Hornby 59/66 CV settings for slow running

QUOTE (upnick @ 23 Sep 2008, 16:16) <{POST_SNAPBACK}>An N gauge E - R Models Baldwin Sharknose loco i tested the other day has the similar characteristics ..... only moving forward around half an inch a time its as though the motor does a revolution and then pauses it runs better in reverse, fitted with a TCS M1 decoder, disassembled it and cleaned the wheels /contacts and chassis even though it a new no difference in performance, these models are known to be highly geared but it isnt responding to the control as a loco usually does.

Having seen Poliss's Baldwin fitted with a Digitrax board decoder it's a bullet train compared

How can i try setting the CV'S to improve it using procab and TCS M1

***Is it a back EMF M1?

if so, try this

CV2 0
CV3 10
CV4 10
CV5 170
CV6 100

this should lower top speed, smooth early acceleration steps, improve slow speed control for a frisky motor.

regards

Richard

QUOTE (Richard Johnson @ 23 Sep 2008, 15:16) <{POST_SNAPBACK}>***Is it a back EMF M1?

if so, try this

CV2 0
CV3 10
CV4 10
CV5 170
CV6 100

this should lower top speed, smooth early acceleration steps, improve slow speed control for a frisky motor.

regards

Richard

Hi Richard,
Many thanks for the information,
I am the one needing to increase the speed on the loco Poliss has his going very fast, the one i have is crawling at times ...... the TCS is back EMF though.

QUOTE (Richard Johnson @ 24 Sep 2008, 02:59) <{POST_SNAPBACK}>***Similar setting, but first do a factory reset then make a couple of changes:
CV2/3/4 as above
CV5 240
CV6 160

Richard


Hi Richard,

Many thanks,
The CV's worked
The loco responds well now speed step 42 giving a nice runner ..... it still sounds tight in the gears despite running in on DC before conversion, once the track is finished running for a while will free the gears up hopefully somewhat

QUOTE (eddscott @ 25 Sep 2008, 18:07) <{POST_SNAPBACK}>On these hornby/lima offspring rather than the pancake motor they've shoehorned a can motor in its place and this has one capacitor across the terminals. I cut it off and reset the CVs to default but both locos still stutter. I've left them with CV54 at 001 and CV55 at 030 and at step 1 on the powercab you can see the stutter but its quite faint and from 3 onwards its barely noticeable.

*** The stuttering you mention is the low quality motor cogging at slow speeds - its only 3 pole from memory.

I really don't think your back EMF settings are right for this motor. In particular you are minimising the back EMF assistance

Why don't you reset the bachmann decoder to default which is CV8 to 8 and do the same sort of changes I recommended to Nick - they may have the same effect for you, as they are designed to smooth the start of loco's and particularly the CV3/4/5/6 settings work to help motors that are a bit coggy.

The bachmann/esu decoder has a different number range in the CV's concerned so set as follows:

CV2 = 0
CV3 = 10
CV4 = 10
CV5 = 55
CV6 = 42

Then, if more tuning is needed play with back EMF.

When you play with back EMF change ONE cv at a time and note the effect. If you change two at a time you have no frame of reference to work with

CV53 = Determines the back EMF that the motor should supply at maximum speed. The more efficient the motor, the higher this value may be.
CV54 = Determines how strongly load control effects the motor - The higher the value, the stronger the impact on the motor.
CV55 = Determines the momentum of the motor Motors with large flywheels of large diameter require small values I suggest the hornby almost certainly needs a very high one!

first try the following: these are similar to the ESU defaults and are usually good with most motors. (ESU make this decoder)

the highest value possible in all these CV's is 64

CV 53 = 56
CV 54 = 32
CV 55 = 24

next try this (but I suspect CV54 is possibly too low)

CV 53 = 56
CV 54 = 20
CV 55 = 40

Yes... you can fiddle with CV55 a lot but only adjust in steps of 5 at a time upwards... it may need to go quite high
No....Don't at any time reduce CV54 too much - It controls back EMF effect strength and if you reduce it to a very low level, you are losing all the motor control advantage of back EMF and the quite coggy hornby motor needs the help!

Richard