K-Line Shay

A number of the K-Line steamers got the chuff from the K-Line Cruise board, aka MDK-090.  As those were very prone to burning up, you'd have to find an alternative for the chuff.  There are a number of versions of the MDK-090 Cruise board and the software on all of them didn't include chuff outputs.  I know the Tank Engine gets it's chuff directly from the cruise board, and if there's no chuff switch on your Shay, I would guess it's very likely that it also generated the chuff signal.

Just to verify, the shay does get its chuff from its cruise board. John's chuff generator is probably your easiest option. Not much room for alternatives.

Pete

I figured it must if there's no chuff switch.

If they are also driving the smoke motor with the diode like the tank engine, you'll want my latest hardware version of the Chuff-Generator, I added a FET output for the chuff to eliminate any issues with the drive directly from the microprocessor output pin.  The FET would have no issue driving the motor and the chuff input to the R2LC, assuming you do have the diode isolation.

Thanks for the info and I agree that the chuff is from the cruise board as there is no switch for the chuff. I understand from the owner that the smoke did not puff but had a constant smoke so there is no diode in the system. I removed a wire from pin 17 on the R2LC and used it to temporarily install a reed switch and the chuff is working. So now I know at least I can use a mechanical switch to get a chuff but that doesn't make it right. How do I know if the new motor driver board is programmed for a chuff?