Cross-wiring 2 locomotives as A/B unit?

[Jetrock]

I'm a fan of older interurban railroads, which means finding obscure 1960s brass locomotives, and they generally don't run well. Suydam made a lot of interurban passenger cars with OK motors and mechanisms, but power pickup was unreliable--each truck delivered power from one rail but not the other. This means that, even though the motors have decent slow-speed performance, especially after replacing the old magnet in the open frame motor with neodymium supermagnets, they tend to stop dead where there are gaps in the rail. But I'm hatching a plan to attach two cars (a coach and a combine), one of which is powered and the other a dummy, with the power leads from both sets of trucks into one motor. Theoretically this would have power pickup from four different points, and potentially more reliable operation over small dead spots in the track, right? Has this been done before, such as with a pair of diesels with an A and B unit, wired in tandem?

[gmpullman]

I did this with my "pair" of PRR DD1 motors. I used a fiber drawbar since each frame was electrically continuous with each rail. I use DCC but it wouldn't matter in any case.

In this photo I am merely test-fitting the decoders:

DD1-DCC by Edmund, on Flickr

Somewhat difficult to see here but there is a jumper wire and plug between the pair which carries the rail pickup between the units. Pickup is only at four points on each unit, two from the pony wheels and two from the drivers.

PRR_DD1-fi3 by Edmund, on Flickr

This works very well to help mitigate any pauses in the power collection. I was fortunate, too, that the pair of motors in the DD1 were very smooth and strong.

Good Luck, Ed

[Mykhalin]

Have you considered adding a "keep-alive" circuit to your cars? Also, depending on your skills and the track and model configurations, it might be possible to mount a non-conductive beam (wood or styrene) to the underside of the truck and add pickup shoes to it for getting power from both rails. I'm pretty certain that the MR archives is chuck full of wiring ideas from the 1930s, 40s, and 50s (if not later).

[SeeYou190]

I did this with my heavyweight pasenger train. All nine passenger cars and the Athearn PA/PB locomotives are wired together. I did this to control light flickering in the passenger cars, and it worked.

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-Kevin

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[doctorwayne]

Jetrock

Theoretically this would have power pickup from four different points, and potentially more reliable operation over small dead spots in the track, right? Has this been done before, such as with a pair of diesels with an A and B unit, wired in tandem?

My locomotives are all steamers, but for brass locos or older metal ones, like this Bowser A5 which I built for a friend...

...I add all-wheel pick-up, using phosphor-bronze wire as wipers for all wheels...

Despite its short wheelbase, nothing seems to stall it.

This Bachmann USRA 2-6-6-2 came with all-wheel pick-up on the loco, but I added it to the tender and the auxilliary tender, too...

....and I did the same for these brass steamers...

It's easy to do, and makes for better-performing motive power.

Wayne

[Canalligators]

I’ve added power pickups and they help a lot, once you get the contact tension right.  I second using copper clad board.

I MU‘d diesel locomotives using memory SIP sockets and jumper wires that looked fairly realistic.  See my article “Operating MU Connections” in Sept. 1992 MR.

[Jetrock]

Some great ideas here! Thanks for the advice--and the photos!

 

I don't run DCC, so a "keep alive" won't work--but maybe that's just another reason to make the jump. Some of the ideas about extra power pickups and wiring a whole passenger consist together are very intriguing. I tested out the idea yesterday but my soldering skills are not up to par--and I didn't realize until after the solder broke on both ends that I had also inserted a wheelset backwards, causing a short circuit when I tried to test! Back to the drawing board...

[Eilif]

A keep alive capacitor isn't just for DCC.  AFAIK, it could be just as usefull for DC. I think the use I most often see for it on DC is lights in passenger cars. 

As for wiring two locos together, it's somethign I plan to try at some point.  I havea.  A some old AHM BL2's that I like, but are single truck drive locos and not really worth investing in a whole new powered frame.  Wiring two together and possibly also adding wipers to the unwired trucks on each loco should make them pretty reliable.

Of course just running two instead of one already gives significant improvement over running just one.

[RR_Mel]

I’ve never had problems with power pickup in my locomotives but passenger car lighting has always had some sort of problems

 

I wire my passenger cars together but not at track power.  I rarely uncouple my passenger cars, normally only for maintenance, so connecting the micro connectors isn’t a big thing for me.

 

 

The wires & connectors are hidden in the diaphragms.  I power the lighting from the baggage car.  The little brass screw in the doorway is a trim pot for adjusting the individual car lighting brightness.

 

 

 

 

I use 4 volts for my LED lighting.  I built a track powered charger to top off the onboard Lithium battery.

 

 

I use a latching magnetic reed switch in the center of the baggage car to turn on and off the entire passenger lighting using a magnetic wand when I’m operating in DC mode.  I paralleled the reed switch with a Digitrax TL-1 for DCC control of the lighting when I’m operating in DCC mode.

