Doh! moment - TCS CN install in Atlas RS3

[nickelplate759]

So, I just completed installing a TCS CN decoder in a new Atlas/China NKP RS3.     Went nicely, until I set it on the track with the body on and remembered that unlike the rest of their hood units the NKP ran their RS3 long-hood first (and Atlas even painted the little black F on the frame in the right place).   

Easily fixed by setting the right CV, but Doh!



By the way, these are pretty darned easy to do.  They have ditched the Kato-style plastic cradle around the motor, which makes routing the motor wires a little easier.   It was chock-full of grease however, so I stripped it down and washed the frames.

[peteski]

So the motor is just loose, floating around in the frame? 

[nickelplate759]

So the motor is just loose, floating around in the frame? 

There's always a smarty pants.   

There's a sort of flanged grommet placed on either end of the motor that fits into small slots in the frame.  It's a little fiddly to assemble (remember, I stripped down the entire engine to clean it), but works fine. If it gets broken it's probably a PITA to replace as I think the flywheel would have to be removed. I've got one more RS3 to do (not tonight though) - I'll try and remember to take a picture.

I actually think the cradle is better - it's much harder to screw up reassembly.

[jdcolombo]

The cradle IS better, but there wasn't room for it in the RS-3 mechanism.  So the flanged grommet was used.  It works.  You won't break it.  But it is something of a pain to get both grommets in place and snap on the other frame half before they move and you have to start all over.

The RS-3 mechanism could use an update.  But mine run beautifully, and sound terrific! 

John C.

[peteski]

There's always a smarty pants.   

Yup - me!   

And the direction bit in CV29 is probably one of the most often incorrectly understood settigns in DCC. I often see people say that if you wire the motor in reverse, all you have to do is flip the direction bit in CV29.  But  that is not how it works.

It reverses the motor *AND* the headlights, so you used it correctly.  It is used to reverse the direction of the entire model (not just the motor). 

[nickelplate759]

Yup - me!   

And the direction bit in CV29 is probably one of the most often incorrectly understood settigns in DCC. I often see people say that if you wire the motor in reverse, all you have to do is flip the direction bit in CV29.  But  that is not how it works.

It reverses the motor *AND* the headlights, so you used it correctly.  It is used to reverse the direction of the entire model (not just the motor). 

Found that out the hard way on my RSD12 where I did wire the motor backwards.  Still fixable with CV changes, but I had to change direction and the settings for the lights (including the Gyralite).

[peteski]

Found that out the hard way on my RSD12 where I did wire the motor backwards.  Still fixable with CV changes, but I had to change direction and the settings for the lights (including the Gyralite).

Well yes, but that is a workaround, not a true fix.  It would have probably been easier to rewire the motor than to make all the CV changes. And if the decoder ever gets reset, you will have to reset all those CVs.  Plus, doesn't the loco still run backwards (when you look at the direction indicator on the throttle)?

[nickelplate759]

Here are a couple pictures of the whatchamacallit (flanged grommet?).  There is one at each end of the motor.

First, in place.  The red oval shows where.



Second, with the motor out of the frame.  The green oval shows the whatchamacallit and the red oval shows where it sits in the frame.

[peteski]

Thanks for refreshing my memory George!
It is a bit of an odd design. Probably just an evolutionary step in the mechanism design.  The the first generation mechanism had the motor pinched directly between chassis halves.  The soft-plastic donut was probably an attempt to quiet the mechanism.

[tehachapifan]

....Plus, doesn't the loco still run backwards (when you look at the direction indicator on the throttle)?

I don't think so...at least not on my system.

[peteski]

I don't think so...at least not on my system.

So you also have a model where you wired just the motor backwards?  Then you used CV29 to reverse the direction and also reprogrammed the front and back headlights to follow the motor, and the indicator on the throttle still shows the loco traveling in the correct direction?

Hmm  . . . I guess I have to sit down to think about it some more.  Yeah, that's right - the direction indicator will show the correct direction.  Silly me. 

[nickelplate759]

So you also have a model where you wired just the motor backwards?  Then you used CV29 to reverse the direction and also reprogrammed the front and back headlights to follow the motor, and the indicator on the throttle still shows the loco traveling in the correct direction?

Hmm  . . . I guess I have to sit down to think about it some more.  Yeah, that's right - the direction indicator will show the correct direction.  Silly me. 

Yep!

[woodone]

that is one of the functions of CV-29 --set direction. but then you have to program the lights so they will be correct.
I just break it down again and re-wire the motor so it is correct.  After several weekS you will forget you had set CV-29 to correct direction- something goes wrong with the loco you reset the decoder and can't figure out why its running backwards.

[peteski]

that is one of the functions of CV-29 --set direction. but then you have to program the lights so they will be correct.
I just break it down again and re-wire the motor so it is correct.  After several weekS you will forget you had set CV-29 to correct direction- something goes wrong with the loco you reset the decoder and can't figure out why its running backwards.

Yes, the  CV29 not really there to fix the reverse-wired motor - it is to run the model in reverse.