Bachmann SD 45 top speed

[djconway]

I picked up a Bachmann SD 45 at the Amherst show 1-30.  It sounds OK but the speed tops out at 42smph. Are any  others seeing this? I've tried programing the speed tables and setting forward a d reverse trim but the best I've been able to do is get the speed up to 42smph. 

Anyone have better luck?

[peteski]

What decoder is in that thing? If it is the standard Bachmann decoder, it is very basic - no CV 2, 5, and 6, and no speed tables.  How fast does it run on DC (at 12V or max throttle)?

[nscaler711]

Soundtraxx...  Under "Soundvalue"

[djconway]

What decoder is in that thing? If it is the standard Bachmann decoder, it is very basic - no CV 2, 5, and 6, and no speed tables.  How fast does it run on DC (at 12V or max throttle)?

It is the stock Bachmann sound decoder, factory installed. Sound Value SoundTraxx - looking for more/better programming info.
I'll have to see if I can find one of my old DC throttles.  Usually test DC operations with a 7.5V power supply (with over 45 years of RR stuff in the basement I should be able to find something. )

More testing results later ---

[djconway]

Well got the OLD Control Master X out of hiding and ran some speed trials.
A little surprised by the curve but they were reproducible.

A little background:
Kato 11" radius curves with 12.5" straight connecting to make a 118" per lap flat oval.
Volt meter and stop watch, loco with 10 cars  and a caboose.

Ran the loco approximately 15 minutes to warm it up (cold basement).
Started by setting the CM-X to 12 volts, and timed the loco through 4 laps to get an average speed.  I noticed a +/- 0.1 volt fluctuation, that seemed to get less as time went on, CM-X not used since I went to DCC in '97.

Results in the attached table & graph.

[peteski]

Um, since this is a sound decoder (which I didn't know when I asked to try it on DC), the test is not very useful.  As you know (and verified now), sound decoders need a fairly high voltage to initialize before even starting to run the motor.  Non-Sound decoders OTOH should be almost transparent when running in DC.

I have an Athearn sound-equipped F45 loco which needs around 9V DC before it even starts moving and it needs around 18V to move at a decent speed (I didn't figure out the actual scale speed).  I haven't tried running it in DCC mode yet (got busy with other project).

I have never worked with the Soundtraxx decoder in that loco so I can't really commend further in its performance. I agree that it does seem rather slow.  Next thing to do would be to remove the decoder out of the circuit and try the loco as a pure DC model, but that would require some additional tinkering. Hopefully, before you resort to that, maybe someone who also owns this specific model will chime in with their experience.

[djconway]

I haven't popped the hood off this one (yet), but that may be the nest step. Clean, lube, look for binds, a general tune up.

Bachmann site isn't much help either, I can't find specific instructions for the SD45 sound loco.

[wcfn100]

Bachmann site isn't much help either, I can't find specific instructions for the SD45 sound loco.

Isn't it just a 'Sound Value on Board" loco?

http://www.bachmanntrains.com/home-usa/images/Sound-Value-Decoder-Quick-Start-Guide.pdf

Jason

[R L Smith]

My SD45 also has a noticeably slower top speed, although I have not measured it.  I ran it for a few hours during an Open House today, MU'd with a pair of Life-Like C424's that have TCS CN decoders in them. For whatever reason, those were the only ones in my stable that were closely speed-matched to the new Bachmann unit. I don't know if it is due to the decoder or if it a new motor / gear design that results in the slower top speed.

I found nothing useful on the SoundTraxx website other than the list of CV default settings.

Otherwise, I am highly impressed with the appearance and the details of the Bachmann SD45. Too bad they don't offer a non-sound version.

Ron