Weaver I-4 Pacific no chuff

Bill,

This was the issue that @harmonyards fixed on my Lionel Boston & Albany U-3b 0-8-0 switcher - the chuff switch. I don't know whether Weaver's I-4 uses mechanical actuation of the chuff switch or electronic actuation from a flywheel tape and sensor as done by MTH. Engine looks great. I hope you enjoy it.

MELGAR

I purchased one new from Weaver. Although mine chuffed. Every now and then it would miss one of the 4 chuffs. Seeing it was new and the Springfield show was coming up. I delivered to Weaver’s booth and they shipped it back a week later and it never did it again. Note in box. Stated they adjusted the chuff switch. This came with ERR cruise.

Hi Dave, Thanks for offering me that information. We didn't know if the chuff was from a chuff switch or and electronic device. We can at least look to a mechanical switch. Pat Norcross modified a Weaver Berkshire I had and at that time he adjusted the chuff switch. At least we are on the right track. Thank You.  Best Regards, Bill Park

Mine always missed the same chuff. 2 chuffs, skip one, then 3 in a row then miss again. I figured it had a 4 lobe cam on the engine. I thought maybe the profile of one of the 4 lobes was slightly different where it was always the same one. I guess there’s some wiggle room with the bracket to tweak the adjustment.

The only way to “ adjust” these is tweaking the bracket, tweaking the arm on the cherry switch, or in worst cases, actually grinding a high spot off one or more of the cam lobes,…..I’ve had to do all 3 on Weavers in the past to make them reliable …..best way to set these up is on the bench with a meter, …..make  4 reliable short beeps forward and reverse …..I usually disengage whatever drive mechanism so I can rotate the cammed axle by hand  and play with certain spots where I’m having an offense,….( no beep, broken up beep, too long a beep, etc,.) …when using a meter, you’re looking for 4 nice clean short beeps ……that’s what will give you those nice defined exhaust strokes….

Pat

I have this engine. It is my best steam engine. I have not had any issues with the chuff.

Based on Harmonyards comments above, if I do experience this problem, it will be time to install Gunrunnerjohn’s Chuff Generator and Super Chuffer.

@ctr posted:

I have this engine. It is my best steam engine. I have not had any issues with the chuff.

Based on Harmonyards comments above, if I do experience this problem, it will be time to install Gunrunnerjohn’s Chuff Generator and Super Chuffer.

While John’s equipment is an option, the cherry switch on cam system is pretty reliable …..no need to reinvent the wheel if the system already exists,…..especially when there’s already a four lobe cam…..it’s a very simple system to diagnose…..all the cherry switch is doing is make or break a connection to chassis ground…..

Pat