TTS class 31 running issues

[Dan Griffin]

I need some help from the DCC guys.

I have a. 31 that is TTS sound, and it ran perfectly when installed a couple of months ago. Now all of a sudden its stop start all the time. I have stripped the bogies and drive train and removed any hardened grease. So everything is free to roll, its not a power issue as everything else runs fine and the sound doesnt cut out. Any help would be great.

 

i video of it running is here

https://www.facebook.com/groups/370653914745736/permalink/420527233091737/

[Geep7]

55 minutes ago, Dan Griffin said:

I need some help from the DCC guys.

I have a. 31 that is TTS sound, and it ran perfectly when installed a couple of months ago. Now all of a sudden its stop start all the time. I have stripped the bogies and drive train and removed any hardened grease. So everything is free to roll, its not a power issue as everything else runs fine and the sound doesnt cut out. Any help would be great.

 

i video of it running is here

https://www.facebook.com/groups/370653914745736/permalink/420527233091737/

I'd check the gears in the bogies. This suspiciously looks like a gear is either split or has lost a tooth, sometimes something that isn't immediately easy to spot.

[Dan Griffin]

14 minutes ago, Geep7 said:

I'd check the gears in the bogies. This suspiciously looks like a gear is either split or has lost a tooth, sometimes something that isn't immediately easy to spot.

I have checked the gears. As i stripped the bogies right down.  

[WIMorrison]

I would switch off the sound and then try to run it - you are masking all the mechanical sounds by having the speaker on.  I think that it will be more obvious that you have a mechanical fault as you will be able to hear if the motor stops - perhaps a bit of dirt on the worm or pinion that is causing the stall.

[Izzy]

Am I correct in thinking that this issue only exists in one direction, or is it just the way the video appears? If it is just one way a mechanical problem is the most likely. Turning off the sound & lights would certainly eliminate power draw overload as the problem, which can affect these decoders. 
 

I know you said the gears etc have been stripped/cleaned/checked, but are the bogie side frames staying properly in place? I just wonder if they have come loose somehow allowing the wheel sets to lose gear mesh/catch in either/both directions. The other thought is the pick-up wires from bogie to chassis have fractured internally giving intermittent current collection, but if the sound continues not really likely.

 

Bob 

[beejack]

I've just got my class 31 out of the box after a couple of years in storage and it is having the same issues. 

Running light engine or pushing a rake of coaches and all seems ok. get it to pull a rake of coaches and it starts speeding up and slowing down before eventually beginning to stop and start as it goes up the incline and no its not slipping, as without sound you can hear the motor physically stops and starts.

Again with mine the sound remains ok if switched on

Tried on the esu decoder tester and the speed of the motor speed wanders up and down slightly.

Put a slight but constant pressure on the fly wheel and the motor significantly slows and speeds up. Increase the pressure and the motor stops and starts.  remove all pressure the motor runs away then slows back down.

So this rules out any pickup issues.

It seems a component on the decoder for the motor output is failing under load or the overload protection is kicking in and out if there is one.

 

This is without lights 

Weird as it was ok before it was put away.

 

As a test I Put a Lenz standard + decoder in the class 31 and it runs smoothly so again rules out any pickup issues.

 

As I bought the decoder quite a few years ago not sure if there is any warranty with Hornby.

I also changed the speaker by cutting the wires and soldering the wires from the new speaker to the existing ones rather than to the decoder.

 

 

 

 

 

 

Edited February 17, 2022 by beejack

[Dan Griffin]

I lost all patience with the decoder itself as I adjusted all CV's as per Hornby's own tech guys said etc and still it wouldn't run properly but sound was fine. 

 

my solution was this. 

 

I inserted a Bachmann 36-566 decoder and tested the loco. everything was fine. perfect running. 

 

after testing I unsoldered the red and black wires from the TTS plug and then wrapped the plug in insulation tape to prevent the pins staying and causing a short.  

 

then I carefully soldered the red and black wires from the TTS Plug to the corresponding red/black wire on the 36-566 plug. 

 

Unconventional, yes! does it now work, yes! however you now have to properly drive the 31, to make the sounds match the speeds. as the Bachmann chip controls the motor not the TTS chip. 

 

so the 31 in essence has two decoders fitted. the Bachmann 36-566 controls the motor and lights with the TTS one providing the sounds. This is still cheaper than buying a high end sound chip although it is galling as Hornby should make the TTS chips better to suit their own locos!!

 

i am happy now though and both sound 31's run and sound good.