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Slow Locomotive

Started by taxmahon, January 19, 2017, 01:07:07 PM

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taxmahon

I have a Bachmann Southern Pacific 4449.
In DC mode it runs great. In DCC mode, it is slow and unimpressive.
What can I do to speed it up?

richiy

#1
You need to fine tune the decoder.
What DCC system are you using?
Below is a link to the decoder CV's. I don't use this decoder so no idea on fine tuning it.

http://www.bachmanntrains.com/home-usa/images/44913_Decoder_IS.pdf

richiy

Hunt

It is normal for a locomotive to run slower DCC vs DC power pack.

Example - With DCC motor gets about 12 volts DC at full throttle vs around 16 to 18 volts DC from a DC power pack. Thus the locomotive will run 25% (12/16 = .75) to 33% (12/18 = .67) slower using DCC vs DC.


Flare

Quote from: Hunt on January 19, 2017, 04:21:58 PM
It is normal for a locomotive to run slower DCC vs DC power pack.

Example - With DCC motor gets about 12 volts DC at full throttle vs around 16 to 18 volts DC from a DC power pack. Thus the locomotive will run 25% (12/16 = .75) to 33% (12/18 = .67) slower using DCC vs DC.


Doesn't the voltage depend on what system is being used?  My DCC system uses 16v.

Hunt

Flare,
A locomotive speed depends on the voltage available to the motor all other applicable factors being the same.

Locomotive will run faster using DCC system "A" than DCC system "B" if DCC system "A" voltage available to the motor is more than "B" 


Flare

Quote from: Hunt on January 19, 2017, 08:56:00 PM
Flare,
A locomotive speed depends on the voltage available to the motor all other applicable factors being the same.

Locomotive will run faster using DCC system "A" than DCC system "B" if DCC system "A" voltage available to the motor is more than "B" 



That's what I thought, thanks.

Piyer

Quote from: taxmahon on January 19, 2017, 01:07:07 PM
I have a Bachmann Southern Pacific 4449.
In DC mode it runs great. In DCC mode, it is slow and unimpressive.
What can I do to speed it up?

In addition to what the other posters said, it's also possible that in DCC mode the decoder is programmed to operate the locomotive at a more realistic scale speed. Thus, "unimpressive" might equal 80 scale miles per hour, while "runs great" might equal 150 smph.

The prototype, if Wikipedia is correct, was designed for a top speed of 110 mph, so if you are so inclined, you could adjust the speed curve to match that - presuming that its top speed on DCC is slower than that. The JMRI program mentioned by another poster would make that easier to do. Or you could leave the speed as is and benefit from it making the layout feel bigger and (hopefully) the reduced likelihood that she'll take a curve at speed and join the Flying Steam Corps. ;)

~AJ Kleipass~
Proto-freelance modeling the Tri-State System c.1942
The layout is based upon the operations of the Delaware Valley Railway,
the New York, Susquehanna & Western, the Wilkes-Barre & Eastern,
the Middletown & Unionville, and the New York, Ontario & Western.

richiy

I was never concerned with this.
I used the below link for determining speed. Even a three foot section of track and stop watch will work.

http://www.mcr5.org/articals/speed.php

A Google search for the average and top speed of my loco gave me what I needed to know.

richiy