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Saturday, October 12, 2019

The Scale-Craft 4-6-2 -- not an easy model to build (or rebuild)

For several years I’ve been working on this beauty, a Scale-Craft 4-6-2. A prewar model, it was sold in two versions (more here) in OO and O scales. I have, of course, the OO gauge version.

My model is made of from major parts obtained in three separate purchases: the boiler, the tender, and the frame/drivers. Yet other parts came in various parts purchases. Working little by little I got it to the point seen here. Shiny and black! But it was not easy….

The major parts of this model are all sand cast in bronze, it is quite a model really, and quite heavy. It is based on the SP P-13 design, but modified somewhat, most obviously visible with the oversized cab and small drivers. The model was originally developed by H. L. “Red” Adams (more on him here! A good read!) and subsequently added to the S-C line, with some of the drive parts utilizing elements of their 4-6-0 model (and look at the last photo in the Red Adams article just linked, it appears to me that the boiler was modified a bit by S-C, and in particular the cab extended a bit more than in his original castings, to accommodate their motor).

Starting at the back with the Vanderbilt tender, the body is a single bronze casting with a smaller bronze casting for the rear frame and coupler mount. The other parts are stamped brass and brass. The one I obtained was set up with all the holes drilled to pick up all power from the tender wheels and to have a rectifier in the tender, just like the setup for the 4-6-0 with the Universal motor. I first built it up for the DC motor (more on that in a bit), but then reworked my installation to make use of a rectifier and the big AC Universal motor. For better operation I used NWSL wheels in the S-C trucks, they roll great and pick up power great, but only from one side. For the other side I modified the S-C wiring scheme with the AC motor to pick up from the other rail on the engine side, and use an insulated drawbar. I tried my best to smooth out the castings (still visibly a little rough after quite a bit of sanding), and I had to tap some of the holes. Completely assembled the whole things weighs a whopping 1 pound 10 ounces.

The boiler is a big, heavy casting that by itself weighs 1 pound 11 ounces (for comparison, the Nason Hudson boiler weighs in at only 1 pound 3 ounces). The cab is oversized in length (and maybe width) to accommodate the big motors used by Scale-Craft. I’d rate it a very nice casting, and came to me having been on a built up model. To the boiler various parts are fit, among the most obvious the being the big pipes. Of course, it is all simplified compared to the prototype, but I did work my boiler over reflecting on the prototypical layout of the parts as seen in my copy of the 1944 Model Railroader Cyclopedia and a set of Scale-Craft O gauge 4-6-2 drawings (I have yet to find a set of the OO instructions). Due to the large casting I used a torch to add my parts. The boiler front is a separate casting, also in bronze.

Then we get to the frame and a tale of a whole series of complications in building up a working drive. Originally, I should mention I had only the frame, no wheels, but was able to buy a frame with wheels and valve gear, saving me a lot of effort, although I think the model would look better with bigger drivers. I first set up the drive with the big DC motor and its transmission. I had to modify the bottom of that transmission and the mounting holes, but I got it on and then the boiler would not fit. I puzzled about this for a while, then finally drilled a new hole in the cylinder block to mount the boiler further forward. It’s not prototypical, the cylinders should be centered below the smokestack, but there is no way to do that without grinding out a lot of material inside the cab/boiler. I’d rate this as a design issue/failing by S-C. Got it all running, even posted a short video in the Facebook group, then – the DC drive gave up the ghost. Gears chewed up, it had almost certainly been on the way out anyway, no practical way to fix it, the gearbox basically can’t be disassembled.

With all those holes there for the wiring for the Universal motor, I reworked everything, installed a rectifier, puzzled a lot, and got that big motor installed with its different gear box. Tried to run it, and the gears don’t mesh correctly between the drive and the frame. Need to be closer to each other. More puzzling.

The good piece of news is that the gearbox used with the Universal motor can be easily disassembled and repaired, and I have a few extras. So finally, I decided the best option was to work on cutting down the bottom of the gearbox to fit lower into the frame so that the gears would mesh.

Which brings me to right now, the model runs, the gears mesh but not great. I’m going to give the project a rest for now, but will eventually cut it down more, it is close! It will take the curves on my layout, which is the big piece of good news.

Overall though, I’d rate this model as being a fairly difficult model to build. No wonder S-C took it off the market, and no wonder it is somewhat rare. As to my drive issues, perhaps S-C shipped out the model with a slightly modified gearbox? Maybe the seeing the actual instructions would clear up some questions I have. But respect for the builders that completed these models back in the day, and if you have one, this is a model to treasure.

1 comment:

Unknown said...

Scale-Craft later offered this engine with the larger 4-8-4 drivers in its last run. Just FYI