New run of Atlas GP15, check your motor tabs !

[spookshow]

Sounds like much ado about nothing to me.

-Mark

[jagged ben]

I don't regard Atlas locomotives as being 'plug and play' DCC ready anyway.   You gotta disassemble the frame in any case.  Every one of mine gets taken completely apart, the frame gets Kapton taped in the motor area, then the whole thing reassembled and the decoder is installed carefully to make sure the motor contacts make contact.

[tehachapifan]

Sounds like much ado about nothing to me.

-Mark

Sorry to waste anyone's time, but I just wanted to mention it because I purchased an Atlas N Trainmaster with (aftermarket?) DCC on eBay that was advertised as not running. Took a chance on it and found the decoder was fried and there was some melting of the shell I didn't spot in the pics. Found that a motor lead was firmly sandwiched between the decoder and the frame.

[mu26aeh]

And I brought it up bc this is an entry level locomotive, no frills, DC only that some new modeler is going to get and not have any idea why their brand new loco has lights but won't move.  If it was only 1 or 2, I probably wouldn't have said anything, marking it up to a known atlas problem.  But the fact they batted 1000 on all 10, felt it needed some attention.  Perhaps not here, but broader audience

[peteski]

If it was only 1 or 2, I probably wouldn't have said anything, marking it up to a known atlas problem.  But the fact they batted 1000 on all 10, felt it needed some attention.  Perhaps not here, but broader audience

The big question is: has anybody actually notified Atlas?  While Atlas has/had few of their employees as members here, they might not visit often (if at all).  With such a high percentage of poor workmanship, someone should let Atlas know.

[mu26aeh]

The big question is: has anybody actually notified Atlas?  While Atlas has/had few of their employees as members here, they might not visit often (if at all).  With such a high percentage of poor workmanship, someone should let Atlas know.

I posted earlier that I emailed them overnight.

They are ears to the bottom of the frame halves, no wires or pickup strips

I emailed Atlas overnight and have already received 2 emails from them looking into the situation

[peteski]

I posted earlier that I emailed them overnight.

Sounds like they are listening (better than I read). 

[greenwizard88]

I thought these days that decoders had short circuit protection. At least, the Digitrax ones I used to use were advertised as such. So wouldn't it still be much ado about nothing?

https://www.digitrax.com/tsd/KB933/motor-isolation-protection-fx-fx3-decoders/

[peteski]

I thought these days that decoders had short circuit protection. At least, the Digitrax ones I used to use were advertised as such. So wouldn't it still be much ado about nothing?

https://www.digitrax.com/tsd/KB933/motor-isolation-protection-fx-fx3-decoders/

Short circuit across the motor output is *NOT* the same as connecting the motor outputs to the track power.  That is not by definition a "short". Give a try and see what happens!   

[tehachapifan]

An exposed speaker wire or contact touching the frame will also not trigger any short protection, and the consequences are swift, severe and without warning. Ask me how I know!

[greenwizard88]

Short circuit across the motor output is *NOT* the same as connecting the motor outputs to the track power.  That is not by definition a "short". Give a try and see what happens!   

They call it motor isolation protection (my bad for calling it short circuit protection). I haven't tried to see if it works, but I don't believe it's related to the motor shorting out, but rather the motor not being isolated from the track.

On the flip side, Tsunami 1's have this explicitly in the manual

Failure to properly isolate the motor will damage your decoder and turn it into an effective, but short-lived smoke generator!

so I guess it's not as universal as I hoped.

[peteski]

They call it motor isolation protection (my bad for calling it short circuit protection). I haven't tried to see if it works, but I don't believe it's related to the motor shorting out, but rather the motor not being isolated from the track.

I really don't have much of an dea on how such protrction coule be implemented. Back-feeding DCC voltage (or alternating polarity) to the output of the motor driving H-Bridge transistors seems like good way to release the magic smoke.  But then I'm just a lowly electronic technician, not a design engineer.  Hey, maybe they are sensing the voltage present at the H-Bridge output while it is turned off.  If the decoder sees a voltage when it is not commanding the motor to run, it will just keep the H-Bridge turned off. 

But even if the manual for some decoder explicitly stated that the "motor isolation" protection will kick in, I'm not willing to test it.