Large Scale Central

Bachmann Annie valve gear variations: am I missing something?

Modeling
#1

I only recently entered the intimacies of the Bachmann Annies. 'Seen 'em, watched 'em, etc. Never owned an Annie until I received my on-sale G5 version chassis-only a couple days ago. (Which, BTW, I’m pleased with for $50 even though they didn’t get the right front driver mounted squarely, but I’ll get to that…)

Mine is, by choice, equipped with Walschaerts gear.

Now I’m looking into the Stephenson gear version. But I have none to handle personally, so am digging into on-line photos. The pictures I see are not close ups, but it appears that Bachmann chose to not bother with furnishing the model with a valve rod. Alligator crosshead, guides, decent main and side rods, … but no rod to simulate operating the valves inside the valve chest.

Am I seeing this correctly?

I know the Big Haulers had zip for simulated valve actuation.

Dennis

#2

Dennis Thompson said:
I only recently entered the intimacies of the Bachmann Annies. 'Seen 'em, watched 'em, etc. Never owned an Annie until I received my on-sale G5 version chassis-only a couple days ago. (Which, BTW, I’m pleased with for $50 even though they didn’t get the right front driver mounted squarely, but I’ll get to that…) Mine is, by choice, equipped with Walschaerts gear. Now I’m looking into the Stephenson gear version. But I have none to handle personally, so am digging into on-line photos. The pictures I see are not close ups, but it appears that Bachmann chose to not bother with furnishing the model with a valve rod. Alligator crosshead, guides, decent main and side rods, … but no rod to simulate operating the valves inside the valve chest. Am I seeing this correctly? I know the Big Haulers had zip for simulated valve actuation. Dennis

There isn’t much to see externally with Stephenson valve gear. Here is a picture of a prototype Baldwin 4-6-0 with Stephenson valve gear. Most of the mechanics are inside the frame rails. [center]

(http://freightsheds.largescalecentral.com/users/sparkyjoe/_forumfiles/Baldwin-4-6-0-worked.jpg)

[/center] Here’s what you get with an Annie w/Stephenson valve gear (scroll to page 4) http://www.bachmanntrains.com/home-usa/dwg/dwgs/81099.pdf

#3

Joe:
Terrific photo; thank you for taking the time to post it. It shows exactly what I’m asking about that Bachmann appears to have left out. The, “missing,” valve rod can be seen in your photo just above the 3 brass crosshead guide oilers for the top guide. Runs into the valve chest to operate the valve steam admission inside. Not much to it. The left end connects by a rocking lobe and shaft that carries the fore and aft motion from the eccentrics all contained inside the frame. (Which is the part you talked about inside).

Years ago I never cared much about Stephenson Gear on models because there was so little motion/linkage to watch. Years later I walked up to a real locomotive similar to what’s in your photo, stuck my head a little inside the crosshead where I could actually see the eccentrics and valve gear. Pretty nifty I thought. After that I had more respect for that style of valve gear. If you are familiar with the MoLoCo Bear Harbor Gypsy locomotive, that model actually HAS working Stephenson eccentrics. I grew up around the Bear Harbor engine and when MoLoCo and I were sorting out what details were required for the model I pushed hard for working valve gear.

I’m thinking about getting a Stephenson Gear Annie. I really would like a confirmation whether or not Bachmann left out that valve rod. I think to simulate one would not be hard to do. Just want to know what I’m up against first.

Good thread; thank you,
Dennis Thompson

#4

Dennis, I believe you are correct. Bachmann apparently left off the valve rod! Here is a blowup from their own illustrated parts diagram… [center]

(http://freightsheds.largescalecentral.com/users/sparkyjoe/_forumfiles/Bachmann-Stephenson-valvegear.jpg)

[/center]

#5

This prob won’t help, thought I had some better shots of the “Prototype” #12 I"ll continue to look around.

(http://freightsheds.largescalecentral.com/users/calenelson/Tweetsie/TweetsiePilot.jpg)

#6

Cale,

You are right, it is a good photo, but not for this thread. Dennis wanted to know about Stephenson valve gear. You picture shows Walschaert valve gear.

#7

Great illustration. That tells everything. I’ve never seen that before. I can see that the pair of brackets that go inward with peg-ends would be a benefit. Try to build up from that, then run a rod forward and into the valve chests. Likely that would be all a guy would need to do to make it look right.

That does it.

Thanks again, Dennis

#8

Dennis,

Glad to help.

#9

Thank you for this thread. I always wondered about the difference but never bothered to look it up. Between Joe & Cale’s photos that’s a good side-by-side comparison of the two types of valve gear.

#10
Joe Zullo said:
Cale, Dennis wanted to know about Stephenson valve gear. You picture shows Walschaert valve gear.
Yep ...:)...
#11

ok wrong one again, but too good not to post-thanks for the corrections btw

(http://freightsheds.largescalecentral.com/users/calenelson/Tweetsie/yukonqueen.jpg)

#190

#12

If you want a good example of the Stephenson valving, check out the Bachmann Spectrum 4-4-0 and 2-6-0. Having replaced the broken gears in these locos it gave me an education…it’s all there inside the frame.

Barry

#13
Quote:
then run a rod forward and into the valve chests. Likely that would be all a guy would need
What? You aren't going to make it work?

I’ve often wondered why someone hasn’t made a kit of parts to produce an oscillating valve rod.

Quote:
a good example of the Stephenson valving, check out the
My Accucraft live steam C-19 has a working example - let me know if you want photos.
#14

Pete:

I’d love to see a working model. Even the eccentrics?

Dennis

#15

The new Bachmann C-19 has fully operating Stephenson gear between rhe frames, and the corresponding vale rod oscillations, and so does the Climax, too. The C-19 is pretty hard to see, but the Clima is all out in the open. Looks great, too.

Also the Bachmann Shays ALL have Stephenson link valve gear.

tac