Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Model & Toy Steam Engines – Stirling Cycle – Flame Lickers – Small Antique Originals => Topic started by: Stoker on August 15, 2020, 06:30:59 pm
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It appears that the Red Frame portion of the Solar 1 engine may offer the best easy visual guide to which era an engine truly represents, in the early years of production.
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Type 1 frame; If you will note that in the photo above, the engine frame farthest away is the Davies Charlton Hot Air Engine Frame.
Type 2 frame; The frame in the middle is numbered in the 56xx range, and is from an engine with a Thermal Energy Engines - Phoenix Arizona, and also found with Phoenix Arizona - Solar Engines without an R (in circle), marked bases.
Type 3 frame; While the bottom frame is representative of everything produced more recently than that, including Phoenix Arizona - Solar Engines with an R (in circle) and Made In USA - Solar Engines with an R (in circle)= PM Research, Wellsville, NY.
Notable similarities and differences:
1.) The DC frame is cast in a mold showing very little if any pressure injection, is rife with flaws commonly associated with low grade pot metals, such as sink, shrink and fractures to the point of crumbling. It is made of a rather heavy alloy that likely has some fair percentage of Lead and Zinc, but is probably lacking much in the way of Tin, as that would have tended to allow for better performance. Just guesses as to composition really, but somewhat educated guess for all that. Likely, this one's frame flaws is an anomaly, and not representative of overall production, but the process and materials are clearly marginal, even when they more typically produce better parts. There are no ejector pin marks evident on this frame, which again speaks to a low pressure, likely gravity feed, molding process, that may better be described as enclosed casting. While the flywheel bearing "ears" are prominently buttressed on the outside surface, the inside is just a straight wall. The engine mount surface is 1.00" above the base and has two small holes, possibly molded in that accepted self-tapping 5-48 screws about 1/2" long, and just 1" apart. The holes for the flywheel axle bearings are .312" diameter located 1.110 above the frames base. The holes in the bottom of the frame for mounting to the base plate are also sized for self-tapping 5-48 screws, spaced along the center-line of the frame 2.5" apart starting about 5/16th of an inch from the axle end of the frame.
2.) The TEE frame shows marked evidence of superior materials and process, showing a perfectly filled surface without any signs of sink, shrink or structural flaws. There are now apparent, four pronounced ejector pin marks on the reinforcement ribs which form an "X" in the inside bottom of the frame, strongly suggesting transition to an actual closed pressure injection process, using superior alloys that are much stronger, lighter in weight and more cohesively packed out, better filling the mold. Oddly, while the engine mount surface remains 1.00" above the base, with the same mount hole spacing, the "ears" are now a bit lower, with the center-line of the flywheel axle just 1.070" above the base, probably caused by a determination that with the new materials and process the base of the frame didn't need to be so thick anymore, which turned out to be a mistake requiring shims be placed under the frame to lift it off the base far enough to clear the flywheels, whose diameters had been increased as well, but more on that later. The screw holes in the bottom of the frame for mounting to the base plate are also still at 2.5" spacing, but start about 1/8" further from the axle end of the frame, though some variance is noted, suggesting that these holes or pilots for them are not molded in, but rather drilled and tapped (6-32) in a second operation, likely fixture controlled, but often those fixtures allow for some deviation in set-up.
3.) The final frame configuration offers all of the upgrades featured in the previous listing, and the same mount hole sizes and spacing's, but corrected the too low height of the flywheel axle bearing holes so that shims would no longer be required for flywheel clearance on the base. A feature that was added at this time was an inner buttress to the ears, thus slightly thickening the ears, the draft of which suggests that the cavity in the mold was deepened using an EDM process. This inner buttress is a key diagnostic for this latest generation of frames.
Note:
There are some exceptions to these observations so far noted, that will be dealt with in a follow up post.
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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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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 5,000 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.
Stoker: As this is , as others in this thread have mentioned, your “Bible” or “doctorate” I understand this is your “view of history”.
I have never written a Bible, but I have done thesis and dissertation, and even I founded a business. I will leave this thread before I get cancelled, or the thread again get’s locked. But as parting thoughts may I proffer the fact that I just acquired a Solar #1 engine, with matching serial numbered Ross book and frame #61** , and a Dec 1977 letter signed by John I. Griffin, with “Thermal Energy Engines Phoenix Arizona” on engine base. To me , 6000+ of these didn't need to be made to number this one as another entity , the simplest conclusion (Occam’s Razor) to me is that it was consecutively numbered with my other 1977 Solar Engine. Two bases and a few differences, one company.
(https://i.postimg.cc/5NRvM1hn/03-BA36-E5-2-BD9-4-FFA-A3-E6-3-E0-A66-B80-F49.jpg)
(https://i.postimg.cc/Y9nh480f/C655524-C-D5-D3-4-C97-83-C2-587-F935-D7375.jpg)
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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.
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Stoker : you present an excellent amount of thought and research on the Solar #1.
I hope to not offend , but I humbly state that I do not concur with some of your conclusions.
