Hard wiring SW1200 pickups

[Ed Kapuscinski]

Has anyone hard wired or otherwise improved the pickups on a LL/Walther's/Atlas SW1200 or MTL SW1500?

I'm thinking about trying it for my 1001.

[Mark5]

Some ideas here: https://www.therailwire.net/forum/index.php?topic=39256.0

[peteski]

You shouldn't have to hardwire the truck for reliable pickup, but those terrible pickup strips under the walkways have to be replaced with something more reliable.  I recall someone on TRW providing a template for making  better pickup strips (and which also will not get damaged during shell removal.

If the pickup strips and the truck contacts are kept clean, the pickup will be reliable. I polish them with a metal polish.

[Ed Kapuscinski]

You shouldn't have to hardwire the truck for reliable pickup.

I agree. However...

In my experience, the whole setup is just so damn finicky. I was thinking about using some fine decoder wire soldered to the top of the tabs from the trucks and then screwed to the frame, but I'm not sure of the best placement for those screws.

This, however, has serious promise:

Instead of trying to tap a blind hole, or drill all the way through the frame, you could do like I did on my ancient Minitrix Fs, when I added jumpers between the units.  I jammed pieces of 1/32 inch brass rod into holes just big enough to force them in, then soldered the wires to them.  They never worked loose, and ran for years without losing contact, so it should work on your switcher.

[Steveruger45]

How about soldering wires to the truck tabs and the other ends to pcb wedged between the frame halves?
As long as the pcb was double sided or two single sided each end. Thickness such that it will clamp down by the frame screws/nuts but not too wide to upset the frame alignment.
You have to slack the frame screws to get the trucks out and this way the wires would drop out too.
Do drilling and tapping either.

[randgust]

I had one as my 'main squeeze' yard engine for years, looked great.   Tabs were finicky for certain, just a bad design, had to repair them several times by drilling in a new 'post' out of styrene rod and melting it down to hold the tab on the frame.

What got me about these was that Life Like (or Walthers, or whoever) had a blackened wheel metallurgy that seemed to dirt up faster than anybody.   I could park mine for a couple weeks on a track, go to restart it, and nothing....  nudge it back to life, clean the wheels, good again.

After a few years of that it entered the Criminally Annoying stage and an replaced the entire mechanism with a Kato NW2 drive.   That got rid of that problem for good.   Now, they may have improved the wheel metallurgy on current Walthers runs.    Mixed emotions about that, my testing showed that the original LL wheels got a significantly better grip than Atlas, about the same as Kato, so once it got cleaned up it was very good in terms of performance.   But dragging it out of it's stall in the enginehouse every session for a wheel cleaning finally got to me when nothing else needed that.

I've never been a fan of hot-wiring end-axle pickups.  Those wipers, flawed or not, help push the trucks down through the axle points and maintain physical contact to the rails - at least when they are adjusted right.   I've seen more than a few repairs on my Climax kits where they were 'improved' by removing the wipers and soldering to the tabs, had the exact opposite impact of making the trucks semi-rigid and causing more stalling.

[mmagliaro]

How about soldering wires to the truck tabs and the other ends to pcb wedged between the frame halves?
As long as the pcb was double sided or two single sided each end. Thickness such that it will clamp down by the frame screws/nuts but not too wide to upset the frame alignment.
You have to slack the frame screws to get the trucks out and this way the wires would drop out too.
Do drilling and tapping either.

YES.  This is a great approach.  I even used this idea in a steam loco project I did some time ago.

Neat, solid, and yes, it means you can just loosen the frame screws to remove the trucks and the wiring without any tapping or
unscrewing.  Just experiment with pieces of styrene shim to get a fix on the thickness.  Two-sided PC board is commonly available in 1/16" and 1/32" thicknesses.   If 1/16" is too thick, and 1/32" is too thin, just solder a little bit of thin strip brass to one face of some 1/32" to thicken it up a little.  Then you can file it until you get just the thickness you need so that it fits firmly between the frames without messing up the frame width. 

[peteski]

Now, they may have improved the wheel metallurgy on current Walthers runs.   

No current runs.  Walthers got out of the N scale loco market. They sold it all to Atlas.  I don't believe Atlas has re-ran these locos.  Or was this model sold to someone else?  In either case - no more Walthers N scale locos.

[Ed Kapuscinski]

I'll give the PCB trick a try.

Next question: where do I get some small pieces of 1/32 to play with?

[wm3798]

I did one a long time ago putting in a decoder.  Got flumoxed by the tabs losing contact with the frame and/or the trucks.  I soldered a piece of brass wire between the wipers on each side to provide continuous pick up along the length of the engine, like you have with the long wipers on an Atlas or Kato engine.  This served two purposes:
It provided a rigid bridge between the little wiper tabs, which kept them from physically shifting about, and it provided better contact between the wiper and the frame at two points instead a less reliable one. 
Required no extra care or handling during shell removal or truck servicing, as well.

Sorry.  No photographic evidence.

Lee

[mmagliaro]

I'll give the PCB trick a try.

Next question: where do I get some small pieces of 1/32 to play with?

If you search eBay for   double sided PCB .031   you'll find plenty for cheap.  I found a lot of 10 pieces, 3" x 4",  for about 7 bucks, free shipping.
It's really handy stuff to have lying around.  That was such a good deal, I ordered some for myself (they still have plenty).

[Steveruger45]

Yes, this ^^^^^.
But there is another way to do the same thing if you cant wait.
CA some contact strip (wiper) off cut, one to each side of a piece of appropriate thick styrene strip leaving the contact strips a little long and fold them under the frame away from each other and solder the wire ends to those. You could use those short lengths of copper strip Salvaged from a disassembled loco coupler which is used as a centering spring.  You know the ones i mean.
Basically making a styrene sandwich where the styrene is the filling and the copper wipers are the bread.
Does the same thing.

[misiek]

It's my test solution:
Simple strip of "photoetched" plate.
Works with LL/Walthers SW9/SW1200 family.

For MTL SW1500 - I want to create another shape, due of air tanks (I don't check this, yet)

[Ed Kapuscinski]

PCB on the way.

Thanks guys!

Because I'm an attention whore I'll post progress as I make it.