Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Timing is easy.

Just place the crank arm vertically. (straight up or straight down)

Then set set the eccentric so the high point is extended horizontally all the way forward or all the way back.

It is just a matter of having the eccentric 90 degrees to the crank shaft.


Regarding that screw on the side, it should be tight and it serves only to hold the outside disc in place which is just there to keep the eccentric straps from falling off.

Gil

How is the eccentric sheave attached?   If it has straps around the sheave, is the sheave welded to the axle/shaft?      If it was, it would always be fixed. That’s where my confusion is. How does adjusting that pulley change the timing (movement of the eccentric in relation to the crank).