Foremost, may I point out that there is yet no evidence presented that any such company is now known, or has been known, as Thermal Energy Engines of Phoenix Arizona.
The markings on a metal base stating “Thermal Energy Engines Phoenix Arizona” (note absence word ‘of’ ) do not necessarily mean there was an incorporated company by that name.
A USA registered patent , or trademark, or better yet the essential Arizona business incorporation and associated Phoenix business address would go far in proving such a company existed. The people at the US Internal Revenue Service are quite sensitive in getting taxes paid on even such a thing as a mundane toy engine, and therefore the IRS does insist that a company have contact info and addresses where tax money can be squeezed from said such company.
I have done a superficial search of 1970’s Phoenix census records, 1976-77 Phoenix & Maricopa phone books, and 1975-78 Phoenix business directories and have yet to find any Thermal Energy Engines listed. BUT my search results are very limited by scattered internet databases. It once was a good source of data research to simply call a local Phoenix library to see if they could assist, but the current virus plague has severely limited that route. You may have better luck than me, and thus you may yet prove the existence of TEEPA.
For now, at this early research stage , may I suggest the Occam’s Razor research principle “entities should not be multiplied without necessity” ?
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An old ad Daniel -
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Very much looking forward to when you can find more time away from work Jan.
As I'm sure you have noticed, there is a whole lot of blank space available in the first several posts .... and you are just the person to fill much of it, with anything that you may choose to share with us here.
I am definitely hoping for .... and looking forward to, any and all help that your deep knowledge and collections can provide!!!
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What an amazing thread this, great initiative Daniel!!!
Couldn´t think of anyone more knowledgeable, to make a thread on this subject :)
I will study this "bible" as it evolve, and offer what details i might have, when/if something strikes me as missing.
Have some hope, that i once the workload wears off, will find the time to properly scan my ephemera here, and share with you to use here or elsewhere as you see fit.
Ps.
Congratulations on baggin´ that fantastic looking Davies Charlton engine.
Am looking forward to your conclusions, now that you finally have the "dna-string" completed.
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Looking forward to revelations about the Davies Charlton "grail"!
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What an interesting read Daniel. You've written a Doctorate on the magnificent little Solar #1.
Got a start going, but have a long way to go yet, and will need significant help to get there .... but thanks for the kind words!
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What an interesting read Daniel. You've written a Doctorate on the magnificent little Solar #1.
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Okay, this thread is back alive as I have unlocked it. Somehow it seems I locked it a few days back, but didn't mean to do so.
I am looking for anybody's input that can help provide details on the Inception, Evolution and History of this iconic model Stirling Engine, and the companies that made, advertised and marketed it. As posts come in, I will glean info from them and transfer it to the dedicated early posts at the top of this thread.
Eventually, or sooner, this will all get moved to the "Toy Steam, Scale Model, and Antique Engine References" Board, but for now I want more people to see it and hopefully respond with good information .... PLEASE.
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Gentlemen, yesterday I finally received in the mail, something I have been wanting for a very long time, and receiving it has brought revelations galore, but ultimately also what I believe can only be seen as actual confirmation of long held theories.
It will take me a day or three to get all my work on this done to the point where I'll be willing to post it up, mostly photo taking and typing, but it will lead to some modification of my earlier posts in this thread.
Here is an image of this seminal acquisition:
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Very impressive stuff! It's made me revisit my TEEoPA engine with a view to sprucing it up a bit.
You stated, "Fuel cell cover has domed wick holder with no cylindrical extension, held in place by circular lock washer with inside "fingers" to act as clamp." I wonder if you have a picture of the fuel cell. My engine came without one, so I got a chromed faucet plug to fit the recess, but I don't know what goes under the plug.
Hope these views will help:
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I should add that the "dome" looks to be about the top 1/4 to 1/3 of a sphere, and certainly not a hemisphere. The base of the dome measures approx. .560 dia. while the lower stem measures about .340 dia. and the wick is about 3/16" dia. and an easy slide fit through the fitting.
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Very impressive stuff! It's made me revisit my TEEoPA engine with a view to sprucing it up a bit.
You stated, "Fuel cell cover has domed wick holder with no cylindrical extension, held in place by circular lock washer with inside "fingers" to act as clamp." I wonder if you have a picture of the fuel cell. My engine came without one, so I got a chromed faucet plug to fit the recess, but I don't know what goes under the plug.
