Chet wrote:
Hi Guys!
I run a 1/8 scale live steam locomotive.
While testing the vacuum brakes on my tender, I blew out the diaphrams
that activate its brakes.
The original unit was used as a vacuum advance for old-time carburetors
and is now an endangered species.
Anybody have success making their own from scratch?
If so, would you be willing to share the process?
Thanks in advance,
Chet (engineer of ANCR Mogul #9401)

Look at a cruise control throttle actuator.