STAND ALONE TTS DECODERS

[mjb1961]

Hi ,,,,,I'm sure many of you have bought these stand alone tts decoders and fitted them into your nice locos ,so the question is ,,,do they still have the juddering when running at slow speeds ,,,I know about the agorythm and 128 speed steps because I have 5 tts steam locos  but was wondering if hornby have managed to put the problem right ,after all there were a lot of complaints and returns ,,,,could anyone advise  this question ,,,,look forward to hearing from you guys ,,,,THANKYOU in advance ,,,mjb

[Howbi]

I have bought two TTS fitted locos and 5 TTS decoders.........five of them I changed the algorithym and two were ok out of the box........no other problems found.........like any other mass produced budget product there are bound to be a number of substandard pieces but, for the price, a good buy........HB

[jane1707819582]

different loco's will have different motors so any default settings may or may not work with different types ,  i have had to alter the P I D control on most of my loco's at some point ,as a motor begins to decelerate it will still generate a back emf ,this feeds into the decoder ,the decoder will then try to match the speed of the motor using PID ,each motor will have different characteristics and each modeller will have his/her own view as to acceleration/deceleration and back emf control .loksound require adjustments just the same ,there are 6 cv available on a tts decoder and adjusting these usually cure the problem ,and that is assuming the motor has no problem to start with .

i have found that different dcc systems can also contribute to the need to adjust the cv settings ,other contributors may be able to confirm this 

[96RAF]

I think the OP is confusing jerky running of some locos with the other problem of uni-directional programming and operation highlighted as jane2 said when using other make controllers, which was a true fault and promptly fixed by Hornby.

 

There was also the case of some juddering was a motor problem not decoder related.

 

The TTS leaflet provided with each decoder regardless of stand alone or pre-installed tells of the motor algorithms and the possible need to adjust the motor PID characteristics using the associated CVs and it also mentions BEMF, so its not a new thing nor is it a fault with the TTS decoder, more a characteristic of certain motors and even the drive train of the loco they are installed to.

 

To summarise jerky slow running is usually curable by adjusting various CVs. Some decoders are better at slow speed control than others, but if you want sound as well then you are more limited in choice and possibly by your wallet.

 

Rob