The Marx H0 0-6-0 - A Battery Powered Mystery

 The Marx H0 battery powered 0-6-0 is something of a mystery. As I previously mentioned, it apparently had a very short production and is considered rare by some. I am unsure where it falls in the Marx H0 timeline, though I suspect that it predates their battery powered 0-4-0 ersatz PRR Atlantic-like model. For all I know it came at the end, but regardless, it is rare. 

Which is sad, really. 

It is a nice, though very simple, model of a USRA 0-6-0. From an engineering standpoint, it is rather ingenious. 

They managed to cram a lightweight, low voltage smoke unit and bellows pump into the forward part of the boiler, with the motor located under the cab. The original motor in this one was damaged, so I replaced it with the closest approximation, a clone of the classic Mabuchi F-130. This motor is slightly longer so some modifications to the back of the cab were necessary. 

By the way, the drawbar is being held in place temporarily by a brass paper fastener until I redesign the screw mount. 

For all its ingenuity, though, the designers failed to consider weight. Even with all this shoved into the plastic boiler it still remains very light. 

At 4.34 oz, its weight is similar to the cars it would be hauling. Bear in mind this is after I replaced the original motor, which was even lighter. Compare this to the weight of one of the 0-4-0s, in this case a rubber band driven one.

That additional 2.3 ozs actually makes a significant difference. The weight on the 0-4-0 is distributed over just four wheels, whilst the lighter weight of the 0-6-0 is spread out over six. Put this way, the tractive weight per wheel on the 0-4-0 is approximately 1.66 oz whilst the 0-6-0 has 0.72 oz, less than half. 

Another problem is the width of the treads.

The 0-6-0 has very scale like wheels in this regard, but for such a lightweight model this is a detriment. It derails very easily. You can also see another problem here - the tin used to manufacture the frame is extremely thin. It was already bent at the junction between the motor area and the rear driver, and in the process of removing the motor I caused the beginning of a stress fracture. I used a small length of heavier tin and glued it into place the sturdy things up (I chose not to solder for now, pending any future work).

The question remains as to what to do. 

I hesitate to do too much in the way of improvement to this model. It is too unusual, the only other Marx H0 steam locomotive that was very scale-like. There is also the issue of its apparent rareness. There is nothing pressing here in terms of what my "line" needs. There are better USRA six wheeled switchers out there, though the only one I can think that might be of similar vintage is the Rivarossi model (something I need to investigate). MDC made a six that was modeled on Southern Pacific switchers starting in 1949 that were very similar and appear to have been based on the USRA design.

If I want the model to operate reliably something needs to be done.The process of adding a slightly heavier motor that far back behind the last axle shifted the center of gravity enough that it derails far easier, even at 3VDC. Some weight needs to be added somehow, but the lack of space inside the locomotive is a huge problem. I do have lead tape from my model rocketry hobby that could be added in places, but at best that won't add enough. While the smoke unit in this model appears to be dead, I really don't want to remove it. The space in the frame beneath the smoke unit was considered, but in addition to serving as the air space for the bellows, there is once again the issue of working around that very fragile tin. More lead tape inside the boiler, perhaps? It would need to be a heavier stock than what I have on hand at the moment, and right now all hobby spending has been suspended because I need to eat for the remainder of the month.

Hopefully, I will figure something out. I would really like to see this six wheeler hauling revenue.