Been trying to speed match two Kato SD80Mac. Both with Digitrax DN163K2 Decoders. They run at different speeds and been trying to use JMRI to match them using speed curves. I can't seem to get them right. They close the gap every time and the push and pull derails them. How do you determine a 28 or 128 speed steps (scale MPH) with a Digitrax throttle when the display goes to 100? Should both of the locomotives be warmed up befor starting this process of speed matching, or can you go right out of the box? This is just giving me a headache! Please advise. Peace be with you, Arthur
Hi Arthur I use the JMRI throttle. If you RH click the mouse button in the throttle block that has the speed slider in it, a box saying "Properties" comes up. Click on it and you can change the slider to a 28 speed step throttle. These steps then match the Speed table steps and it becomes a whole lot easier. I generally match speed sets 1,7,14,21 and 28 and then interpolate straight lines between those points. This is generally good enough. Then I match the acceleration and deceleration. Hope this helps, Ted
Remember, on the Digitrax throttle, the 100 means "100%" There are a lot of speed matching techniques documented here on TB and elsewhere. I 100% agree with using JMRI (it is the only way to go). First, determine which of the locos is the "slowest" (i.e., runs the slowest at full throttle). That is the one you want to match to. Then adjust the top speed to where you want it. (I personally tend to set my road-locos so that the top speed is approx 100 smph, so that my throttle reading is sort-of a speedometer), then, as Ted mentions, adjust your mid-points as necessary. Then, and only then, get your second loco on the track, and adjust its speed to match your first at each of the points you used above.
I use a DT402 throttle and ops mode programming (programming on the main) to do this. Process is similar. 1. Determine which loco is the slowest at full throttle. 2. Set top speed for that loco using CV5. Set mid-throttle speed using CV6, and set speed step 1 using CV 2 to whatever values you want to make the loco run the way you want. You can do all of this using ops mode programming as the engine is running. 3. Now program the second loco. Use the same value in CV2 as in the first, and use values in CV5 and 6 that are about 90% of what you have for the first loco (remember that this loco is the faster of the two, so start with values in CV5 and CV6 that are about 10% less than the value for Loco 1). 4. Set the second loco about 4" behind the first one, oriented in the same running direction. Consist it to the first loco. Open the throttle to 100%. Both engines will start moving and accelerate to full throttle. Select the second loco on the LH throttle of the DT402, and go into ops mode programming. Select CV 5 in ops mode and adjust the value in CV5 for the second loco so that it does not gain or lose speed relative to the first loco. Now turn the throttle down to 50%. Select the second loco on the LH throttle, and enter ops mode for CV6. As the engines are running, insert values into CV6 until the speed matches. Now turn the throttle down to speed step 1. Same process for CV2 in the second loco: select it and enter values to keep loco 1 and loco 2 the same distance apart. You're done. Write down the values for each loco somewhere or use a program like JMRI to store the information. John C.
