I hope I ask this right. I have some Bachamnn HO NS Heritage units DCC / Sound. Some are SD70ACe's and some are the ES44's. I noticed the 70's start moving at speed step 12 and the 44's start moving at speed step 2. (Using Digitrax if that makes a difference.) I can MU a 70 with another 70 without a speed problem and a 44 to another 44 without a speed problem. When I put them on my JMRI test track and have the decoder read, it gives me an option of picking a 70 or 44 decoder no matter which loco it is. If I selected a 44 decoder when the actual locomotive is 70 decoder, would that make a difference on how the locomotive performs? Also something I haven't looked at is the speed cv's settings on each one. I think they are somewhwere around cv60. Would that make a difference? Thanks
willy6I noticed the 70's start moving at speed step 12 and the 44's start moving at speed step 2. When I put them on my JMRI test track and have the decoder read, it gives me an option of picking a 70 or 44 decoder no matter which loco it is.
When I put them on my JMRI test track and have the decoder read, it gives me an option of picking a 70 or 44 decoder no matter which loco it is.
surprised someone more familiar with speed matching hasn't commented. i have no experience do this.
but it seems pretty obvious that if two locos physically move at different speeds at different decoder speed steps, you can't run them together and expect them to operate very well. the heavier one is more than likely to either drag the other forward or hold the other back
my understanding is either a speed curve can be adjusted or a speed table created so that both locos run at pretty close to the same speeds for at least the most frequently used speed steps. and i believe this is a tedious task.
greg - Philadelphia & Reading / Reading
willy6it gives me an option of picking a 70 or 44 decoder no matter which loco it is.
This is unclear. Are you saying that JMRI says that it is the same decoder in both engines?
"my understanding is either a speed curve can be adjusted or a speed table created so that both locos run at pretty close to the same speeds for at least the most frequently used speed steps. and i believe this is a tedious task."
No, it is not a tedious task Check the paperwork that comes with the loco and see if it addresses speed steps 2, 5, and 6. These are the minimum, maximum, and mid speed set points.
So see what the value of CV2 is for the faster loco. Then reduce this value a little at a time and see if that slows down the faster loco.
If the faster loco runs faster than the slower loco at full speed, then you can either increase the value of CV5 in the slow loco to make it run faster, or decrease the value of CV5 in the faster loco to make it run slower.
If all that is happy, then you can fool around with the value of CV 6 in both locos to get them to be happy at whatever mid speed that makes you happy.
willy6,
Doing a quick check on these Bachmann locomotives, both come with what is called a "Sound Value SoundTraxx® diesel sound package. I would try reading CV2 (Vstart) on the SD70ACe to determine it's value. IIRC, increasing the value will cause the locomotive to start out at a lower speed step. See if you can match the SD70ACe to the ES44's start. Once you do that then you start speed matching the two together.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
maxman, In answering your question about JMRI, in most cases when you put any locomotive on the test track and the computer, link and track is ready, you have the option for JMRI to read the decoder. It will go scan CV8 and CV7 and then a list of decoder / locomotive manufactuers will pop up. When the list pops up some of the decoder / manufacturers will be highlighted indicating which locomotive it might be or in some cases it is an exact pick. On my Bachmann 70's and 44's the highlighted options were for a Bachmann 70 and a 44 along with about 8 others. I don't remember what the others were. So that is where I choose my locomotive to be programmed. Example, last week I was doing a new Athearn RTR SD38 and put it on the programming track and had JMRI read the decoder. after CV8 and 7 were read, the screen popped up and the only highlighted locomotive was an Athearn SD38 OEM decoder. That was an exact hit and programmed fine. Anyway, thanks to all of you for the good answers.
This is proubly due to one being set up for more speed steps on the one than the other. The sound value line can be set to different speed step modes, 14,28 and 128.
I tried changing CV2 and that did not work. I am going to read all the CV's on the 70 and 44. Which CV's should I be looking at as far as speed concerns? Also, if I changed all the CV's on the 70 to match the 44 CV's, I wonder what would happen with that. There is always "factory reset" when in doubt. Thanks again
The Sound Value decoders that Bachmann uses are all basically the same, it's just loaded with different sounds and such depending on the type of engine it's installed in. GE engines have sounds loaded for GE engines, Alcos for Alcos etc.
When Decoder Pro reads the decoder type, it can only identify the maker and type of decoder ("Soundtraxx Sound Value"), then it gives you a list of all the potential types of engines and asks you choose which type of engine you have. Once you do that, it can read all the CVs so you can make any adjustments you wish.
If you choose another engine, you could probably still adjust most CVs OK, but you might not have access to all...like if you click on one of the SoundValue equipped steam engines, you're going to have a hard time choosing which diesel horn you want since the steam decoders are only loaded with steam whistles.
BTW for speed matching CV2 is starting power at step 1, CV5 is top speed, and CV6 (if offered) is the middles speed. To adjust the start speed, I'd change all the decoder's CV2s to zero. Then you can add an amount to CV2 for the engines that start slower than the fastest starting ones. It's just trial-and-error, add say 5 to CV2 and try it, if not enough, add 5 more etc.
p.s. Your questions might be clearer if you referred to the engines with their proper names, calling an SD-70 a "70" or a GE 44-tonner a "44" is a bit vague.