Poor power pickup on Atlas RSD-4

[danjo]

I picked up a couple of Atlas RSD-4s (ATSF #2101 and #2105) from the run of RS-3s and RSD-4/5s that just hit stores last week.  Both suffer from spotty power pickup.  I've tried everything I know to get these running better, but they still run poorly. 

Here are the things I tried:
1. Adjusting contact strips. Didn't help.
2. Swapping trucks front to back, and from unit to unit. Didn't help.
3. Reversing trucks. Didn't help.
4. Hardwiring trucks to decoder power pickup. Didn't help, now undone.
5. Removing wheel wipers from trucks and cleaning the power pickup cups. Didn't help.
6. Loosening frame screws and attempting to adjust frame and re-tightening. Didn't help.
7. Removed 3 axle trucks (2 axles powered, 1 not), and put in 2 axle trucks from an Atlas GP7.  This did seem to help, but obviously isn't a viable permanent solution.

After all of this not helping I read something that suggested checking for the engine being able to wobble from side to side.  I placed the locomotives on some glass, and saw that both locomotives fail to have all the wheels touch the glass at the same time.  The wheels on only 3 out of 4 truck sides are ever touching the glass.  The wobble is not side to side on a single truck, but diagonal across the engine, like front-right to rear-left.  This seems to make it easy for any little bump to cause the locomotives to lose power.  When riding on the 2 axle trucks from the GP7 the wobble doesn't seem as bad.

The diagonal wobble seems to suggest that the locomotive frames might be warped or torqued. Are warped frames a common thing from Atlas?  Has anyone else run into this and have a solution?

Thanks,
Dan

[AKNscale]

I've seen frame warping on the longer Atlas locos like the SD50s. I'm having the same issue with one of my IM SD40-2s. I would check to see if the frame halves are even where the trucks ride, and as you mentioned, make sure the frame isn't warped.

[peteski]

Here are the things I tried:
1. Adjusting contact strips. Didn't help.
2. Swapping trucks front to back, and from unit to unit. Didn't help.
3. Reversing trucks. Didn't help.
4. Hardwiring trucks to decoder power pickup. Didn't help, now undone.
5. Removing wheel wipers from trucks and cleaning the power pickup cups. Didn't help.
6. Loosening frame screws and attempting to adjust frame and re-tightening. Didn't help.
7. Removed 3 axle trucks (2 axles powered, 1 not), and put in 2 axle trucks from an Atlas GP7.  This did seem to help, but obviously isn't a viable permanent solution.

You mentioned lots of things but the most basic: clean the wheels themselves.  Unless you did that but didn't think it was worth mentioning?

If other trucks worked well, and if you hardwired the original truck's side bearing pickup plates then this points to the problem upstream from that area: that means the wheels themselves, and/or the pointy axles and bearing cups. Did you clean them both really well?  Or maybe the wheelsets are too loose in the truck (too much side play)?

[u18b]

Aside from the wheels themselves, like Petski said...

There may be one other possibility.

Spotty pickup means poor electrical conductivity somewhere.

So I would clean all contacts where one piece of metal touches another.
You've already cleaned a couple.  That's good.

How about the pickups in the tucks themselves.   You mentioned cleaning out the cones- that's good.
But the cones get the electricity from the wheel points to the pickups.

How about the other end?   The little bump are sort of tab that goes up from the truck and actually interfaces with those long pickup strips on the side of the loco frame.    I find these need cleaning.  I take some fine grit sandpaper (remember they are rounded) and clean them until they are bright.

Here is a pickup shoe from an Atlas SD50.   That curved top edge is what sends the electricity up to the chassis.   That little edge needs to be cleaned.

http://www.trainboard.com/highball/index.php?media/6-axle-hop-clinic.64293/full&d=1435996990


To me, this explains why the same chassis ran better when you placed another set of trucks on it.  Aside from the wheels just mentioned, the pickups are the only other variable.

[MK]

I was about to mention the factory "coating" of the wheels.  They have to be "worn" off.  But Peteski has already mentioned the wheels. 

