I have started setting a lot of my engines to a default like setting. Most, almost all, of my collection has digitrax decoders, and I am trying to use the default settings in the book for CV2, CV5, and CV6 for the respective locomotive type. I realize this won't be exact, but the engines should be close.... Except the Athearns. The RTR engines need a higher numbers to get them going and a good cruising speed, while the old Gensis needed CV2=1 and still starts to fast. I have about fifty engines, and I like to consist many different combinations. I realize that if I want engines to consist well together I have to speed match them. What recommendations are there for default settings among different manufactures?
Nile,
Every locomotive is different - even the same manufacturer and model - so you can't rely on decoder defaults for consistent speed matching. Other factors that can affect it are lubrication and binding (steamers). If you haven't cleaned and relubed your locomotives in a while, this may be a good time to do it.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
You are on target with adjusting CVs 2, 5, 6 to get locos speed easily matched, creating a simple three point speed curve (either linear or dual sloped). That's of course easier than setting all 16 or so speed table items. But it's not about default settings, it's a trial and error process. Some folks take a single loco and match their others to that one so any could be consisted with another. That really depends on whether you want them all to have the same top speed and be able to consist any with another. For example, I want my yard switcher to run slower at top speed than my passenger E units, and won't be consisting them. Some folks set the speed curve by using a speedometer / timing approach.
I just run two locos near each other to get them matched. I typically consist the same type locos with their siblings (e.g., SDs, F units, etc) but have not (yet) made them all consistent with a common one or even several. I simply adjust CV2 for a nice speed step one smoothness, then set to speed step 128 and adjust CV5s (first adjusting one to get the top speed I want, then adjusting the other to match it) to get them running a constant distance apart, then set them to speed step 63 and adjust CV6 mid speed to get similar speeds. I usually set the speed step 63 speeds (via CV6) at less than half of top speed for finer control at lower speeds. I may then go back and adjust CV2 for the loco that's slower at speed step one to run close to the faster one at that speed step. Note the locos do not need to match perfectly to run ok together.
When speed matching, I believe most guides suggest to turn off momemtum. When consisted, many different type decoders work together fine regarding BEMF and some may do better with it turned off so the locos don't fight. When consisted I also recall that some decoders (e.g., LokSound) may have different momentum "factors" so adjusting the consist momentum with my NCE throttle (0-9 steps) may cause inconsistent behaviors. My locos are almost all LokSounds so I can use the throttle and not have to mess with momentum CVs. If I've misstated any of this, others can correct or add to this.
If you had any prior Tsunami's (lacking speed steps 5 & 6) it's a bit tougher. I recall matching a Tsunami GP9 to a LokSound Select RS2. I had to match the top speeds by slowing the faster one with CV5 if the LokSound was faster, alternately using the forward and reverse trim CVs on the Tsunami if it was faster. (I didn't want to get into adjusting the 16 or so speed table CVs which could also be done.)
I love to run consists, as I can have multiple loco sounds and pull more cars easily.
Here's a reference article:
https://tonystrains.com/locomotive-speed-matching-made-easy/
Paul
Modeling HO with a transition era UP bent
On some consist, turning off BEMF has helped with surging and pulling. But not all engines/consist responded well to the change. I also use the momentum setting in my NCE Power Pro throttle. But, my consist are permanant and each engine has the same address.
I don't have any of these problems with engines and consist that are running with the RailPro system.
What it comes down to is that you have to match start speed with the one that starts fastest with the minimum setting in CV2. That's as slow is it will ever start. At the top speed, you have to slow down the faster ones to matchg the slowest one.
You'll never get exact matches with locos with vastly different motors and gearing. No system can fix this. Railpro and others do the same exact thing to match speeds.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Website: http://bobfrey.auclair.com
The initial results in the first chart look more than close enough to MY those locos without problems. I've never felt the need to go all the way to implementing 28 step speed tables to get locos to MU. We never had such capability with DC power and yet people ran 2-3 or more locos together with no issues. DCC is not different.
Some decoders do a better BEMF implementation than others - Digitrax's, at least prior to the latest Series 6 decoders, which I have yet to try, was one of the worst and would cause bucking in consists (which may explain why the default decoder settings were such that BEMF was turned off when using CV19 consisting). TCS and ESU have superior implementations - I just put the locos on the track and couple them up, no speed matching, and never do I have one trying to push or pull the rest, they all start and run very well together, especially when pulling a train, since the weight of the train really evens out the pulling power - like the real thing, each will pull as best it can.
You just need them to be close. If one loco jumps to 15 smph on step 1 and the other can poke along tie to tie on step 1, they will not MU together well. But if one runs at 2 smph and the other at 3 smph, they will work fine as is with no firther adjustment.
I honestly do not understand this obsession with getting every loco in perfect lockstep across the entire speed range. It just makes the DC guys point and laugh at how complicated DCC is while they just grab 2 locos from their engine terminal and couple up to a train. Plus not all decoders do 28 stpeed step interpolation when fed in 128SS mode, which is all I use. There was a huge discussion in the early days of DCC that 14 steps should be plenty, since most prototype diesels only have 8 notches. All those arguing that 14 speed steps (later 28 and FINALLY 128 after being pushed by several US manufacturers) were forgetting one thing - physics does not scale. When you have all that weight of a prototypical train, keeping it in control with just 8 speed options plus the brakes is completely practical, happens every day all the time. But with no coasting to speak of, and very little train momentum, our models to not behave the same way. There's a reason all sorts of complex momentum circuits were developed for model train controls, trying to find a way to accurately represent that huge weight electronically. The TAT V throttle probably had the ultimate, at the time - once you dialed in a particular loco you could make a fixed plug-in module that set critical circuit values to optimize performance of that loco. Switch locos, swap plug in modules and the handling characteristics changed to match the new loco.