Not so Cherry Switch

[Anonymous]

One of the first questions I remember asking of this forum was about the malfunctioning chuff on my Lionel E6 Atlantic.  I was advised the Cherry Switch had probably gone south.  With this in mind I set about looking into the situation.

With the body removed I found the cherry switch and also noticed it wasn't going to be a simple swap.  Seems one of the drivers would need to be pulled just to access the screws that hold the switch to the chassis.  Comparing the existing switch to a functioning one I found the E6's wasn't spring loaded the way it should be.  I guess whatever spring mechanism it used was broken, allowing the arm on the 70% angled switch to remain in a colapsed position.  This sent no signal to the chuff unit.  Since the arm moved freely, if the engine was run quickly the actuating cam would bounce off the colapsed arm now and again, causing an ocassional chuff.  Even though the switch was broken at least I knew the sound worked

Faced with tearing the wheel off to replace the cherry switch I came up with what I thought might be an easier alternative.  I cut a small piece of fridge magnet and glued it over the switch arm.  The magnetic pull wasn't enough to make the arm stick to the cam full time, only once the cam moved close enough to the arm did magnetic attraction move the arm, thus energizing the chuff.  I tested this jury rigged setup and had curious results

  The chuff rate was irregular at slow speeds.  Sometimes there would be short bursts of machine gun like chuffs and then momentary silence.   I chalk up this momentary silence to the magnet not always making contact with the cam...something I think I can fix by shimming the magnet closer to the cam.  At faster speeds the cam throw must increase slightly, allowing the magnet to attach on each cycle.

On the other hand when the chuff rate is consistant at higher speeds it's now giving me 4 chuffs per revolution.  Normally this engine only has 2 CPR.  What with the action of the cam attaching and dettaching to a magnetic free moving switch arm, the switch now cycles 2 times for every one cycle of the cam.  It's kinda hard to explain but try to imagine if you will. 

The Mad Professor bids you farewell while retrurning to his lab for more fine tuning and experimentation.   IT'S ALIVE!!!  IT'S ALIVE!!!

Bruce Webster