Are there different gearing between models?

[BlueFox]

I have a new Bachmann #60306 Conrail GP40 that I have broken in with about 3-4 hours of running.  I have noticed that it doesn't run as fast as any of my Bachmann FT-A's or B's or Bachmann DDA40X's.  Is it geared lower than any of my other locos, possibly for pulling power rather than speed?  As of now I can't run it in a consist with any of my locos.  I've tried all the settings of CV's for speed, voltage to no avail.  Anyone have any ideas?

Frank

[ACY]

Why would you want to run a GP40 with a DD40 or FT anyways?
To answer your question locomotives often have different gearing or motors which can make it difficult to consist them.

[jward]

while an ft-dda40x combo is extremely likely, a gp40-dda40x combo isn't. remember union pacific had run through arrangements with both the western pacific and c&nw. both roads rostered decent sized fleets of gp40s. from a prototype standpoint, the only drawback to such an arranement would have been the different gearings  between the two types. the dda40x's were FAST. they were geared fast, had special circuitry to make them accelerate faster, and had horsepower to burn.....adding any other type of locomotive to a dda40x would only serve to slow the brute down.....

[Jim Banner]

If you want to run a GP-40 with a DD40 or an FT, go right ahead.  It is your railroad.  In real life, these locomotives were near contemporaries anyway, built within a couple of decades of one another.  Not much different than running GP-38's with F7's which was quite common on local branch line service up to 1990 or so.

In order to run them together on DCC you need to have CV2, CV5 and possibly CV6 implemented in the decoders.  Set CV5 in the faster locomotives to slow their top speeds down to the top speed of the slowest one.  Then set CV2 in all of them so that they all start at the same throttle setting.  Then run them at about half speed.  If their speeds are different, adjust CV6 on the faster ones until they are all the same.  The speeds do not have to match perfectly but should be close enough that no wheel spin occurs at any speed when they are coupled together.  Oh, and don't forget to shut off BEMF control while matching speed and running in a consist.

Jim

[BlueFox]

Thanks, guys, for the info.

At the time of the comparisons all I had on-hand to compare with the GP-40 were a couple of FT-A's & B's and 2 DDA40X's.  My other loco's were at the local MRR club and not available for the comparison.  I have no intentions of running the GP-40 with the DDA40X's or FT's at all.

With more running time on the GP-40 its starting speed has smoothed out and it is faster, somewhat, but still has some minor jerkiness to it at the beginning of start-up (could this be due to the decoder Bachmann uses?)  I've tried playing with the CV's but this didn't fix the jerkiness, nor the 'humming', at start-up.

BTW, I had to add a strip of eletrical tape to both sides of the metal frame that goes up into the hood area to get rid of the ratteling noises it made right out of the box (it was B-A-D!!!)  It is much quiter now and hardly makes any ratteling noises.  I plan on getting a few more of these models (now that I know how to 'tweek' them) so I can make up a consist of them together.

Frank

[Doneldon]

some minor jerkiness to it at the beginning of start-up (could this be due to the decoder Bachmann uses?)

Frank-

Almost certainly.

           -- D