Model Railroading > Sssssssslow Athearn RTR unit

Recently bought myself a new Illinois Central SD40-2 for my DC HO layout, one of the relatively recent sound-ready models... Beautiful model and runs beautifully, but it is without question the slowest unit I have ever seen... It won't even move until the DC power pack is at 65%, and isn't going very quickly by the time it tops out at 100... There doesn't appear to be any problem with the unit, it's just slow, too slow in fact to run with any of my other locomotives... Is there any fixing this, or will I have to run this beauty as a one-unit wonder all the time? Thanks very much...

Posted from Android

I would try taking it apart and cleaning all the gears and motor of all the old lube and then give it some fresh lube.

Have had a number of slow Athearn motors lately. At first a good inspection, cleaning, lube and run in was working just fine. The last SD40 I bought seemed to be slow but never improved after the break-in. Eventually it blew out a DCC board, after quite a while of dis-assembly, replacement, inspection and all those other things I realized the method of attaching the motor winding to the cummutator was quite different than the others. Rather than folding and pressing a little tab, the tab was hanging straight out and the mag wire was soldered to it. The situation was so gross it was shorting to the metal fitting that contains the brush and spring. Watching the motor turn, every so often the post would short out and make a good sized flash. Sometimes the motor would turn again, sometimes not.

Replaced the motor with an older style, with the pressed tabs and it runs like a champ. Looks just fine as well.

Athearn offers a number of replacement motors but they are quite pricey and of questionable quality, based on what I've been seeing on the new models.

An older batch of motors had the bearing method where the drive shaft goes through the frame heat up and squeeze the motor shaft, causing high current and then it would stop entirely apparently until it cooled off. A heavy lubricant gel every month or so seems to have fixed that issue.

Unfortunately, running a Athearn model like this one on DC with a DCC decoder installed is not an ideal setup.

There is nothing wrong with it per se, its top speed is slow and a bit hard on the motor.

review here :

http://mrr.trains.com/news-reviews/staff-reviews/2018/02/product-review-athearn-ready-to-roll-ho-scale-sd40-2

Well I missed that one, is the OP talking about a combo DCC/DC unit  or a straight DC model?

If it has a combo DCC/DC sound board it makes perfect sense to draw lots of current and move slowly. If there is only the lighting board inside then it should run like any other DC model. The phrase 'Sound ready' had me thinking there was only the lighting board inside.

An Athearn unit with a DCC decoder installed will not move until there is 7 volts on the rail from the DC power pack and you should hear sound before that. If it is a nonsound DCC decoder it will not move any faster than a sound unit.

Take the shell off the unit and see if someone has mistakenly removed the dummy plug and left a decoder installed. Next if you find the dummy plug where it should be remove the motor and try it with no drive connections to see how it runs all by itself.

While you have the shell off you could take a phone photo and post for us.

Well now you have me wondering too.  There is no such Athearn venicular as "sound ready".
If DCC ready, it does not have sound or a DCC decoder, and then theOP has an issue with the lokie.
If DC/DCC with sound, it has a Economi sound decoder and my original post is valid.




TCnR Wrote:
-------------------------------------------------------
> Well I missed that one, is the OP talking about a
> combo DCC/DC unit  or a straight DC model?
>
> If it has a combo DCC/DC sound board it makes
> perfect sense to draw lots of current and move
> slowly. If there is only the lighting board inside
> then it should run like any other DC model. The
> phrase 'Sound ready' had me thinking there was
> only the lighting board inside.

Scroll down to the bottom of this page... It says the same thing the box does: DCC Ready and Sound Ready...

http://www.athearn.com/Products/Default.aspx?ProdID=ATH16605

I would assume DCC Ready means it has no decoder, right? Didn't see one under the hood...



Edited 1 time(s). Last edit at 07/27/18 17:56 by MC6853.

Ok, correct no decoder, just a basic locomotive for DC operation.  I guess when they mention sound : ready they mean it has a 
spot designated for a speaker.  If it had a sound decoder it would make basic engine sounds even on DC which I assume it doesn’t.  If it was missing the plug it would not run at all.  If you are hoping to run it with the older blue box Athearn engines, it won’t  run at the same speed - the motor and gearing is different with the newer Chinese engines.  That is one more advantage to DCC, that you can speed match engines of unlike brands or lineage.  If you have other newer Athearn Engines and this one runs way slower, then it has an issue.  If you bought from a retailer and have a receipt, I would send back to Athearn following their return guidelines on their website.  If not , you are kind of on your own, and I would disassemble it and see if anything looks fishy.




MC6853 Wrote:
-------------------------------------------------------
> Scroll down to the bottom of this page... It says
> the same thing the box does: DCC Ready and Sound
> Ready...
>
> http://www.athearn.com/Products/Default.aspx?ProdI
> D=ATH16605
>
> I would assume DCC Ready means it has no decoder,
> right?
>
> Posted from Android

I'm curious if it has the crap motor in it. I'm looking at another SD40 and I'm always looking for SP SD45's. But not if I have to re-motor everything.
t4p.

I wonder if it was a used or returned unit and someone put a decoder in it that is still there. A photo of the mid section of the chassis would help there. Then running the motor with pure DC and no power train connections could better isolate the problem.

TCnR Wrote:
-------------------------------------------------------
> I'm curious if it has the crap motor in it. I'm
> looking at another SD40 and I'm always looking for
> SP SD45's. But not if I have to re-motor
> everything.
> t4p

I have a pair of Genesis FP7's with factory  sound, that have so much current draw, that at full power on DCC.they can barely move 15 scale MPH.....the drive is loose - the motors are junk.  I will remotor them....

The plan is to take the motors out of a pair of Tower 55 GEVO's. One of them is a rare undecorated one. The other a BNSF. 

Bob