I want to convert the McDonald Steel 777 over from air throttle to mechanical throttle, and am looking for the throttle bracket and arm to connect the governor to the linkage coming up from the deck. The linkages are still intact from the control stand to the last linkage but this bracket and arm is missing.

Anyone have a spare?

Maybe get one 3D printed, have a pattern made, and cast one?

We have 2 RS1's in Michigan you are welcome to come take measurements if you like to reproduce a fabricated one.

Not sure if they have air or mechanical though. Both locos are not near me so it may be awhile before I can check for you.

RS1's would tend to have different governors, and electric (MU style) throttles.

Jeff

Earlier RS-1s had an SI governor, replaced in later production with the PG. Both used the mechanical linkage on a single unit. The same governors were used on MU versions, with a throttle operator (AKA 'grasshopper motor') replacing the linkage. This operator was mounted below the governor and had three solenoid valves and air cylinders, and some bars and fulcrums. An arm connected to the input lever on the SI or PG, replacing the rods and bell cranks that ran under the cab and running board.

This is not the same PG governor that, say, a Geep would have, with A,B,C, and D valves within the governor. Funny thing is that EMD did use an arrangement similar to the Alco/GE one on earlier units, perhaps the FTs, but later units had the throttle operator valves and hydraulic cylinders within the governor.

Trust me on this; I've had three RS-1s and am familiar with both configurations. In fact, I was gathering the final parts to convert a unit, now for sale, to 27 pin MU and 26 air when "vandals" set it on fire.

EDITED a bit later- RS-1s, and the rest of the Alco 539 'clan', were offered as single units and with MU. An RS-1 does not automatically have MU, and a switcher isn't always a single unit. That MU was 19 pin; I know of a few railroads that would run mixed consists of RS-1s and 539 powered switchers.