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I have recently discovered the world of CVs and understand how to program each one, but am not sure of what to program each loco to; it seems very time consuming to try lots of different settings to get the balance right, so was wondering if anyone knew of any for any of the locos I have. I emailed bachmann customer services and found that the best setting for 32-076 (56xx) was Cv54 = 12 and Cv55 = 60. All others were left as factory set and a nice control is given. I don't know what these two Cvs do and whether it is just these 2 Cvs that have a major effect? Other locos I want to program include a Bachamann Hall, A Hornby Grange, The factory fitted Class 08 and Jinty from the DCC set, a Royal Scott and a Lima King. Most decoders are the lenz LE100 / Bachmann Maccoder.

Do decoder CVs have a standard accross different manufacturers if they are NMRA compliant?

Please Help!
 

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DT
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4,794 Posts
There are no rules on setting CV's. Look at our reviews and you will see DCC decoder CV recommendations. In the early reviews I even drew some nice graphs. These are made on experience and trial and error. You don't expect to see main line locos being overtaken by shunters do you. See the review and comments on the Class 09 shunter. We studied the speed of the actual loco and tried to equate it to CV values. I think that we sorted it out, but it took some time.

NMRA guidelines do not cover all CV's. For CV54 & CV55, there doesn't seem to be a consensus on use and settings. Lenz uses them for Stopping time in Push-Pull set-up (CV54) and Brightness of A and C Function outputs (CV55). ESU uses them for Back EMF control on their decoders.

With ESU LokPilot and Loksound decoders, the two variables CV54 and CV55 are used to adjust the back EMF effect.

The settings would depend on the specific motor used in the loco.

CV 54 Load control „K“-component of the internal PI-controller. Range: 0 - 80, Default: 32
parameter K Determines how strongly load control effects.
The higher the value, the stronger the impact on the motor.

CV 55 Load control „I“-component of the internal PI-controller. Range:0 - 80, Default: 24
parameter I Determines the momentum of the motor.
Motors with large flywheels of large diameter require
a smaller value.

From the LokPilot manual:

Adjusting Load control
The load control of the LokPilot V2.0 can be adapted
to different types of motors. The standard settings
match most motors very well but may have to be
adjusted for other models. This is particularly true
for coreless motors (Faulhaber, Maxxon) where we
recommend to set the K-value (CV 54) to a lower
value.

Parameters for Fleischmann
Locomotives with the traditional round motor by
Fleischmann should be programmed as follows:
CV 54 = 14 - 18
CV 55 = 20

Parameters for Märklin® high performance
motors

The 5-pole high performance motor by Maerklin®
(series 37xxx) is best suited for the LokPilotDCC when

programmed as follows:
CV 54 = approx. 20 - 25
CV 55 = 38

Parameters for coreless motors
CV 54 = approx. 4 - 10
CV 55 = approx. 3 - 8
 

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Just another modeller
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9,983 Posts
***All the important CV's are consistent across brands.

When I chip a loco (and I do hundreds over a year):

* test its OK, remove all capacitors 100% of the time and install decoder. I most often re-wire throwing away original Mfr wiring if its practical to do it - but thats just my preference. (actually I don't throw it - I de-solder it and give it back to the owner so he has it if he wants to return the loco to DC to sell it later)

* Run in for about 30 minutes each way if new - I actually prefer to have a load on the loco so I cheat. I put it against a block and let it run on the spot. This has an added advantage: If the manufacturer has over-blackened the wheel tread, and they often do, pickup will be a bit poor. Running on the spot for a while polishes the tread just where it needs to be polished for best pickup - and for best "realism" too, as the real thing has a shiny part to the wheel tyre!

* Normally I start at top volts = appx 3/4 of max, mid volts = 1/4 of max. This makes slow to mid control very fine, with more rapid acceleration available for the top end of the speed range. I almost never end up with more than 3/4 of top volts otential and often less - it takes surprisingly little voltage to increase speed a lot.

MOST of the time there will be little need to change CV's for Back EMF.....

To me the most important on loco tuning are CV 5 and 6 - CV5 is top volts and CV6 is mid volts. I adjust these next and on most loco's first produced in the last 5 years I usually find that this is all that needs to be done to get speed step one perfect.

The effect is to comprtess each of the speed steps into smaller "bites" and so refine control.

I occasionally have to adjust start volts, but very rarely and then only on older motors.

If this is'nt enough THEN I touch back EMF as per previous posts. Playing with back EMF without knowing what U are doing can give strange results. Be sure to take a note of the default settings before you play.

TIP: adjust ONE thing at a time and test.... then do the next.

Regards

Richard
DCCconcepts
 
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