Matching chuff rate on HO 2-8-0 ?

[MarkInLA]

Anyone have a sure fire method to program 4 chuffs per each wheel rev on Spectrum 2-8-0 from slow roll off to top speed using CV 29 " User Loadable Speed Table" Cvs 67-94 ?I know how to unlock it and to put CV25 to 16..Plus CV116 rates..But is it possible to have it 99% perfectly in sync ?

[Doneldon]

Mark-

The only sure-fire way I know of to get four chuffs per revolution, regardless of
loco speed, is to have a cam or a magnet on a drive axle or wheel.

                                                                                                           -- D

[Thomas1911]

I have been able to get reasonably close by changing the speed table curves and adjusting the chuff rate CV.  As Doneldon said, the only way to get a 100% accurate chuff rate is to use a cam.  I may break down and install them on my locomotives before long.

[MarkInLA]

Welp, I see the writing on the wall ...So many have said a cam is the only way..So I guess I just have to accept the reality of this..Odd though, how/why does a non-Spectrum 2-6-0 not only have near perfect chuffs (and greatest headlight ever) and A Spectum 2-8-0 near impossible to match chuffs and have possible the worst headlight ever ?!! All I can think of is that the 2-6-0 is a newer product which was thus given a better decoder and headlight(s) not available when Connie was designed...Yes ? No?
I'm sure in the future all steam will have 'cam on board' just like hobby eventually adopted (Kadee) knuckle couplers replacing those horn-hooks we used to put up with in RTR models..Then, on-board DCC and DCC/sound made another sea change in the hobby.' Keep alive ' and cams will be common on-board features one day.
Thanks for responses,
Mark

[ryeguyisme]

It surprises me that Bachmann hasn't implemented a chuff exhaust cam on their sound locomotives, and I wonder on top of that if it were to easy to install it on already existing sound equipped locomotives. 

[rogertra]

It surprises me that Bachmann hasn't implemented a chuff exhaust cam on their sound locomotives, and I wonder on top of that if it were to easy to install it on already existing sound equipped locomotives. 

See this August Model Railroader, I think.  There's an article on installing a sound cam.

[Thomas1911]

I didn't think that the Tsunamis that come in the sound-equipped Bachmann locos are capable of supporting a sound cam.  Only the full-blown Tsunamis from Soundtraxx will.

[Doneldon]

I didn't think that the Tsunamis that come in the sound-equipped Bachmann locos are capable of supporting a sound cam.  Only the full-blown Tsunamis from Soundtraxx will.

1911-

I think you might be right on that.

This points to a couple of additional issues: Do all sound cams work the same? If not, there may not be a reason to have a generic "cam-on-board." And, do cam-driven chuff effects need AI to work correctly? There's no problem with a locomotive going at a steady pace. But an accelerating or decelerating locomotive will not have the same "distance" in radians on the drivers on successive rotations, and therefore not the same time between chuffs. To be accurate, the decoder will need to be able to "perceive" these changes and, in effect, predict how long to wait between chuffs. Or is that just being picky?
                                                                                                                                                -- D

[rogertra]

Try this link if you are interested in sound cams, you can Google for more information regarding sound cams, there's lots of hits on the subject.

Much easier than replying on here and  pretending I know what I'm talking about. 

http://www.g-m-e.com/new_page_1.htm


Google is your friend.

[GN.2-6-8-0]

Thanks for the link.......good to have.