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LINKS & REFERENCE MATERIAL
http://www.pmmodelengines.com/v1/wp-content/uploads/2015/09/PM-RESEARCH-MODEL-ENGINES-CATALOG-WEBSITE.pdf (ref. pgs 4-10)
http://steamup.dk/solar/solar%20engines.html
http://www.plans-for-everything.com/downloads/stirling_engines/ST%20RossBook.pdf
https://www.officeofsteamforum.com/general-discussion/stumbled-upon-a-vintage-solar-1/
https://ntrs.nasa.gov/citations/19830022057
https://strives-uploads-prod.s3.us-gov-west-1.amazonaws.com/19830022057/19830022057.pdf?AWSAccessKeyId=AKIASEVSKC45ZTTM42XZ&Expires=1598923382&Signature=JZ0%2BlZG7dqp10vCshsJLnkUaVKk%3D
https://www.tapatalk.com/groups/modelsteam/viewtopic.php?p=1156505#p1156505
https://www.gasenginemagazine.com/farm-life/exciting-news-for-stirling-hot-air-engine-lovers
http://modelenginenews.org/people/dc_ltd.html
This Solar Engines history sketch taken from early Solar Engines catalog/brochure:
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This PM Research history, copied from the Mini-Steam Facebook page:
"was incorporated in 1973 in Arkport, NY, by Gary Bastian and Paul Vossler. Their first product was a line of portable gasoline engine driven permanent magnet generators. In 1978 they moved to Wellsville, NY which is located in Allegany County and is the least populated county in the state. They later began fabrication and vacuum forming of plastic parts. In 1985 they expanded their building and decided they would like to give their children the opportunity to learn to run some of the shop equipment. This led them to design and make castings for a small model steam engine. Their original #1A aluminum engine was a replica of an 1880's steam drilling engine. This same engine is now offered as #1BI with bronze and cast iron castings. They made up some kits and headed to a local steam show, where they quickly sold out of everything they had taken. They decided to continue expanding this line with more model steam engines, boilers, and accessories.
In 1993 they introduced the EL-1, engine lathe kit. This was the beginning of their line of model machine shop tools which has grown to include an arbor press, bench grinder, crank shaper, drill press, milling machine, table saw and wood lathe.
In 1995 they purchased Solar Engines from Ed and Jeanette Morgan of Phoenix, AZ; and in 1996 they began production and marketing of the Solar-4 sun runner and other Stirling cycle engines. In 2006 they introduced the DYN-1 dynamo kit, Model 8M twin cylinder oscillating marine engine, and a line of model tapered pipe fittings. They currently have over 30 models and are continuing to develop new products.
Even though we know them best for their engine product line, they are also well known in the aviation industry through their line of radome boots and leading edge erosion protection tapes."
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OTHER ENGINES IN THE LINE-UP, PAST & PRESENT
Ditto ................
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LISTING OF ADS, FLIERS AND ASSOCIATED EPHEMERA
Earliest ad found thus far .... March 1978:
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Note that the engine base shown is that of the Davies Charlton Hot Air Engine with separate rectangular burner, and not the Solar Engines style built in round burner, along with small diameter cooling fins on displacer cylinder and fence not continuous all the way around engine, along with other features!
Next earliest ad found ..... July 1978:
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The image now is showing the correct Solar Engines base with built in round burner, large diameter cooling fins on displacer cylinder and fence is continuous around the engine, as well as other details consistent with the newly modified revisions to the engine!
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Full color, glossy, multi-page brochure showing several offerings in the line, and giving a brief history of the Hot Air Engine, probably from the mid-1980's.
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Also entered as a place holder for future additions .......
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SOME DIFFERENCES NOTED IN THE ASSOCIATED ANDY ROSS BOOK "STIRLING CYCLE ENGINES"
Inserted as a place holder to have details started soon .....
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CATALOG OF PHYSICAL DIFFERENCES NOTED
Seems it may be wise for me to log some of the observations that I made today, before losing track of all those details ..... which could happen any second now! ;c)
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Comparison of four generations of Solar #1 Stirling Engines.
A.) Davies Charlton Ltd. Hot Air Engine , Solar #1 Precursor
1.) Marked on underside of base in hand stamped sunk letters in two lines:
MADE IN
GREAT BRITAIN
2.) Has mailbox shaped burner/chimney housing mounted in hollow well at back of base.
3.) Separate rectangular burner is unvented without separate filler cap. Fills and vents through wide diameter wick port.
4.) No ejector pin marks anywhere on any of the parts of this engine.
5.) Power piston is short (.5" x .5") thin walled brass with flat top, without cannelure grooves and solid brass wrist pin with brass cone spacers.
6.) Fence railings are not continuous around the front of engine, with 45 degree inward bends at all terminations, those being toward the back of the engine, nearly touching the power and displacer cylinders and being bare exposed, while those in front of engine being nicely brass capped.
7.) The flywheels are just under 2" diameter allowing good clearance above base and from front fence post. Outer rim has been machined, inner rim as molded ~1.48" diameter.
8.) The frame is sized correctly to give flywheel clearance above the base without shims, but is very weak at the ears where the flywheel axle bearing holes are drilled. Bad pot metal and poor gravity feed "injection" of material only worsens the problem.
9.) Burner/fuel cell rectangular tank has a raise brass rim around wick hole about .60" I.D. x .75" O.D. x .125" tall, stuffed with wadded cotton.
10.) Slotted head self-tapping screws (5-48 x 1/4") holding engine to frame and frame to base.
