Monday, October 10, 2011

Missing in action but back again...

Things have been quiet on the blog for the past month as I have been off work looking after my wife Chris as she had a hip joint replacement, makes you suddenly feel old. She had been having increasing leg pain over the previous year and we put it down to sciatica as she has a bad back. Eventually we got her to see about it and after the usual weeks waiting to see the specialist he went through the roof and scheduled her for the operation on 6 October. Now that obviously didn't happen as he rang us two days after that first visit to ask if she could be in hospital the next day, it was that bad.
All is well now, she can manage quite well and I returned to work today but she won't be back to work for another month or two.
Although I was the apprentice chief cook and bottle washer I soon got things under control and managed to get into the garage now and again. My previous GSV sheep van chassis post  was done during one of these moments.
What have I been up to since?
Well, I have been playing with Decoder Pro and the Soundtraxx Tsunamis in my steam locos trying to extract more of the good stuff from them. I now have several locos that will chuff heavily as they move away and then the chuff will almost disappear as they start to cruise along. Also if they come to a grade they will start to chuff heavily again as the Tsunami senses the load coming on. Similarly if the chuff will drop away as they drift down a grade. All very satisfying and I want to point out that when the chuff drops to a drift and increases again I am not changing the throttle unless of course I was starting or stopping.
Here is a quick and rough video of the effects.
I had been trying to achieve this effect for some time and finally worked it out.
First up you need to put some momentum into the loco and as I use the NCE ProCab I used 6 in the 0 - 9 range accessible from the momentum button. I should also mention that the NCE command station can be set up to have half the momentum acceleration setting when decelerating or a one to one relationship, I use the one to one so acceleration and deceleration settings are the same if using the ProCab momentum button. Note that the use of the momentum button on the cab will overwrite any CV 3 and CV 4 momentum settings in the locomotive but I use the button to try to replicate the load that is behind the locomotive, I use a low setting of 2 or 3 for just the locomotive when running 'light'.
The difference this time around is that one of the BEMF CVs has to be set to 0, this is CV 212 which is the Motor Control Intensity CV on the Advanced tab, then CV 188 on the DDE tab (Dynamic Digital Exhaust) has to be adjusted until you get the right responses, this might come down to adjusting CV188 by as little as only one or two once you are in the 'ballpark' area.
It seems that CV 212 turns off BEMF to the motor as the response returns to being like a no BEMF loco but some sort of sensing of the motor load is going on so maybe it is only half turned off, who knows?
It really comes down to adjust CV188, test and listen, then do it again and again until you zero in on the right value. I found that around 60 was a good starting point.
Other DDE sound CVs also need to be adjusted and there is no easy way to explain this, just try it out.
Here is a link to my Decoder Pro file for my Austrains C36 set up for auto chuffing.
The down side of the auto chuff is that without the BEMF it doesn't keep in time too well and I installed a can chuff arrangement which is much more realistic.
And here is a link for the same C36 set up for a cam operated chuff (perhaps a subject for another blog).
It appears that as each model loco is a bit different that you may have to play with the CVs for your own Austrains C36 but have a go you might like it.
If you don't like it then just use Decoder Pro to reinstate your own settings (assuming the you saved them in Decoder Pro first.
Other locos I have done by copying and modifying the C36 file are 2 Trainorama C32s, and 2 brass D50s so it will be interesting watching at the next Bylong operating session when the boys start to run them.