[u18b]

I could be wrong... but while warped frames might effect performance and looks a bit,  as long as things are touching that should be touching electrically, I don't think it would have an effect on intermittent operation.

That's why based on what you have written, I think the best bet is it's either the wheels or the truck pickups.

[cbroughton67]

You mentioned lots of things but the most basic: clean the wheels themselves.  Unless you did that but didn't think it was worth mentioning?

I didn't see cleaning the track mentioned. I hate to sound like "Mr. Obvious," but track cannot be overlooked, either.


Have you tried connecting test leads directly to the chassis, thus bypassing the trucks and pickups? That will bypass the trucks altogether, in case the issue happened to be one of the tabs on the motor brushes not making solid contact with the frame, and not the trucks at all.


Chris

[JanesCustomTrain]

I picked up a couple of Atlas RSD-4s (ATSF #2101 and #2105) from the run of RS-3s and RSD-4/5s that just hit stores last week.

As these models seem to be brand new, send them back to Atlas for WARRANTY exchange and let them deal with it.

Jane

[brokemoto]

It is a good thing that you bought both.  Once you address the contact problems, you will find that they are anemic pullers.  They seem to do allright in pairs, but not single units.  The problem is the geared wheels. The prototype, of course, was C-C.  The model is geared B-1-1-B.    The idler axle detracts from the pulling power.

Conversely, the Kato RSC-2 is geared C-C, even though the prototype was A-1-A.  The Kato RSC-2 is a good puller.

[Cajonpassfan]

I looked at them, liked the looks, but wistfully decided they were just a bit new for my era. I need to keep my focus.

Reading this, I'm glad I did. It's ridiculous that in this day and age, Atlas would release formula second generation units that have electrical pickup issues, and add insult to injury, if true, by producing locos that don't pull well. I would have thought we've gotten beyond that in N scale, especially with respectable companies like Atlas. Frustrating, it's like going backwards. Makes me think twice about preordering future releases. Too bad...
Otto K.

[mu26aeh]

I'll go with make sure the track is clean and factory coating is off the wheels. 

[mecgp7]

I had a GP38-2 that behaved badly out of the box. Very spotty like the track was dirty, but it wasn't. The cups that take the needle ends of the axles were filled with an oil-like substance. It wasn't grease. I cleaned them out and the ends of the axles, but it only improved performance a little. I needed to really clean both with alcohol and almost burnish each piece. Problem solved, but it took a lot more effort than you would have thought.

[brokemoto]

The cups that take the needle ends of the axles were filled with an oil-like substance. It wasn't grease. I cleaned them out and the ends of the axles, but it only improved performance a little. I needed to really clean both with alcohol and almost burnish each piece. Problem solved

^^^^^^^^^^^^^^^^^^^^^^^THIS, THIS and THIS^^^^^^^^^^^^^^^^^^^^^^^^

I do not know how many N scale diesels that I have had from various manufacturers that have shown jerky running qualities or frequent stalling and this has turned out to be the problem.  As everyone knows, the Number One Enemy of all things N scale is DIRT.  Once I clean the track and check the contact strips, the next thing for which I check is dirt.  Sometimes, I find dirt devils caught in the trucks.  I noticed the crud's caking up in the ends of the needlepoint wipers the first time when I took apart  a truck to clean the components.  I noticed that when I swabbed with LL track cleaner, it got out the crud, but the cups that accept the needlepoint axles were discolored.  I took a dull eXacto blade and scraped until I got shiny bronze. Once I put the thing back together, everything was fine.

The worst offenders always were LL metal frames, but they did not have a monopoly on it.  Atlas, Kato also offended.

I am not sure what it is.  I wonder if it is wheel black.

[nkalanaga]

As most are made in China, I wonder if the excess grease in the trucks is an attempt to limit corrosion during the ocean voyage over here?

As long as the inside of the container stays dry I don't see why sea salt should corrode the truck pickups, but someone might be worried, and a little over-protective.

[Doug G.]

Kind of like packing military guns in cosmoline?



Doug