I had heard that the sign for the Marion steam shovel near here had finally gone up - I helped with the artwork for it last year, including the cutaway view showing the internals as well as cleaning up the old photos. Went out this morning for a look:

A closer view:

Everything is looking real nice Ron!

Dave

This is a great blend of 3D printing along with excellent machining. It appears seamlessin the photos.

gerrit

Hi, I am a retired (68) Toolmaker/Machinist/Fitter & Turner, that started in GMH (General Motors Holden) in South Australia; pre-computer. I have many interests in all things in the engineering spectrum, but, Steam & aero engines are up the top. I am not into models myself (i'm a die-hard petrol head motorcyclist), but love looking at other peoples projects. especially when making things smaller that work!
Regards, Clodey.

The handle is only inserted to move the pawls, then its removed before starting the engine. There are holes all the way around the light blue disc, so they can pick a convenient one when they want to change the pawls. There will be a brake band in the groove on the far side of the pink drum, to hold the drum from moving when changing the pawls.

Ah... THAT's what I was missing!  The handle doesn't stay in place, and you don't change the position of the pawls on the fly. They're either engaged or not, when you start things up.  OK, that makes sense.

Besides, changing the engagement of the pawls on the fly seemed a little iffy without some kind of clutch mechanism there.  Seems like the ends of the pawls would get chewed up - or the inside of the yellow wheel, or both.

Makes a lot more sense this way!  Thanks for the explanation, Chris!
Kim