Southern Pacific Cab Forward by Key Model Imports

Erik C Lindgren posted:

AGHRMatt posted:

Beautiful model. Great photo work, Erik. Is that bridge shot the module project you guys were working on?

Yeah Matt!

In this view I still needed to add smoke pellets...  

...

Nice.

I decided to dust off some bridge drawings I have to build a photo platform module. The bridge was built by Pacific Electric in 1913 and I can remember when trains ran under then backed across it to serve a steel plant on the north side (left) of the bridge. The City of Torrance had issued a Request for Proposals (RFP) to rehabilitate/retrofit the bridge. It actually appears on the city seal and was deteriorating. The RFP included  a very good set of drawings which I downloaded. I contacted the City yesterday to find out how the work turned out and they sent me this photo.

Erik - the technical side of that is the eccentric crank is probably loose, and will cause great grief during an operating session.

Eccentric cranks aim more or less at the axle center bore.  They are about 15 degrees off to impart motion to the eccentric rod.  A loose eccentric will ultimately wind up in an over-center position, bending the rod or worse.

Shaft Loctite is your friend.

I agree - your photographs are works of art.  If production runs can be considered art, then this model qualifies.

Looks like a really nice model. Enjoy.

I can't tell from those photos if the eccentric crank is in the right position or not. To me the latest shot on the bridge looks to have the rods down and the crank at an angle.

Nobody does smoke better than you do, Erik.  My hat is off!

I missed this thread the first time.

I'm always blown away by your photography.  Key sure did their part with a beautiful model.

Check the second photo of the very first post.  The eccentric is off by almost 90 degrees.  It is surely loose.

Okay, yes. I read too quickly and thought you were saying there was a general builders flaw in all of the positions of the eccentric cranks.

Great stuff. I probably will never see the finished version in person but at least I got to see the brass version they were hauling to shows some years ago and it was incredible.

I really like to have at least 2 versions of any locomotive I have even if it is by different importers. I have 2 versions of these locomotives and Key Model Imports has negated any reason to get anymore with their SUPERB versions. I want their ''Big Boy'' and their Santa Fe 4-8-4s. No doubt,both will be INCREDIBLE! 

The eccentric crank is not loose...that's how it was positioned on those locomotives.  Recall, it is a locomotive running backwards (perhaps someone with a greater mastery of valve gear can explain why the eccentric crank is lagging, not leading).

mark s posted:

The eccentric crank is not loose...that's how it was positioned on those locomotives.

I don't think so, Mark. The position of the eccentric crank should not have any bearing on either forward or reverse movement of the engine. The position of the block within the link, determines valve position and length of valve stroke, no matter the direction of movement. 

 Recall, it is a locomotive running backwards (perhaps someone with a greater mastery of valve gear can explain why the eccentric crank is lagging, not leading).

Well, Mark is partially correct - some locomotive operators wanted the radius rod to be down in normal operation, so Baldwin rigged the cab forward engines for reverse running.

But look again at that photo - the crank is a quarter turn away from any reasonable setting, forward or reverse.

Somebody help me on this - this crank is way, way out of normal position.  Plenty of prototype photos exist to back me up.

Yes Bob2, I saw the now removed photo, the crank was pointing at the tread instead of the axle.  It's not a complaint against Key or Erik, it's just something the owner needs to check before running it and it causes problems.

Gene Anstine

Well, I keep forgetting to hit the "post" button after I hit the "add photo" button.

Here's a photo.  Note that, in addition to being set up to run backwards (crank set toward front of locomotive, not front of engine), the crank bolt that holds the rod is completely contained by the driver center.  That is, it is roughly 15 degrees from a centerline from crankpin to axle center.  

Oh - and the photo is still there - #2 in Erik's initial post.  I would repeat it here, but I cannot grab it without repeating the entire post.  iPad inflexibility, I guess.

Bob, you are correct. In the second photo, there is no way I see that the siderod gets to the bottom with things in the correct position. Case closed for that one.

Better get Gary to turn that thing before he runs it. I sent it back months ago. Who knows if he did it or not. I didn’t run it.. only put smoke pellets in it and turned on the whistle. Bob you should write Gary and tell him. 

Check the prototype cab forward photos on Key's website; the eccentric cranks are angled away from the cylinders, as opposed to the much more common posture of pointing toward the cylinders.  http://www.keymodels.net/id16.html                          Today's Soo Line #1003 2-8-2 has the eccentric crank pointing away from the cylinders, too.   This was a bit more common on the locomotives built in the approximate 1913 era, such as #1003. See photos of articulateds built in the 1913 +/- period......lagging eccentric cranks, not leading.

Eric's photo just above does portray the eccentric crank being in a rather extreme position; perhaps it is loose. But then, all of Eric's other photos look just the way cab forwards looked in operation, in photos of the period.

Have never heard a satisfactory explanation on why the eccentric cranks on some locomotives lag,  and on far more locomotives, they lead.

Number 90 posted:

Nobody does smoke better than you do, Erik.  My hat is off!

I agree, it's some of the better photoshopped real-life smoke effects on a model I've seen. I have noticed plenty of people in magazines (especially RMC) are doing it, but most do it very poorly. The lighting doesn't match the smoke at all and there are usually very well-defined borders between the smoke photo and the real model. These shots don't have that look (thank goodness).

This one, looked a little odd to me until I realized that I wasn't seeing the drafting from the end of the stack you'd expect from a locomotive at speed (not to mention the angle of the smoke for something that's supposed to be moving at all):

Thought not perfect, it's still better than most post-shot smoke digital effects I've ever seen.

I look at this shot and think back to when I heard that Phillip Anschutz was looking over the real loco at Sacramento in the museum one night, which led some to think he'd pondered maybe taking a page from UP's playbook and pulling that AC-12 out of there and getting her restored to operation. I'd rather have seen that happen than the 4014 restoration currently underway!

Me too!

Have never heard a satisfactory explanation on why the eccentric cranks on some locomotives lag, and on far more locomotives, they lead.

My explanation above was not satisfactory?

The other possible reason is Walschaerts gear on slide valve cylinders.  The intake ports are different, and a different motion is required.

Erik - Gary will spot it quicker than I did.  It will take him 30 seconds to fix it.  The guy is a genius with this stuff.

The other possible reason is Walschaerts gear on slide valve cylinders.  The intake ports are different, and a different motion is required.

Bob2 - a good partial explanation. or perhaps, full explanation !