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DCC & Rivarrossi (anyone with experience?)

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  • Member since
    April 2003
  • 302,278 posts
DCC & Rivarrossi (anyone with experience?)
Posted by Anonymous on Tuesday, October 21, 2003 5:15 PM
Hi, I have a Rivarossi Big Boy and and Allegheny and have fitted them with Lenz decoders to run with a Lenz Digital-Plus.

They run OK - but not as well as I expected. The 4-8-8-4 is the same 'age' as the Allegheny so they both have the same, newer, Rivarrossi mechanisms.

I've just taken delivery of a Trix 4-8-8-4 and it's performance by comparison is AWESOME. I know it cost a lot more and should be very good but I really thought the Rivarossi equipment would be better.

My main gripe is the starting speeds. I've experimented with different settings - but I'm new to DCC - but can't seem to get them running nice.

It takes a lot of power to get them moving and when they start they start fast. Once running they can be throttled back to a slow speed but I just can't get a nice slow take-off.

Has anyone got some experince of fitting DCC to these locos and what settings did you use to get good, slow starting speeds.

Incidentally, the Trix starts on setting "1" on the controller and c-r-a-w-l-s better than anything I've ever seen!

Any help advice appreciated

Spence
  • Member since
    April 2003
  • 302,278 posts
Posted by Anonymous on Wednesday, October 22, 2003 11:06 AM
This is from the NCE D13SR decoder directions....
(this is what I have in my Rivarossi Y6b and it works well

There are five CVs that define:
-The voltage at which the motor starts
-How much ‘kick’ the motor gets to start it turning
-The maximum speed
-The response characteristics or ‘speed curve’.
-The frequency of the drive pulses to the motor

Start Voltage - CV2 (Vstart): Before programming the start voltage we recommend programming
CV65 (Kick Start) to zero. Kick start is used to overcome the ‘stiction’ of the motor by giving it a
voltage ‘kick’ when starting from a stop. We don’t want it getting in the way of setting Vstart.
We prefer using Operations Mode Programming (Program on the Main) to set CV2 so the
locomotive is just able to maintain movement at speed step 1. You can also use the programming
track... it just takes a bit longer to find the right setting for CV2.

Kick Start - CV65 After the start voltage is set . Program CV65 to provide a smooth and reliable
start when you advance the throttle from stop. The high frequency drive pulses of the D408SR act
more like smooth DC voltage than the low frequency pulses of a standard decoder making it harder
for the decoder to overcome that starting ‘stiction’ of the motor. This is why the Kick start CV is
needed.
If the value is too low the motor will not start moving reliably, too high and the locomotive will lurch
or leap as it starts.

Vmax - CV5: If your locomotive runs too fast you can use CV5 to lower its maximum speed.
Setting CV5 to 255 uses the maximum possible voltage to run the motor when full speed is
requested. Set CV5 to a smaller value to reduce the top speed. A value of 128 will yield
approximately ½ full voltage to the motor at top speed. 192 will provide about ¾ full voltage. All
speeds from the middle speed step to the maximum will be proportionally reduced (see diagram). If
CV5 is set to 0 the decoder will use 255 for maximum speed. Always make sure CV5 is greater
than CV6 to avoid erratic operation.

Vmid - CV6: CV6 determines how the motor responds through its middle speed ranges to
advancement of the throttle. If you set CV6 lower than half the maximum speed you’ll have smaller
increases in motor speed through the lower speed ranges. Then, as you hit the upper speed
ranges there will be larger increases between speed steps. In the diagram below you can see this
best illustrated by the factory default line. If you set Vstart larger than 0 you’ll will most likely want
to raise Vmid so a reasonable slope is maintained in the ‘speed curve’. If CV6 is set to 0 the
decoder will use 127 as the value. Setting CV6 to a value of 70 will approximate the speed curve of
older NCE (and Soundtraxx) decoders
Voltage
  • Member since
    April 2003
  • 302,278 posts
Posted by Anonymous on Thursday, October 23, 2003 2:36 AM
Thank you very much for this effort. I will try it out this weekend. Spence

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