11.) Displacer cylinder cooling fins exhibit poor fill-out and shorting around circumference, with an outside diameter trying to be 1.0" and mostly failing, while the diameter at the base of the fins is ~.80". The displacer rod is ~.155" dia. and has a larger diameter fitting on its end to accommodate the wrist pin connection to the flywheel crank arm. The power piston cylinder is ~.625" dia. and 1.3" length with a flat end closure end. There are no ejector pin marks or other signs of actual injection molding.
B.) Thermal Energy Engine of Phoenix Arizona, with the hand stamped I.D. number 56xx on the back of the frame:
1.) Marked on underside of base in even sized, raised letters that have been molded in two lines:
THERMAL ENERGY ENGINE
PHOENIX ARIZONA
2.) Chimney mount tab at 3:00 o'clock position around alcohol reservoir is drilled and tapped with a thumb screw for clamping cylindrical chimney.
3.) No vent notch / pry slot molded into edge of base leading to alcohol reservoir.
4.) Heavy ejector pin marks obvious on rib connecting power cylinder and displacer cylinder, even notching into displacer shaft bushing collar.
5.) Power piston is ferrous material with silvery look that has very fine cannelure rings that stop close to the piston skirt and the wrist pin, which is hollow with O-ring spacers. Piston is just under .50" diameter and 1.00" long with an under bore crown approximately .10" tall.
6.) Fence railings wrap around the inside of the first fence post closest to the displacer, continuing entirely around the front of the engine, while extending beyond the last fence post near power piston, and looping inwardly to form a tight free-standing "eye" at both ends.
7.) The flywheels are just over 2.23" diameter allowing no clearance above base without shims and little clearance with front fence. All increase in diameter has been in outer rim which is lightly machined, but inner rim as molded is same diameter as above, and continues same throughout all future production.
8.) The frame has to be raised off the base on washers (.060" in front & .030" in back) in order for flywheels to clear the base, and even at that there is hardly enough material at the top of the uprights, to allow material safe drilling of the flywheel shaft bearing holes. Washers used are same hard whitish plastic as used under pressure regulating screw. Frame is now pressure molded from good material, requiring mechanical ejection from mold.
9.) Fuel cell cover is essentially a chromed electrical knockout plug (which continues to present day), and has a domed wick holder with no upper cylindrical extension, held in place on lower cylindrical stem by circular lock washer with inside "fingers" to act as clamp. Holds a standard 1/8" woven wick.
10.) Slotted head screws (6-32 x 3/8") holding engine to frame and frame to base.
11.) Displacer cylinder cooling fins exhibit excellent fill-out and no shorting around circumference, with an outside diameter of 1.25" while the diameter at the base of the fins is ~.95". The displacer rod which is ~.184" dia. runs through a bronze bushing (oilite) that protrudes slightly from the displacer cylinder, while the rod does not have a larger diameter fitting to accommodate the wrist pin connection to the flywheel crank arm, but just has a slotted end to surround the crank arm. The power piston cylinder is ~.625" dia. and 1.3" length with a domed closure end. There are 3 witness marks of 1/4" dia. ejector pins on the web surfaces between the cylinders, one notching into the cylindrical boss of the displacer rod bushing, strongly suggesting injection molding processes.
C.) Solar Engines of Phoenix Arizona, with hand stamped I.D. number 61xx on the back of the frame:
1.) Marked on underside of base in two different sized raised letters that have been molded in with uneven spacing between the two lines:
PHOENIX ARIZONA
SOLAR ENGINES
It should be noted that the line "PHOENIX ARIZONA" is in the exact same position on the base, with the exact same size letters as found on the TEEPA engine above, but the words "SOLAR ENGINES" is formed of slightly larger letters and the whole line is skewed so that the left end of the line is further from the line above, and the two lines are closer together at the right end of the line. There is no letter R in a circle (indicating Registered Trademark), showing on the base of this engine.
2.) Chimney mount tab at 3:00 o'clock position around alcohol reservoir is drilled and tapped with a thumb screw for clamping cylindrical chimney.
3.) No vent notch / pry slot molded into edge of base leading to alcohol reservoir.
4.) Heavy ejector pin marks obvious on rib connecting power cylinder and displacer cylinder, even notching into displacer shaft bushing collar.
5.) Power piston is dark gray non-ferrous material that has fewer but coarser cannelure rings that stop further from the piston skirt and the wrist pin, which is hollow and ferrous with O-ring spacers. Piston is just under .50" diameter and 1.00" long with an under bore crown approximately .10" tall.
6.) Fence railings wrap around the inside of the first fence post closest to the displacer, while being clipped off flush with the last fence post.
7.) The flywheels are just over 2.23" diameter showing machining marks, yet allowing no clearance above base without shims and little clearance with front fence.
8.) The frame has to be raised off the base on washers (.060" in front & .030" in back) in order for flywheels to clear the base, and even at that there is hardly enough material at the top of the uprights, to allow material safe drilling of the flywheel shaft bearing holes. Washers used are same hard whitish plastic as used under pressure regulating screw. Frame is now pressure molded from good material, requiring mechanical ejection from mold.
