Assistance with IM cab forward

Hey Guys,

I've been messing around with my cab forward. I put in a Digitrax DZ125PS decoder. The issue I'm having is: Throttle response. This thing has none. I set CV's 2, 5 and 6 per Digitrax's suggestion. CV-2= 026, CV-6= 128 and CV-5= 154. The locomotive doesn't start moving 'til about 45 to 50 on the throttle. Then from there to 99, there is no real decernable difference in speed. Oh- I have the 8 amp Super Chief(if that matters). This is the first run from IM. Any suggestions-? Have I missed something? I ran it on DC- same thing. I did go up with the values of CV-6 and CV-5. I set CV5 to 255-no change. I'm pretty new to this DCC thing-so I (of course) am still learning.
I know cab forwards were not race horses- but- I would like more throttle response. This thing is slow. I did oil it per the IM instructions.

Thanks in advance,
Wolf

 

The IM Cab Forwards have a really power hungry motor. It might just be that the Z scale decoder doesn't have enough "umph".

A bunch of us had this same issue when we tried the Digitrax SDN144PS Sound Decoder.

River_eagle found the best solution:

Does the DZ125 have BEMF control? You might look at those settings.

I have since replaced my SDN144PS with a Soundtraxx Tsunami for sound and a TCS M1 for motor control. It's simply perfect now.

 

Thanks Mark,
This is of big help. I think I have some of those TCI decoders. If so, I'll swap it out.

Thanks again,
Wolf

 

I have the same problem with low throttle response with an H0 scale Atlas (Four mode decoder) Silver B40-8. Maybe adjusting the BEMF is the solution for that, too? Is this common in other decoders, too?

Interesting thread.

 

Well this didn't work on my locomotive:

Originally Posted by river_eagle
...I set the BEMF CVs (55, 56, 57) all to zero, and speed and performance improved greatly.

So- next I'll switch to the TCS decoder. I have the plug version. The MC1. Cross my fingers and toes.

Thanks for listening,
Wolf