This question has been addressed before, but I don’t recall the comments and can’t seem to find it in the archives…
In example, if we have a loco (with a quality NCE decoder) that does not start to physically move until speedstep 20 what is the best way to cause initial movement to be at a lower number speedstep?
My “assumed answer” to this question is to adjust CV2 (start volts), and a higher number (1-255) will give more juice to the loco at an earlier speedstep.
If the above is correct and the change is made, would I necessarily need to adjust CV5 (max speed) or CV6 (Mid Speed)?
Yes, you are correct. Raising the value of CV2 will give you more starting voltage and therefore the loco should start moving at a lower speed step. However, I would not be messing with CV5 and 6 at that point. I would leave the values of CV5 and 6 at zero so that they would be at the default values for the particular decoder.
Once I was done with CV2, then I would adjust CV5 to give me whatever I wanted the top speed to be, and then adjust CV6 to give me whatever mid-speed I wanted.
You want to adjust CV2 (Vstart) so that your locomotive just begins moving at speed step 001. You don’t even have to fuss with CV5 (Vmax) or CV6 (Vmid) if you don’t want to.
Thank you gentlemen, for the confimation and the good advice.
My BLI, P2K, and Stewart locos all start up as they “should” - IMHO. The two Spectrum 2-8-0s, both with NCE decoders I installed, just sit there until SS 20 or sometimes higher is reached.
While I was 99 percent sure CV 2 was the answer to the problem, I wanted your input to validate that. As you can tell by my recent posts, I’ve been wrestling with a few programming issues and really did not want to open up another can of worms.
BTW, all my previous issues are resolved - thanks to you all and some of the new (to me) links to manuals you all provided.
Exactly correct. And this is definitely one where Ops Mode is the thing. Set the throttle to speed step 1, then start small with CV2 using Ops Mode. If the loco leaps into action, try a smaller value for CV2. If it still doesn’t move, gradually increase CV2 until it can just creep along.
Also, be aware that CV3, acceleration, also comes into play here. I would set CV3 to zero while adjusting CV2. Higher values of CV3 will cause the engine to accelerate more slowly. I have one locomotive, an IHC steamer with a Tsunami decoder, that starts like a jackrabbit even when CV2 is set to zero. By putting a rather large value in CV3, it has a much smoother startup, although once up to speed it still moves along even a speed step 1.
One thing for the OP to realize, much of DCC is not plug and play. Many times you will have trying times. Try this or try that, especially with custom installs. Do a reset. I do that with any new install, then make the appropriate CV adjustments. I use paper and pencil to keep track of CV values.
Do a reset and then see how the loco resounds.
Using a PC with software makes this much easier as the PC keeps the previous values. But that is another discussion.
Adjusted the two Spectrum (HO) 2-8-0s start speed successfully. Had to code in a value of 17 on one and 30 on the other. Neither of these locos have seen much run time, and I suspect they will loosen up a bit once they are fully broken in.
Believe me, I did a LOT of research before I went to DCC 3 years ago, and went into it with my eyes open - knowing full well it was not a “plug and play” situation for me in any way. Having said that, I also realized one could make DCC as easy or as complicated as one wants.
The continuous learning and occasional frustrations are part of the game for me, and as we used to say at Mobil Oil, these are more like “challenges and opportunities”!
When you achieve the results that you’re looking for, Bill, you may want to jot those values down and keep them on file (or store them in Decoder Pro) - i.e. if and when you need to perform a reset. Better than trying to remember…
No one has mentioned the Capacitors in the Spectrum locos; I have been told to cut them off or cut one of the wire legs to remove them from the circuit as it improves slow speed operation.
STep 20 for a non-BEMF decoder isn;t all that crazy. Sometimes AThearn Blue Box locos with the stock motor won;t go until even higher speed steps by default, but that’s what CV2 is all about.
You do not have to change any settings in the decoder to use 128 speed steps, you only have to set the command station to send 128 speed step commands. 14 and 28 speed step commands “look” the same to the decoder, so when using one of them the decoder has to know which one you are using (hence the 28 speed step bit of CV29). The 128 speed step command “looks” completely different from the other two and the the decoder will know that you are using 128 speed step commands without you changing any of it’s settings.