Atlas scale speed motors - really slow to get moving

[Bart1701]

Loco is disassembled. Did not see any signs of solidified cream-colored grease anywhere. Everything looked pretty clean to me. Let's wait to see what happens when I receive the Kato motor and get it installed. I'll report back then.

Bart

[mrodtoo]

Looks like the motor replacement is a done deal. For others who want to let the decoder compensate, I saw this article in MRR. It talks about changing the starting voltage in other CV's. It may be worth a try before opting for the surgery.
https://mrr.trains.com/news-reviews/staff-reviews/2018/06/atlas-master-line-n-scale-emd-gp7

[rrjim1]

Looks like the motor replacement is a done deal. For others who want to let the decoder compensate, I saw this article in MRR. It talks about changing the starting voltage in other CV's. It may be worth a try before opting for the surgery.
https://mrr.trains.com/news-reviews/staff-reviews/2018/06/atlas-master-line-n-scale-emd-gp7

Not everyone has that problem, all my Atlas and Kato locos with Atlas scale speed motors start at soeed step 1 with the factory start voltage setting.   

[peteski]

Not everyone has that problem, all my Atlas and Kato locos with Atlas scale speed motors start at soeed step 1 with the factory start voltage setting.

That is exactly why I have been saying all along that the Atlas motor is not the problem here.    But whatever  . . . . .

[rrjim1]

That is exactly why I have been saying all along that the Atlas motor is not the problem here.    But whatever  . . . . .

OK, let me rephrase that, all my locos with Atlas SS motors that are in service start at speed speed one. I have had a few Atlas SS motors in locos that wouldn't and needed repaired. Lets wait until I receive the motor before jumping to conclusions.   

[peteski]

OK, let me rephrase that, all my locos with Atlas SS motors that are in service start at speed speed one. I have had a few Atlas SS motors in locos that wouldn't and needed repaired. Lets wait until I receive the motor before jumping to conclusions.   

Let me rephrase my statement too:  If you use high enough value in CV2 in any decoder and any motor, you can get the motor to start moving on speed step 1.  Otherwise (when CV2=0) the motors will just buzz slightly but won't turn. Unless of course you are using an efficient coreless motor, which will run on very low voltages.

[rrjim1]

Let me rephrase my statement too:  If you use high enough value in CV2 in any decoder and any motor, you can get the motor to start moving on speed step 1.  Otherwise (when CV2=0) the motors will just buzz slightly but won't turn. Unless of course you are using an efficient coreless motor, which will run on very low voltages.

with the factory start voltage setting.   

[peteski]

with the factory start voltage setting.

Well then rrjim1, you are *ONE LUCKY MODELER*. Good for you!  I think you have magical powers (or maybe you are running your DCC track voltage around 20V). 

I should expand on this.  Using Digitrax, TCS, or Lenz decoders, with CV2=0 (which is the factory setting, AFAIK) I never seen either Atlas or Kato motors , installed in a model, start running at speed step 1.  The track voltage is around 13V

[rrjim1]

Well then rrjim1, you are *ONE LUCKY MODELER*. Good for you!  I think you have magical powers (or maybe you are running your DCC track voltage around 20V). 

I should expand on this.  Using Digitrax, TCS, or Lenz decoders, with CV2=0 (which is the factory setting, AFAIK) I never seen either Atlas or Kato motors , installed in a model, start running at speed step 1.  The track voltage is around 13V

Well then you must consider A Digitrax PS 2012 set for N and a Digitrax DCS 100 magical because it must work 1000 times better than you system.

[peteski]

Well then you must consider A Digitrax PS 2012 set for N and a Digitrax DCS 100 magical because it must work 1000 times better than you system.

Then I concede that the system I own, and few more systems on friend's layouts (including a Digitrax system) all suck!  I guess I'll be tweaking CV2 for the rest of my life.

[greenwizard88]

A few things.

Tweaking CV 2, 5, and 6 (startup voltage, max voltage, and midpoint) can give you a better speed curve. I suggest doing that.

Atlas has a run of ALP45-DP's that take about 5 minutes to get "warmed up", and it's terrible. Supposedly there's an issue with the brushes or bearings or something. Can you replace the brushes? That would be mighty small, but might save some money.

My most recent Atlas purchase is an SD60E, and it doesn't have this issue at all. It only varies by 2 or 3 scale MPH between a cold start and running for a long time. Point is, this isn't all atlas motors, just some.

[Bart1701]

I wanted to post a final update to this topic.

Jim (rrjim1) gladly swapped one of his Kato motors for my Atlas motor. He tested the Atlas motor he received and said it was working just fine. He was happy to get another Atlas Scale Speed motor!

I installed the Kato motor into my Atlas locomotive and I am very satisfied with the way the locomotive operates now.

So, this little swap has resulted in 2 happy N Gauge railroaders – that’s definitely a good result in my book!

To reemphasize the point I was trying to make in this post. I never said the Atlas motor was defective; I was merely trying to say that its operational characteristics were different enough from my Kato and older Atlas locomotives that it was unsettling to me.  To me, it was almost like the difference between driving a car with a 3-speed manual transmission and a car with a 6-speed manual transmission.  Both vehicles will be able to get up to 70 MPH; it’s just that one requires some additional shifting and effort to get there.  I just wanted to get all of my locomotives to have similar operating characteristics.

My thanks to everyone for their thoughts and ideas!

Bart

[peteski]

Thanks for the follow up Bart.

With DCC in play, speed matching could have been easily accomplished by manipulating Cv 2, 5, and 6. But it would have resulted in the Katos running slower to match the Atlas locos.  Seems that you like to run your models rather fast (not that there is anything wrong with that). 

But I 'm still puzzled by the statement you made in your initial post: "Even if I crank up the throttle to around 50 when I start the engine, it still takes forever to get up to speed. I have a smaller layout, with about 30 feet of mainline track, and it may take 2 laps around the layout before it gets up to speed.".

That is not how any motor behaves (slwo or fast speed) (unless there is some other problem with the mechanism, like thickened grease).  If you set the speed to 50, the  model will leap to that speed within a second or two, without any slow momentum like you described.  It would  not take 60 feet of travel. But again, the motors have been replaced, and the important thing is that you are pleased with the result.

[Drgwspup]

Bart, thanks for posting this and the follow up. I have had the same issue with my newer Atlas GP30s that generally get run once a year.

Reading this thread gives me the idea to test the motor out of the chassis.  If it take time to get up to speed, then it is not hardened lube or a mechanical issue.  Then the focus shifts to the motor.

Jim, you mentioned it could be a motor bearing.  Can you say a little more about that?  How would the average modeler deter, and then fix it, if possible.

Also like the idea to adjust the voltage CV.  Has anyone done that to overcome what Bart and I experience?  What were the CV adjusted to?

Thanks!

Mark

[NtheBasement]

I found long ago that a loco that didn't seem to be moving was doing about a tie every 2 minutes.  Best way to look at low speed performance is remove the shell and put a Sharpie mark on one of the flywheels.  You'd be surprised...