 

The ability to leave the passenger car lighting on with no track power is a great advantage for me.  I normally leave my passenger trains at my passenger station for long periods of time without track power and having the lights on is a big plus for me.  The battery will keep the lights running for hours then be charged when track power is restored.

 

In DCC mode it's slick to turn on and off the lighing with the press of F5 on my controller.  This particular passenger train is the Southern Pacific Lark pulled by a Cab Forward up my mountains.

 

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[doctorwayne]

RR_Mel

...This particular passenger train is the Southern Pacific Lark pulled by a Cab Forward up my mountains.

Speaking of mountains...

Wayne

[hgodling]

doctorwayne

...I add all-wheel pick-up, using phosphor-bronze wire as wipers for all wheels... 

What gauge of wire do you use for those wipers?

[doctorwayne]

I believe that the example shown is .020" but .015" and .012" wire should work, too.  I've just started on doing another older Tyco/Mantua Pacific for a friend, and will try the lighter wire.

I'll let you know, in another post here, if it works as well.

As an aside, I've seen where some modellers do it differently:  the one who did the Tyco/Mantua loco originally did a very shoddy job - very poorly done, especially as he charged my friend an outrageous fee, and claimed to have done dozens as a "professional model builder".

He added wipers to only the insulated wheels, and to only two of the loco's three.  While the non-insulated wheels do, of course, pick up current, the pressure of the wipers tends to push the wheelsets outward to one side.  Adding wipers to both sides balances that, which restores proper tracking qualities.

Wayne

[doctorwayne]

hgodling

 doctorwayne

...I add all-wheel pick-up, using phosphor-bronze wire as wipers for all wheels...

What gauge of wire do you use for those wipers?

 

As promised, I used .015" phosphor-bronze wire to add wipers to the Tyco/Mantua chassis, and while they do the job for which they're intended (better electrical pick-up), I found the lighter-gauge wire to be very susceptible to random bending during handling, as I also need to fabricate a bracket in order to add a motor.  Some of the wipers got bent while I was taking measurements, although they were easy to re-align.  Perhaps they'd be fine once on the layout, but I think I'll replace them with some .020" wire, as it seems to be more rugged.

Wayne

[gmpullman]

A seldom seen product, ESU (makers of Loksound decoders) offers a wheel-wiper kit generally designed for rolling stock but easily adaptable to locomotives.

http://www.esu.eu/en/products/interior-lighting-sets/wheel-wipers-powerpack/

Good Luck, Ed

[Jetrock]

Just to update the thread, I tried my cross-wiring experiment again, after picking up a suitable connector at a train show. It worked well enough to improve slow speed performance and operating over dead frogs and crossings--so now the next frustration, derailment due to poor trackwork, has become my next target! Thanks for the advice, everyone. One great thing about this hobby is that there's always more to learn and to try.

[BroadwayLion]

RR_Mel

I use a latching magnetic reed switch in the center of the baggage car to turn on and off the entire passenger lighting using a magnetic wand when I’m operating in DC mode. I paralleled the reed switch with a Digitrax TL-1 for DCC control of the lighting when I’m operating in DCC mode. The ability to leave the passenger car lighting on with no track power is a great advantage for me. I normally leave my passenger trains at my passenger station for long periods of time without track power and having the lights on is a big plus for me. The battery will keep the lights running for hours then be charged when track power is restored. In DCC mode it's slick to turn on and off the lighing with the press of F5 on my controller. This particular passenger train is the Southern Pacific Lark pulled by a Cab Forward up my mountains.

 

 

COOLEST!  THAT is what I want for my subway trains. If you can give me the plans, then I'll get back to work and rebuild my fleet.

 

ROAR

[RR_Mel]

BroadwayLion

 

 

RR_Mel

I use a latching magnetic reed switch in the center of the baggage car to turn on and off the entire passenger lighting using a magnetic wand when I’m operating in DC mode. I paralleled the reed switch with a Digitrax TL-1 for DCC control of the lighting when I’m operating in DCC mode. The ability to leave the passenger car lighting on with no track power is a great advantage for me. I normally leave my passenger trains at my passenger station for long periods of time without track power and having the lights on is a big plus for me. The battery will keep the lights running for hours then be charged when track power is restored. In DCC mode it's slick to turn on and off the lighing with the press of F5 on my controller. This particular passenger train is the Southern Pacific Lark pulled by a Cab Forward up my mountains.

 

 

 

 

COOLEST!  THAT is what I want for my subway trains. If you can give me the plans, then I'll get back to work and rebuild my fleet.

 

ROAR

 

Check your Forum Mail

 

 

Mel

 

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.