The online magazine on the history and operation of vintage scale model trains in American OO gauge

Friday, August 12, 2011

Remotoring my Original Scale-Craft 4-6-0

Back in 2008 I had a brief article on my original Scale-Craft 4-6-0. I had purchased it from David Sacks when I was in high school and it came to me looking terrible but running OK with a replacement motor. This article describes the two main motors you will see with this model (very late S-C had Pittman motors) and in another article I looked at how Sacks had re-motored the model. There are photos there but in short he hacked a Scale-Craft DC motor and gearbox up to leave only the gearbox and a portion of the drive shaft, and connected to that a DC motor of uncertain origin. The way to tell that it should have had the Scale-Craft DC motor is that the gearbox is inclined at an angle and also the weight was not cut to fit around the later Universal motor. Also it has most of the weight that should be under the DC motor still as well, a weight that would be left off if using the later motor.

This 4-6-0 may be seen running, badly, with the Sacks motor in the first of my videos. That motor and gearbox were on their last legs which was a big bummer as I wanted to run this model. However, I recently put one of the original DC motor/gearbox combos into a 4-4-2 model (on video here) and was very recently able to purchase yet another of the original motor/gearbox combos.

It took a bit of effort to tune up the motor but I am pleased to say this model now runs as smooth and quiet as the 4-4-2 and pulls well. This photo is of the visible, cab end of the motor, where the wires attach. Scale-Craft had a great little model out in the form of this 4-6-0 when it was introduced in 1937. I can’t imagine that anything else out in 1937 in HO or OO ran any better.

To describe this motor a bit more (also seen in this post), I have described to friends it as sort of a big Pittman motor but actually the design is pretty different. The magnet is split on two sides of the motor and the brushes are on the end away from the gearbox. It is not too hard to figure out but very different than any DC motor I have ever had to work on.

I have two more of these motors but they are the version with no built in gearbox. I also however have two DC style gearboxes that were “liberated” from the original DC motor by prior owners. I hope to get at least one more of these operational and in a model. It will be a challenge, though.

A final point is that this is a 24 volt motor, but at 12 volts it runs plenty fast for a 4-6-0 on a local freight and I have no worries about overloading it. But this may get at why it seems to not have been a popular motor with later OO gaugers, the top speed is relatively low. I always think it feels like it is running about 1/2 throttle when it is actually full throttle. Nevertheless, I am happy to have this model running well again, a sentimental favorite of mine that should log many more miles around the layout.

UPDATE: It runs even better in "large scale" mode on my power pack.

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