Southern Valve Gear

[BClemens]

Drawing of a Baldwin 8-10-D with the set-up of Southern Valve Gear.

[BClemens]

Almost ready to make more parts...

[BClemens]

OK, so no interest in something other than what the a kit may include? Beans!

BC

[Dave_Johnson]

Did not know you were offering a kit.

[BClemens]

Very sorry to mislead.... I use the word 'kit' wrong. I use it to mean 'whole thing' and I must stop the alternate meaning. But I will most happily help anyone wishing to incorporate Southern Valve Gear on an engine. The system is not really 'kittable' nor can it be premade and simply applied to an engine since basic crucial dimensions must be taken into account; even driver diameter and of course the steam port dimensions including lap. Again; sorry to mislead.

[Builder01]

So, you are showing us these drawings because this is what you are going to build?

David

[Bill Shields]

I am currently working on a 1" loco with Southern and appreciate what you are showing.

Have you finished the final design of the bell crank, which has a critical dimension (or two)...which as you say, makes the VG not 'kittable' since each loco will be a little different.

[Fred_V]

I took on a project last winter to take a partially built engine and make it run. It came with Southern gear and was started 15+ years ago by Enos Yoder who used this gear on all his engines. My first time to work on this gear. Here is a link of it running on air. I don't know how to make the video show on screen.
https://www.youtube.com/watch?v=d83GLY_zXsc

[Bill Shields]

that's cool. I have a working example of the gear that I am going to use -> but because of some minor differences between center of piston and valve seat surface, have to re-design the gear.

One thing that I have learned is that as the suspension moves up and down, so does the valve timing. I had not thought about this (previously) because the engine that I am using as my example, runs perfectly square all the time - fwd or back, any cut off.

What I found after close examination, is that the main driver suspension sits on an upper stop so that the only possible travel is DOWN in the even of something really serious happening on the track. Otherwise, the main drivers just sit there and the rest of the engine works around them, keeping the valve events really square.

What included angle did you use on the bell crank = 15 degrees?

[BClemens]

There is a 'set back' of 0.300" on the valve rod arm of the bell crank. That is 76.1°for the bell crank angle. In mid gear, the bell crank arm attached to the transmission yoke is horizontal. This will move the valve the bridge width (in mid gear) so there are events enough to continue to run the engine without any load or grade - 'linked up' all the way to mid gear.

This is still a layout toward actual working parts. The thought was to redraw this in gear (FWD or REV) at 45° increments of full revolution to check operation and parts clearances. There is a "record KXL Macro" for continuous movement in this software but I haven't tried it yet. I'm just showing this for those who know and appreciate the amount of work involved - even in CAD. Lots of 'English' sometimes.

BC

[BClemens]

A bit more progress... when bored, I add bushings and fillets....

[Bill Shields]

so you bell crank angle as I would describe it is 14.9 degrees....close enough to 15 degrees for negotiation(s). The original drawing(s), which are not the clearest, appear to show either 15 or 16 (runny ink on the vellum)...