9.) Fuel cell cover has domed wick holder with no upper cylindrical extension, held in place on lower cylindrical stem by circular lock washer with inside "fingers" to act as clamp. Holds a standard 1/8" woven wick.
10.) Slotted head screws (6-32 x 3/8") holding engine to frame and frame to base.
11.) Displacer cylinder cooling fins exhibit excellent fill-out and no shorting around circumference, with an outside dia, while eter of 1.25" while the diameter at the base of the fins is ~.95". The displacer rod which is ~.184" dia. that runs through a bronze bushing that protrudes slightly from the displacer cylinder, while the rod does not have a larger diameter fitting to accommodate the wrist pin connection to the flywheel crank arm, but just has a slotted end to surround the crank arm. The power piston cylinder is ~.625" dia. and 1.3" length with a domed closure end. There are 3 witness marks of 1/4" dia. ejector pins on the web surfaces between the cylinders, one notching into the cylindrical boss of the displacer rod bushing, strongly suggesting injection molding processes.
D.) Solar Engines of Phoenix Arizona, with hand stamp I.D. number 140xx on back of the frame.
1.) Marked on underside of base in two different sized raised letters that have been molded in with uneven spacing between the two lines:
PHOENIX ARIZONA
SOLAR ENGINES
It should be noted that the line "PHOENIX ARIZONA" is in the exact same position on the base, with the exact same size letters as found on the TEEPA engine above, but the words "SOLAR ENGINES" is formed of slightly larger letters and the whole line is skewed so that the left end of the line is further from the line above, and the two lines are closer together at the right end of the line. There is now a letter R in a circle (indicating Registered Trademark) off to the lower right about 1/4 inch, which none of the TEEPA engines have, while some of the earlier SEPA engines do not have it either.
2.) Chimney mount tab is not drilled and tapped for thumbscrew.
3.) Base is molded with slight notch along rear edge centered on alcohol reservoir to act as vent / pry slot .
4.) No obvious ejector pin marks noted on rib connecting power piston cylinder with displacer cylinder.
5.) Power piston is non-ferrous material with dark gray color with medium fine cannelure rings that stop closer to the piston skirt and the wrist pin, which is solid and non-ferrous with O-ring spacers. Piston is just under .50" diameter and 1.00" long with an under bore crown approximately .10" tall.
6.) Fence railings are cut off flush at first and last fence posts.
7.) The flywheels are at about 2.23" diameter and showing machining marks, but minimal clearance is established by rework of frame (see below).
8.) The frame is redesigned slightly to reinforce and lengthen the uprights that mount the crankshaft, providing more material to safely drill the bearing holes a little higher, offering more clearance between the flywheels and the base so shimming of the frame is no longer needed. Frame is pressure molded from good material, requiring mechanical ejection from mold. Standard frame from here on out.
9.) Fuel cell cap has one piece press fit domed wick holder that has cylindrical extension upward for better flame breathing. Holds a standard 1/8" woven wick.
10.) Philips head screws (6-32 x 3/8") holding engine to frame, but slotted head screws of same size holding frame to base.
11.) Displacer cylinder cooling fins exhibit excellent fill-out and no shorting around circumference, with an outside diameter of 1.25" while the diameter at the base of the fins is ~.95". The displacer rod which is ~.184" dia. runs through a brass bushing that doesn't protrude beyond the cylinder face, and the rod does not have a larger diameter fitting to accommodate the wrist pin connection to the flywheel crank arm, but just has a slotted end to surround the crank arm. The power piston cylinder is ~.625" dia. and 1.3" length with a domed closure end. There are now no witness marks of ejector pins on the web surfaces between the cylinders, and no notching into the cylindrical boss of the displacer rod bushing, strongly suggesting the use of a stripper plate in place of the ejector pins on this visible surface during an injection molding process.
E.) Solar Engines of Phoenix Arizona, with no hand stamp I.D. number on back of frame.
1.) Marked on underside of base in two different sized raised letters that have been molded in with uneven spacing between the two lines:
PHOENIX ARIZONA
SOLAR ENGINES
It should be noted that the line "PHOENIX ARIZONA" is in the exact same position on the base, with the exact same size letters as found on the TEEPA engine above, but the words "SOLAR ENGINES" is formed of slightly larger letters and the whole line is skewed so that the left end of the line is further from the line above, and the two lines are closer together at the right end of the line. There is now a letter R in a circle (indicating Registered Trademark) off to the lower right about 1/4 inch, which none of the TEEPA engines have, while some of the earlier SEPA engines do not have it either.
2.) Chimney mount tab is not drilled and tapped for thumbscrew.
3.) Base is molded with slight notch along rear edge centered on alcohol reservoir to act as vent / pry slot .
4.) No obvious ejector pin marks noted on rib connecting power piston cylinder with displacer cylinder.
