0 Members and 1 Guest are viewing this topic.
Now that I have switched over to NCE for my new HOn3 layout (just for a change and my Digitrax went with my layout when sold) I needed to purchase a serial port to USB cable from ESU (best one to purchase) so I can connect my old laptop to the NCE command station according to JMRI experts to be able to adjust the sounds and other features in my Blackstone K27's. The NCE command station I have only has a serial port with which to connect to a PC. Folks much smarter than me strongly suggested not to purchase any other brand.Rod.
Tonight, I hope to watch a video that I found on YouTube about speed-matching with an Accutrack II speedometer and LokProgrammer. Since I have both of these pieces of hardware, I want to check out if this is the new way I will speed-match.DFF
FWIW, I've used an Accutrack, and although its fun to see the digital readout of the speed as the engine runs through it, I've found that the "old fashioned" method actually works better (plus you can't really use the Accutrack to adjust momentum). That method is this:1. Find out which engine you are matching is the slowest in unmodified running.2. Set the 3-point speed curve (CV's 2, 5 and 6) to get what you want for start, mid and max speed. Turn momentum off (e.g., CV3 and CV4 = 0).3. Put the same CV values as you got in Step 2 into the engine you want to speed match (the faster one). It's momentum should be off, too.4. Put both engines on the track, separated by about 4 inches. Consist them. Crack open throttle and observe. The faster engine probably will close slightly on the slower one, although maybe not at speed step 1, which will be mostly controlled by BEMF anyway. Adjust CV2 using ops mode programming in that engine to match the slower engine if need be.5. Separate engines by 4" again. Advance the throttle to 50%. Observe. The faster engine will close on the slower one. Adjust CV6 on the faster engine until it matches speed.6. Advance throttle to 100%. Repeat the observe/adjust for CV5.7. Adjust momentum for slow engine to what you want (ESU uses a default of 80 for files equipped with Drive Hold, and I find this to be pretty good).8. Put same values in Engine 2.9. Check acceleration momentum matching by putting engines on track, separated by 4", consist, and turn throttle up quickly to 100%. If they don't match, adjust Engine 2's CV3. Then crank the engines up to 100% throttle, quickly turn throttle to zero, and observe whether braking momentum matches. If not, adjust CV4.You're done. This sounds harder that it is, although I've never tried it with an NCE system (I use Digitrax). But I do get perfectly matched engines this way.
BTW, if you have grades on your layout, you might find that adjusting the BEMF cutoff (CV56) is useful to keep consisted engines from "bucking" going downgrade (maybe upgrade, too, although that's usually not a problem). If bucking is a problem going downgrade (or any time), set CV56 in each engine to 120. If bucking persists, lower the value in CV56 until it disappears (but don't go below about 50 - you need BEMF on at low speed for best low-throttle response).
BTW, if you have grades on your layout, you might find that adjusting the BEMF cutoff (CV56) is useful to keep consisted engines from "bucking" going downgrade (maybe upgrade, too, although that's usually not a problem). If bucking is a problem going downgrade (or any time), set CV56 in each engine to 120. If bucking persists, lower the value in CV56 until it disappears (but don't go below about 50 - you need BEMF on at low speed for best low-throttle response).John C.
With ESU decoders, I have found that I can near perfectly speed match (momentum aside) simply by setting the max speeds with the Accutrax II, and then setting a linear speed table (after doing the BEMF auto set). I have yet to find locos which don't consist nicely having done this. If throwing a non-ESU decoder into the mix, wel....But, yes, I still step each loco through a number of other speed steps to validate. And, if I plan to run in permanent consists, I always plan to tweak using the above method; just haven't had to change any CVs in the speed table in over a year while "tweaking".
There was just a thread (Subject:CV 56 and Consisting!!!) on the LokSound Yahoo group about this. One poster recommended starting at 20 if you had this bucking problem. I have not verified since I my flat door has no grades but if you find going down to 50 hasn't solved it then lower apparently isn't necessarily bad.
Do you guys find a difference in speeds between a cold and warmed-up loco? That is, at a certain speed step the loco will run at different speed depending whether it is cold (at the start of an operating sessison, after sitting for few days) and when it is warmed up (after running for several minutes).