I ran the Hogwarts Express (actually a combo Express and Hogwart’s Freight and Ferry) at our club open house and it a huge sucess. However, The little 4-4-0 pulling it could not make it up the steeper grades so it was relegated to the top section where the kids had a harder time seeing it.
Anyway, so I figured to add my son’s 2-8-0 to the 4-4-0 to give it some umph and sound. But the 4-4-0 runs away from the 2-8-0. Litterally, on bump and the 4-4-0 disconnects and runs away at twice the speed of the Bachman.
So how do I adjust the two locos to syncronize them?
They control the voltage levels for starting, the mid step and the upper end, plus the acceleration and deceleration between the throttle steps.
CV02 is the starting voltage “boost”,
CV03 the acceleration rate (probably not your problem),
CV04 the deceleration rate (probably not your problem, either),
CV05 sets the maximum voltage (may be your solution),
CV06 set the mid-point voltage (may be part of your solution).
I’ll send you the excerpt from the Digitrax decoder manual for those.
SpaceMouse,
I’ve had some success with these CV’s. However, you have to have the decoders that have these available. For example, Digitrax DH121’s do not have CV05 and CV06, but the Digitrax DH123’s (and all “series 3” decoders) do.
Anyways, I start with CV02 (V-Start). MU both locos together (but don’t couple them) and gradually increase the throttle until one engine moves. Break the MU, and Ops Mode program the slow engine’s CV02 to a higher number (and write these down as you do them). It takes some “guess and check”, but get the slow engine to start at the same time the fast engine starts.
Next, MU both locos again. Hold both engines with your hand(s), and rapidly increase the throttle to 50%. Wait a second to make sure both locos are wound up to 50% throttle, then let them go. One will probably be faster. Break the MU. Now, you have a decision to make…which loco at 50% is the speed you like best? Which ever it is, either speed up or speed down one of the locos using Ops Mode programming with CV06 (V-Mid). Again, this is more “guess and check” than any real mathematical method.
Once you get them to match at 50% throttle, do the same as above except at 100% throttle using CV05.
At this point, with the start voltage, mid-point voltage, and max voltage all matching, your locos ought to run reasonably well together. If one loco is changing speeds too rapidly (causing the locos to buck agains each other when you are increasing or decreasing the throttle), then you can play with CV03 and CV04 (the momentum).
No problem Chip. And after reviewing Paul’s post and thinking about the scope of this, it sounds like yet another chunk of information for my locomotive roster and database! Never thought model railroading would start taking up gigabytes.