Atlas HO Trainman 38-2 drive

[faraway]

I have a many Trainman GP38-2 and GP39-2 engines and some of the drives have been used to power Athearn GP38-2 RTR etc. I love those drives because of their outstanding silent and smooth operation.
I got three more Trainman HO GP38-2 over the last weeks and all are a big disappointment. The outstanding quality is gone and the drives run average at best.
The reason is a changed motor and drive shaft. The old world class motor part #920100. The new one is #921100. The old drive shaft is made of 5 parts the new one is one part only. It looks very cheap.
You should have a look at the parts drawing prior purchase and make sure you get an "old" drive if you need the smooth drive. The part numbers and the one part only drive shaft are easy to identify on the drawing.



My "new" unsatisfactory drives are found in UP 579 and UP 586 as well in a new CR 8214 with the Q paint scheme.

I wrote a letter to Atlas complain about the quality reduction. A Trainman engine wit a downgrade drive is endangered by a similar Bachmann engine with the newer upgrade Bachmann drives. Something I did never expect.

[Schraddel]

Yeah, the old downgrading play and the hope the most of the model railroaders would'nt take notice of the lower quality of the drive train.



May be, the most would'nt notice it, but not all of us!

Lutz

[faraway]

Lutz, thanks for the photo of the "cost optimized" motor. That is what happens when accountants rule the business.
I am curious what motor will be used in the Silver and Gold series. Atlas plays a very dangerous game. The high quality drive is one of their greatest assets.

[Schraddel]

Reinhard,
this can motors look all the same from the outside. The outer sizes are of standard dimensions for Far East all motor manufacturers.
Actually they can be good and on the other hand they can be bad. Depending on the specifications which are ordered by the buyer. And the buyer in this case is the model railroad manufacture. Or worst case, the cost optimizer of this particular manufacturer.

A cheapo motor for use in a toy (of course for this toys who have to endure from twelve o' clock till high noon ):
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And a better one suitable for use in model locos:
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Not the best one, but lower middle grade of quality.
It seemed the Atlas model has got one of these.
Intermountain has this motor size too.

I remember the Atlas locos had mounted a Mashima motor before (one of the better smooth runner)
But ... two days before today i have ordered one of the newly announced Atlas ALCO RSD-4/5 locos
Will they come with unsatisfacturing drive trains :?:


Lutz



For those interested, here is a link to one of the leading manufacturers of small electric motors:
<!-- m --><a class="postlink" href="http://www.mabuchi-motor.co.jp/en_US/product/p_0306.html">http://www.mabuchi-motor.co.jp/en_US/pr ... _0306.html</a><!-- m -->
This is the standard range, most motors ordered by model rr manufacturers are equipped with two motor shafts.
And there are some more manufacturers in China.

[faraway]

A side by side comparison.
The old one on top and the new one at the bottom. They are either from different suppliers or at least very different models. I assume the supplier has been changed for costing reasons. The Atlas standard motor was always very distinctive from cheep toy motors.


I am surprised not to hear an uproar. I remember well the flood of nasty comments when the dimensions of the first batch of Genesis GP7/9 were not perfect. Athearn corrected it and ok. Atlas screws a fundamental part like the motor and nothing happens.

ps. The new one has no drive shafts and one motor wire is disconnected. It has been demoted to a dummy

[Schraddel]

Reinhard!
Yes i see your photo. The black motor seemed to me a Mashima brand. Also i have seen them in some of P2K and Athearn-Genesis switchers which are known to be smooth runners. But not all of the new can motors are really bad.
One of the simplest and quickest ways to judge a motor is turning it over manually with your hand.
Turn it over with your finger tips at the flywheel and pay attention to the cogging. No or at least very low cogging forces are better than high cogging forces.
Motors with high cogging forces are bad for model railroad purposes because the strong cogging is responsible for the jerky movements at low speeds.
Even in DCC mode with an decoder which has a very good Back-EMF goverment and with the PID parameters adjusted, those "Super-Coggers" are not running satisfacting at low speeds.
You can simply descibe switchers with cogging motors: "There is no satisfaction in the action!"

Lutz