickup.  The slightest rocking of the loco interrupts power.  Front truck crosses a frog, stall.  Rear truck crosses a frog, stall.  Wobble in the track, stall.  Reach out and tap it while it's moving, stall.  I un-soldered, cleaned and re-soldered the clips and motor leads to see if that was the problem.  I removed the trucks and cleaned the bronze strip where the truck connects and the bracket that brings power from the wheels to the bronze strip.  I can't test the other loco to see if it has the same problems, as the decoder wont respond.

Anyone have any ideas?  These are my only Kato engines so I have no prior experience with this design.  Does this pickup system have a reputation for poor conductivity.  I am considering removing it and replacing the bronze strips with wires. 

My Bangor & Aroostook blog

http://hobbezium.blogspot.com 
Reply 1
Nelsonb111563 Moderator 2,264 posts
Nelsonb111563

Bronze strips

Hello neighbor! the issue I have come across with the Kato/Atlas/Athearn Genesis (They all use the same form of power pickup) is where the axle end fits into the bronze plate.  This area relies on the axle making contact with the bearing surface.  ANY amount of lint/dirt/crud will interfere with electrical pick up.  My solution has been to solder a short piece of wire to act as a spring/wiper so that when the axle is installed into the plate, the wire will put a slight amount of pressure against the axle providing positive contact. I use .008 Phosphor bronze wire from Tichy.  I'll try to send you some photos of this when I get home so you can see how I did it. 

Nelson Beaudry,  Principle/CEO

Kennebec, Penobscot and Northern RR Co.
Reply 0
Bill Brillinger Moderator 4,904 posts
Bill Brillinger

Kato pickup contact fix

The contacts from the truck to the chassis stink on these Kato SD40-2's.

I made and wired direct wiper pickups for mine:

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Much better!

 

More input can be found here: http://model-railroad-hobbyist.com/node/17516

and here: http://model-railroad-hobbyist.com/node/17538

Bill Brillinger

Modeling the BNML in HO Scale, Admin for the RailPro User Group, and owner of Precision Design Co.
Reply 1
wp8thsub MRH Author 3,348 posts
wp8thsub

Hard wire for the win

I have three of these, and have worked on a couple others for friends.  There's nothing inherently wrong with the mechanisms, but the power pickup just doesn't work.   Hard wire as has been explained above and the Kato SD40-2 is trouble-free.  When you're done, the result should look essentially like a typical Kato with the wires coming up from the trucks, and will work just as well.

Rob Spangler MRH Blog
Reply 1
Nelsonb111563 Moderator 2,264 posts
Nelsonb111563

Nice setup Bill

I like the contact strips!  What thickness of flat stock did you use?  Brass?  Phosphor Bronze?

Nelson Beaudry,  Principle/CEO

Kennebec, Penobscot and Northern RR Co.
Reply 1
Bill Brillinger Moderator 4,904 posts
Bill Brillinger

I used...

I used the original power strips from the Kato unit.

img.png 

Bill Brillinger

Modeling the BNML in HO Scale, Admin for the RailPro User Group, and owner of Precision Design Co.
Reply 1
Hobbez Regular poster 155 posts
Hobbez

Thanks for the great idea and

Thanks for the great idea and pictures Bill.  I will be hitting the bench this evening to give that a try.

My Bangor & Aroostook blog

http://hobbezium.blogspot.com 
Reply 1
Tjbouwhu New member 8 posts
Tjbouwhu

Same Issue With Kato RS2’s

Thanks for sharing this as I have come across the same issue with two Kato RS2’s recently fitted with Tsunami2 decoders...ran fine for a few weeks, and now I can’t seem to get either to run? They cut out at random spots around the layout.

Tom,
Reply 1
robby Active Member 37 posts
robby

Re: Same issue with RS2’s

Yes! Had to hardwire 2 units to get them to even act like they wanted to run. Just ran jumpers from the bus bar on the trucks but had to do some other chassis modifications to get good clearance for the new wire routing. Project complete and these units run like a dream now.

Robby Vaughn

Modeling the L&N CV Subdivision in 1979
Reply 1
dennis461 Regular poster 165 posts
dennis461
Old is new...
I just bought a Kato RS2 with similar problem.
I put a tiny bit of solder on top of the truck tabs.
Works great, may not be a permanent fix.
Reply 1
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