Dave and Sam would make Leonardo feel like an artless slacker.

Roy,

You are correct in that all these factors will make the cab look big. I have tried to make all of the dimensions true to the prototype, but it still looks big. In the photo that I took from the same angle of the Gurley at Fullerton Train Days, the proportions look acceptable. Maybe the "big cab", "little boiler" look is caused by the fact that I am looking down at the model and we usually look up at the actually Gurley. What ever the reason, I am going to make a 2" boiler and do a comparison. We can take a polls of Burnslanders to weigh in on if we go 1) acuarate and a little funny looking or 2) artistic license.

not that I'm trying to second guess or nit-pick or anything...

but I agree the cab looks a little big...

looking at Preston's drawings, the top lip of the steam dome is approximately the same height as the lower roof line of the cab...and on the model (at least in the side view) the steam dome is noticeably below the roof line...
also the top flange of the tender tank should be just past the half way point of the cab windows, and on the model the tank flange appears just below half way up the windows...both those things would make the cab appear too big

in my personal modeling I will almost always choose what "looks right" over absolute correct dimensions...sometimes something just doesn't look right when compressed to model size

Its just one of those things that annoys me. You build part of the model, exactly to specs, as well as the rest of the built to exactly to specs, and one part looks way off! I know you're probably tempted to change the size, but stick with it, it'll look right once more details and parts are added on.

It's your engine, and you have to live with it; make it accordingly. You've already been straight about where you diverge from strict fidelity to scale.

Question: what part of the Princess boiler is 2" in diameter?

Also, not that I'm complaining, but I have noted some discrepancies in the C.K. Holliday drawing. I'd give greater authority to photos.

Praytell, what "discrepancies" have you found?

I believe the only problem is that your cab mock-up is slightly too big. Keep the boiler as-is, and reduce the size of the cab as necessary.

No, thanks. I'm really not complaining about it.

Roy, I wish you would not have modified your response, as I would have liked to address it.

As you mentioned, the drawings you used were second-generation. Since I haven't seen the drawings, I can't address your issues. I recall you mentioned "callouts" and measurements of the pilot wheels, and that you used pixels to measure them. You have to remember, the drawings aren't blueprints.

Drawings can be different from the real thing. Allen Brewster's 1973 Model Railroader drawings of the D&RGW K-27 were (and are) considered masterpieces, and models continue to be made from them to this day. However, in laying his drawings over broadside photos of the real thing, discrepancies can be seen--including his boiler diameter being incorrect.

Again, we should recognize that drawings for model building aren't blueprints. However, I can tell you that the Disney drawings in question were based on actual Disney drawings of the equipment, to which numerous details--all based on photographs--were added. We also used photographs to verify accurate proportions between parts. I doubt you will find any errors in the proportions of the various components and parts of the engines.

Some details--like the check valves on the Holliday drawing, which represent the first style used in the 1950s--were left as-is, for variety, while on the other engines, we used the Lunkenheimer check valves. Our drawing of the Ripley features a flange oiler just to the left of the first driver--a detail that was there at one time, but later removed. Does that mean the drawings are "incorrect?" Hardly. So of course, when it comes to details like this, modelers should utilize photographs from the era they're attempting to model.

I have concluded that Steve is right. The cab needs to be narrower. Thanks to all for the helpful comments. I will adjust the dome and tender heights, but the boiler will remain 1 3/4", true to the drawing. Here is the "Big Cab" looking from above.
[img]http://i390.photobucket.com/albums/oo345/CPTRR/Gurley-Kimball/Gurley026.jpg[/img]
Here is a modified cab, also looking from above, made narrower with front doors open. The verticality of the open doors helps to make it "feel" less wide and in fact it is less wide.
[img]http://i390.photobucket.com/albums/oo345/CPTRR/Gurley-Kimball/Gurley027.jpg[/img]
Now we can compare a photo of the model taken at a similar angle to a
photo of the Gurley
[img]http://i390.photobucket.com/albums/oo345/CPTRR/Gurley-Kimball/Gurley028.jpg[/img]
[img]http://i390.photobucket.com/albums/oo345/CPTRR/Gurley-Kimball/2008-05-03086.jpg[/img]
This is good. The narrower cab will also help to expose a thin edge of diamond plate just above the red trim stripe.
Concerning cab construction, I think that I am going to use a "sandwiching" technique. I am not very good at painting trim on windows. I found that when modeling the Retlaw 1 coaches, painting the red trim in place never produced a satisfactory result. What did work was pre-painting strips of styrene red and then gluing them onto the inside. Using this idea, I will make a 3 or 4 part "sandwich" of each of the sides of the cab. These will be painted before gluing them together. Here is a little mock-up to test the best method of gluing. The biggest issue will be the appearance of the edge at openings.
[img]http://i390.photobucket.com/albums/oo345/CPTRR/Gurley-Kimball/Gurley030.jpg[/img]
[img]http://i390.photobucket.com/albums/oo345/CPTRR/Gurley-Kimball/Gurley029-1.jpg[/img]