Slow Speed

Discussion in 'DCC & Electronics' started by willist, Dec 31, 2006.

  1. willist

    willist New Member

    I have a Lenz decoder in my Bachmann 2-8-0. It has very good slow speed acceleration, and very good gradual braking. My problem is top speed is very slow, what can I do to increase top speed? What CV do I need to program?
  2. Fluesheet

    Fluesheet Member

    Willist, did your decoder come with documentation? If not, check here:

    It looks like it is CV5. An alternative is to build a user loadable speed table (which requires changes to 28 CV's for the speed, and a change to CV29 to tell the decoder to use the user table).

    I hope that helps!
  3. willist

    willist New Member

    Thanks for your reply. I've changed CV5 to 0, now I can a more realistic speed. I can actually exceed the speed that a 2-8-0 would have actually gone, but at least now I can run closer to a scale 35 to 40 mph. :thumb:
  4. Fluesheet

    Fluesheet Member

    Glad to help!
  5. KCS

    KCS Member

    Well, not to jump the gun but models are built somewhat like the real thing. Gears have a reduction ratio. Smaller locomotives has smaller reductions because of their size to move heavy load under slow speed and larger locomotives pull load under faster speed. I know I am wrong but someone please correct this for me because it's new years at 1:30 am meaning I've had a few to drink so you know what that means lol. Someone will know what I'm really trying to say. :)
  6. nhguy

    nhguy Member

    Changing CV5 to 0 is fine but that takes the top speed voltage cap off of the CV. Next time put it on the Programming track and read what is in CV5. Then you can adjust it up to raise the top speed. This CV controls the voltage to the motor at the full top throttle speed step. Putting a value of 0 just nullifies this CV.

    If you happy with 35-40mph as a top speed, then put it on the Program track and read what is in CV6 the mid voltage CV. You can then go to CV5 and add 50% of the value of CV6 into it. This will give you a top speed in CV5 and make it functional again. If the value you put in still seems too slow you can add to it in the POM or ops mode to get the top speed you want. Try that and see what happens. I put a top speed on all of my engines using CV5 because they all run to fast at the top speed step.

    My choice for switcher is no more that 25 mph, my road swtichers and freight engines no more than 40-45 mph and my passenger engines 80 mph. I use CV2, CV6 and CV5 to adjust this.

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