Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

An old ad Daniel -

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All good points Jasper ... but I'll continue to list Thermal Energy Engines, as it seems entirely unreasonable to think that someone would build or alter a mold, and have that name molded into more than some 6,000 of them, if they never existed as some form of an entity, thus adding them as such an entity to the chain is entirely reasonable, while as corollary, it would be unthinkable deleting them from the chain of provenance, given the physical evidence extant!

Now, I am willing to entertain the proposition that they likely never sold a single unit under that name, and became, got bought up by, or otherwise changed names to Solar Engines, before any significant marketing took place, which is not uncommon in the small business world. Similarly, it is likely that they never possessed an actual business address under the Thermal Energy Engines moniker, and quite possibly never took out a business license under that name either.

It is fairly certain that we will never know the whole story behind the who, what or why of Thermal Energy Engines of Phoenix Arizona. However, we do have indisputable evidence that somebody thought that would be THE name to be associated with the updated Solar #1 Stirling Cycle engine in its infancy, and as such they will be included in my thumbnail history.

Please do feel free to create your view of this history, to conform to your own ideas, as we all must.

Now it is finally time to delve into the origin mystery surrounding the Solar #1 Stirling Cycle engine.

I have long thought that the Solar #1 must somehow be a descendant of the British built Davies Charlton Ltd. Hot Air Engine. Certainly the looks alone, right down to overall layout and even color scheme, scream relationship. And so I have always been on the lookout trying to find one of these rather elusive engines, at a price I could tolerate. It took a very long time, but luck finally smiled, sort of, and eBay provided an example that seemed in unusually good condition .... and on this side of the pond even.

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It is clearly a very low mileage example, but there is a reason for that, and a reason why it wasn't as expensive as I usually see them selling for either .... it was broken at one of the flywheel shaft bearing ears.

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I initially did think that a little JB Weld and perhaps a bit of brass tubing would resolve the issue, but upon receipt I found the situation to be irremediable if not wholly irredeemable ... but more on that later. If nothing else, it would provide me with a good example for dimensional examination and comparison purposes, and so it has!

Upon my initial examination, I was immediately taken by the fact that virtually everything about the Davies Charlton engine was notably smaller than the corresponding part on the Solar #1. Often not much smaller, but universally somewhat smaller in essentially every comparable feature that could be measured. This disappointed me to no end, as it was pretty well putting my theory of direct lineage down the drain, and was most certainly devastating to my presumption of the new American company having acquired the tooling from the old British company.

However, after checking comparative dimensioning on most all of the individual parts, I started taking some of the critical dimensions on the general layout of the overall design ... and low and behold, significant correlations were found in all of the key elements of the overall design layout. The length of throw between the power piston and the flywheel shaft, the distance between the flywheels and the distance between the center-lines of the displacer and power piston cylinder bores were exactly the same, as were the throw of the crank-pins on the flywheels. Another pair of dimensions that were critically the same were the screw spacing that mount the engine to the frame, and also that mount the frame to the base. There is no way that these critical design elements could have been created the same on two different units by coincidence, but must of necessity be elements of the same original design!

There is no reason for a new company, that is only generally copying the visual appearance of a pre-existing design (with some changes), would need to adhere to any of the specific layout dimensions, especially when changing the physical size of most all of the individual components in the process. Yet they did just that. Virtually every individual component of the Solar #1 is at least slightly larger than its DC counterpart, yet the key operational dimensions of the design have remained unchanged.

Let me now digress back to the damaged frame of the Davies Charlton Ltd. Hot Air engine, as that frame represents what I believe to be the key element in determining the lineage of the design of the Solar #1.

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As you can see, the original thought of a little JB Weld was made moot by the actualities of the condition of the frame itself. Clearly possessed of inordinate amounts of "sink and shrink", it is clear that this part was cast/molded out of a wholly inferior alloy, and likely with an inadequate process, for the purposes intended! The term "pot metal" fits what is seen here, though there are wide ranging specifics to various forms depending on alloy composition. The frame has some real weight to it, so I suspect that this particular pot metal is likely based on a lead/zinc alloy, and generally speaking those two metals do not get along with each other all that well. No telling what other metals may be thrown into the pot, either intentionally or as contaminates, but clearly whatever is going on here is very wrong! Interestingly, though the base is larger and thinner, it only shows some heavy flow and a little sink, but no obvious shrinking nor cracking, though it does seem to be made of a different alloy that is less dense, and may in fact be based on aluminum.

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A point to be noted concerning the base is the hand stamped lettering pressed into the underside reading "Made in Great Britain", as opposed to the Solar #1 iterations having raised lettering cast in.

So to wrap this entry up, let me say that I am now convinced that the Solar #1 is the direct descendant of the Davies Charlton Ltd. Hot Air Engine, and that I do believe the original tooling changed hands as well, and not just rights to the design. Here is my thinking on this:

Because the DC castings/moldings were made from pot metals that were prone to catastrophic failures, the new company would have chosen to rework the molds so that they could be used with pressure injected alloys of greater homogeneity and strength. In the process of having a machinist rework those molds all individual part dimensions would have necessarily increased, but the dimensional layout would have had to be retained, which would not be the case if entirely new tools were built. While clearly not a certainty, this is my surmise, and I now feel fully justified in that as I offer the following photo as proof of concept!

Here is my Davies Charlton Ltd. Hot Air Engine reassembled on a Solar #1's frame, and all I did to accomplish this was to drill out the screw holes in the engine web and base to the next larger size (approx. .020"), from the DC self tapping 5-48 to accommodate the Solar #1's frame drilled and tapped 6-32 holes ... locations were an exact match!!!

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