5.) Power piston is non-ferrous material with light silver gray color with very fine cannelure rings that stop closer to the piston skirt and the wrist pin, which is solid and non-ferrous with O-ring spacers. Piston is just under .50" diameter and 1.00" long with an under bore crown approximately .10" tall.
6.) Fence railings are cut off flush at first and last fence posts.
7.) The flywheels are over-sized at about 2.24" diameter and showing ejector pin marks on inside of rim with no evidence of being machined on rims, and having very minimal clearance with base. Possibly mistakenly assembled with unfinished flywheels.
8.) The frame is redesigned to reinforce and lengthen the uprights that mount the crankshaft, providing more material to safely drill the bearing holes a little higher, offering more clearance between the flywheels and the base so shimming of the frame is no longer needed. Frame is pressure molded from good material, requiring mechanical ejection from mold. Standard frame from here on out.
9.) Fuel cell cap has one piece press fit domed wick holder that has medium height cylindrical extension upward for better flame breathing. Holds a standard 1/8" woven wick.
10.) Philips head screws (6-32 x 3/8") holding engine to frame, but slotted head screws of same size holding frame to base.
11.) Displacer cylinder cooling fins exhibit excellent fill-out and no shorting around circumference, with an outside diameter of 1.25" while the diameter at the base of the fins is ~.95". The displacer rod which is ~.184" dia. runs through a brass bushing that doesn't protrude beyond the cylinder face, and the rod does not have a larger diameter fitting to accommodate the wrist pin connection to the flywheel crank arm, but just has a slotted end to surround the crank arm. The power piston cylinder is ~.625" dia. and 1.3" length with a domed closure end. There are now no witness marks of ejector pins on the web surfaces between the cylinders, and no notching into the cylindrical boss of the displacer rod bushing, strongly suggesting the use of a stripper plate in place of the ejector pins on this visible surface during an injection molding process.
F.) Solar Engines of Phoenix Arizona, with no hand stamp I.D. number on back of frame.
1.) Marked on underside of base in two different sized raised letters that have been molded in with uneven spacing between the two lines:
PHOENIX ARIZONA
SOLAR ENGINES
It should be noted that the line "PHOENIX ARIZONA" is in the exact same position on the base, with the exact same size letters as found on the TEEPA engine above, but the words "SOLAR ENGINES" is formed of slightly larger letters and the whole line is skewed so that the left end of the line is further from the line above, and the two lines are closer together at the right end of the line. There is a letter R in a circle (indicating Registered Trademark) off to the lower right about 1/4 inch, which none of the TEEPA engines have, while some of the earliest SEPA engines do not have it either.
2.) Chimney mount tab is not drilled and tapped for thumbscrew.
3.) Base is molded with slight notch along rear edge centered on alcohol reservoir to act as vent / pry slot .
4.) No obvious ejector pin marks noted on rib connecting power piston cylinder with displacer cylinder.
5.) Power piston is non-ferrous material with dark gray color with medium coarse cannelure rings that stop closer to the piston skirt and the wrist pin, which is solid and non-ferrous with O-ring spacers. Piston is just under .50" diameter and 1.00" long with an under bore crown approximately .10" tall.
6.) Fence railings are cut off flush at first and last fence posts.
7.) The flywheels are now ~.050" smaller at about 2.18" diameter showing finish machining marks, thus offer better clearance for the flywheels relative to the base and fence.
8.) The frame is of the now standard improved type, to reinforce and lengthen the uprights that mount the crankshaft, providing more material to safely drill the bearing holes a little higher and along with the flywheel diameter reduction, offering more clearance between the flywheels and the base so shimming of the frame is no longer needed. Frame is pressure molded from good material, requiring mechanical ejection from mold.
9.) Fuel cell cap has one piece press fit domed wick holder that has very tall cylindrical extension upward for better flame breathing. Holds a standard 1/8" woven wick.
10.) Slotted head screws (6-32 x 3/8") holding engine to frame, but slotted head screws (6-32 x 1/4") holding frame to base.
11.) Displacer cylinder cooling fins exhibit excellent fill-out and no shorting around circumference, with an outside diameter of 1.25" while the diameter at the base of the fins is ~.95". The displacer rod which is ~.184" dia. runs through a brass bushing that doesn't protrude beyond the cylinder face, and the rod does not have a larger diameter fitting to accommodate the wrist pin connection to the flywheel crank arm, but just has a slotted end to surround the crank arm. The power piston cylinder is ~.625" dia. and 1.3" length with a domed closure end. There are now no witness marks of ejector pins on the web surfaces between the cylinders, and no notching into the cylindrical boss of the displacer rod bushing, strongly suggesting the use of a stripper plate in place of the ejector pins on this visible surface during an injection molding process.
G.) Solar #1 by PM Research, as is still in production.
1.) Marked on underside of base in two different sized raised letters that have been molded in with uneven spacing between the two lines:
MADE IN U.S.A.
