Bachmann Online Forum

Discussion Boards => Large => Topic started by: mudhen on June 19, 2010, 02:14:40 PM

Title: Steam chuff
Post by: mudhen on June 19, 2010, 02:14:40 PM
Just added a reed switch and two magnits to the tender wheels of the 1st of (2) K-27's. It sounds amazing and it is almost 1/4 ered perfectly to the drivers. It GREAT. Wait until I double head them with the echo in my back yard. It's to much.
Title: Re: Steam chuff
Post by: Doneldon on June 19, 2010, 04:03:27 PM
muddy -

It sounds like you have a nice piece of work.  I hope you continue to enjoy it.

                                                            -- D
Title: Re: Steam chuff
Post by: Kevin Strong on June 20, 2010, 10:18:34 AM
I found there to be enough of a mismatch in the timing to be noticeable to my eyes/ears with just two magnets on the tender axle, so I bit the bullet and put 4 trigger magnets on the rear driver axle. I just located the two wires coming from the plug that triggered the chuff, cut them, and wired in the magnetic switch instead. (Don't ask me which ones they were.) I ran a line of two-sided tape around the rear axle, and stuck the magnets in place. I then covered that up with another layer of tape to hold everything in place. Works like a charm, and no fussing with glues.

I've got a few other locos that I use magnets on the tender wheels or automatic (not triggered by wheel rotation) chuff. For some reason, them being "off" isn't quite as noticeable or objectionable as it was on my K. Perhaps it's just the size of the locomotive that draws it out.

Later,

K
Title: Re: Steam chuff
Post by: Udo on June 21, 2010, 11:25:59 PM
Hello together !
I get a little confused about this topic....
Why you don't use the "original" triggers in the cylinders of the K27 ?

I have two of them, equipped with ESU Loksound XL decoders. There I use the trigger signals supplied by the Bachmann PCB. Works fine....

In my 2-6-6-2, I have replaced the triggers by Hall sensors with 4 magnets on a drive axle. That works fine also.

Udo
Title: Re: Steam chuff
Post by: Kevin Strong on June 22, 2010, 03:49:19 PM
The K-27's optical chuff is apparently "backwards" to what many sound systems need in terms of triggering the chuff. You've got to hook the built-in chuff trigger to an interface circuit (a transistor or so) to get it to work properly. It's not a lot of work, but neither is wiring magnets and reed switches. I believe this was reversed in the 2-6-6-2 and Forney.

Later,

K