SOLAR ENGINES
It should be noted that the line "MADE IN U.S.A." is in the same position on the base, as the earlier "PHOENIX ARIZONA", with the same size letters as found on the TEEPA engine and the SEPA engines listed above, but the words "SOLAR ENGINES" is formed of slightly larger letters. The skewing of the lines is no longer apparent, but the letter heights are still slightly different between the two lines. There is still a letter R in a circle (indicating Registered Trademark) off to the lower right about 1/4 inch, which none of the TEEPA engines have, while some of the earliest SEPA engines do not have it either. There is also now a silvery 1.5 x 2" stick-on label applied upside down below the molded in lettering, between the mount screws that has the Solar Engines profile image logo with a "TM", for Trade Marked, to the upper right. Below that image are the words:
SOLAR ENGINES TM
A Division of P. M. Research
Wellsville, New York
Made in U.S.A.
2.) Chimney mount tab is not drilled and tapped for thumbscrew.
3.) Base is molded with slight notch along rear edge centered on alcohol reservoir to act as vent / pry slot .
4.) No obvious ejector pin marks noted on rib connecting power piston cylinder with displacer cylinder.
5.) Power piston is non-ferrous material with dark gray color with medium coarse cannelure rings that stop closer to the piston skirt and the wrist pin, which is solid and non-ferrous with O-ring spacers. Piston is just under .50" diameter and 1.00" long with an under bore crown approximately .10" tall.
6.) Fence railings are cut off flush at first and last fence posts.
7.) The flywheels are now about 2.22" diameter showing finish machining marks, and now barely clearing the base, but still fair clearance to the fence.
8.) The frame is of the now standard improved type, to reinforce and lengthen the uprights that mount the crankshaft, providing more material to safely drill the bearing holes a little higher and along with the flywheel diameter reduction, offering more clearance between the flywheels and the base so shimming of the frame is no longer needed. Frame is pressure molded from good material, requiring mechanical ejection from mold.
9.) Fuel cell cap has one piece press fit domed wick holder that has very short cylindrical extension upward for better flame breathing. Holds a standard 1/8" woven wick.
10.) Slotted head screws (6-32 x 3/8") holding engine to frame, as well as holding frame to base.
11.) Displacer cylinder cooling fins exhibit excellent fill-out and no shorting around circumference, with an outside diameter of 1.25" while the diameter at the base of the fins is ~.95", but there is now a definite thickening of the triangular lateral reinforce web from the former .125" to .20". The displacer rod which is ~.184" dia. runs through a brass bushing that doesn't protrude beyond the cylinder face, and the rod does not have a larger diameter fitting to accommodate the wrist pin connection to the flywheel crank arm, but just has a slotted end to surround the crank arm. The power piston cylinder is ~.625" dia. and 1.3" length with a domed closure end. There are now no witness marks of ejector pins on the web surfaces between the cylinders, and no notching into the cylindrical boss of the displacer rod bushing, strongly suggesting the use of a stripper plate in place of the ejector pins on this visible surface during an injection molding process.
Typed out again, but there is still more that I'll get back to soon!
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A BRIEF HISTORY OF THE SOLAR #1, AND THE COMPANIES THAT MADE IT
Just been doing some comparative studying of a couple of my different versions of the rather common Solar #1 Stirling Engine, as produced since the late 1970's by Thermal Energy Engines of Phoenix Arizona, (TEEPA), Solar Engines of Phoenix Arizona (SEPA) until the mid-1990's and since then it is now produced by PM Research of Wellsville New York (PMR). There are strong possibilities, verging on certainty, that this basic Stirling Engine, in a slightly different form, was originally designed, produced and marketed, starting in the mid-1950's by Davies Charlton Ltd on the Isle of Man in the United Kingdom, a noted maker of petrol powered model aeroplane engines.
Due to another Thread on this Board, rather casually started by member Jasper, that has seemingly taken on a life of its own, suggesting disconnected details and speculations, while attempting to delve into the details and history of this rather interesting, typically inexpensive and otherwise generally excellent running little engine, a number of possible origins, people and companies associated with it through time have been identified and discussed, if not fully understood as to their place in the history of the design.
That thread can be seen here:
https://www.officeofsteamforum.com/general-discussion/stumbled-upon-a-vintage-solar-1/
Much like the ubiquitous VW Beetle, this little Stirling Engine has actually changed but little through its production by at least three and likely four separate entities, through a span of at least something over thirty years, and likely more than twice that time. But changes there have been, and so to define those changes, and thus help in identifying the variants currently known to exist, it seems opportune to set down for reference the details that can be known.
This thread should also be good to provide details of the individuals and companies that have been associated with the production of this Stirling Engine through the years, as information is gleaned from various sources, to help define the overall history of what has been an ongoing mystery rife with speculation and uncertainty.
I'll start with a thumbnail of the Solar #1's possible production history:
1.) Davies Charlton Ltd (D-C Ltd) .... Isle of Man UK, from 1956? to mid-1960's?, or perhaps a bit later?
Possibly (probably) designed and produced the first iteration of this Stirling Engine, which was simply called by Davies Charlton, the Hot Air Engine, and while the basic layout was nearly identical to all later version, right down to the Red/Green/Bare Metal color scheme always used, there was a major difference in the burner style used, back then it being a separate, large flat rectangular tank with a single wick appropriately located on top, and the Quonset hut/mailbox shaped housing for it, which required a large rectangular mount hole in the back part of the base. Hefin Davies, Alan Allbon and Arthur Firth appear to have been the principles in the company during the early part of this time frame, and so could be responsible for the original design and development of their Stirling Cycle Hot Air Engine.
2.) Thermal Energy Engines of Phoenix Arizona (TEEPA) .... from 1977? to 1977?
Engines with this marking on the underside of the base seem to be the first iteration of this engine to exhibit a modified base to accommodate the integral round burner and cylindrical vertical chimney housing, but otherwise appears little changed in overall appearance to the prior DC Ltd production. If this is in fact (almost certainly) the off-spring American made version, of the former UK product. Interestingly, the names in the literature seemingly first associated with this product are Clyde & John Griffin (Brothers? or Father/Son?) so perhaps they are the ones who worked out the licensing/purchase from DC Ltd to be able to produce such a close copy, if that is what happened. Quite possibly (again almost certainly) tooling was also acquired to produce the parts. It should be noted that the earliest advertisements thus far found in Popular Science (March 1978) magazine, show the rectangular hole in the back of the base for the DC Ltd style burner, but are actually referenced to the next company name (SEPA) associated with these engines ... so there may be some question as to whether TEEPA ever actually marketed any engines, even though it appears there is good evidence that at least some 6,000+ bases were produced with that name molded in underneath, before being machined out of the mold and replaced with the Solar Engines name. It was also somewhere in this time-frame that the engine went from being referred to as the "Hot Air Engine" (aka: DC Ltd), to being marketed as the "Original", and eventually "Solar 1", likely as the other heat engine offerings started to make their marketing appearance.
Though nothing substantive concerning the Griffins has as yet turned up, it may be that they were engineers and or machinists with the technical know how and ability to upgrade and modify existing tooling, or build new tooling from scratch, as well as design the entire line of subsequent offerings produced under the Solar Engines banner. However it is also possible that much of the initial redesign work on the Solar 1, as well as the designs for the subsequent line of engines, could be attributed, at least in part to Andy Ross, who clearly came into association with the engine at an early stage, and besides authoring the book that generally accompanied the Solar 1 engine, was an accomplished Stirling Cycle Engine designer and experimenter in his own right, making numerous significant contributions to the field!
3.) Solar Engines of Phoenix Arizona (SEPA) .... 1977 to 1995?
This is perhaps the most famous name associated with the Solar #1 Stirling Engine, and it is under this company's banner that the full range of more than a dozen heat engines were produced carrying the Solar Engines brand name. The Griffin's hinted at more models to come in some of the earliest ads, that still had them listed as principles in the company, though by about 1980 or even earlier, they seem to have disappeared from the scene, and the whole show seems to have been under the direction, if not actual production of Ed and Jeanette Morgan. The Morgans and their JEMCO (Jeanette & Ed Morgan Company?) Imports enterprise, may well have bought out the Griffins, or possibly the Griffins were just in as operations personnel under the Morgans all along? Once the Solar Engines logo started appearing under the engine's base, other minor changes to the engines are noted as well, such as no longer having the inboard tab for holding the chimney in place drilled and tapped for a thumbscrew, and having a small vent / pry slot, for the alcohol reservoir fuel cell cover, notched into the back edge of the base. Sometime in the early 80's the practice of hand stamping consecutive serial numbers was abandoned, but not until the count was well up into five digits, with the suggestion that it might have continued into the 20,000 range at least. Solar Engines of Phoenix Arizona actually developed and produced an impressively wide array of heat engines, many being recognized as classics and widely produced, while others were made in very limited numbers and were hardly ever advertised, so remain as extreme rarities to this day.
4.) PM Research (PMR) .... Wellsville, New York, 1995 to Present
With little change noted, other than the company name molded in underneath the base, the Solar #1 is still being produced today, essentially unchanged from SEPA production. PMR has continued production of many if not most of the SEoPA line, and certainly has continued producing all of the more common engines. The prime operatives for PMR at the time of the SEoPA purchase, appear to have been Gary Bastian and Paul Vossler. There is some suggestion that SEPA and PMR were in some level of association prior to the outright purchase of SEPA by PMR.
Note: this is just a start, and hopefully this thread can be somehow preserved, added to and be refined as information and artifacts come to the surface to flesh out this rather interesting and obviously dynamic story of a wonderful line of heat engines that all started with the humble, ubiquitous and rather excellent little Solar #1, or rather the Davies Charlton Hot Air Engine, as that actually seems the true start.
Needless to say all additions, corrections and observations are welcome here, and I do plan to come back thru with more details that I already have to hand (but am too tired of typing just now to add), along with adding pictures, as I get around to finding, taking or "stealing" them as will best suit the reference.