vintage astron alpha fin pattern

There are two major points of dissemination here that needs to be tracked objectively as possible with some deductive reasoning helping in lack of any other facts available:
1) source material with dimensions published, how is this weighed in terms of authenticity?
2) foundational basis for support of the subject information--the validity of the data- or simply, why should we trust it.

Lets start with:
1. Source material: TR-11
Of course, employees and contracted sourcing come in and out of Estes, of any company all the time, but when they stand by it with their name on the product or intellectual property right, that is of considerable (and legal) standing. It could not have been approved by Estes without their quality assurance of its content. When one writes 'Design of the Alpha' and describes the numbers used for calculation of its aerodynamics , it really doesn't get much plainer language than what you read there on 'pg 42'. Estes approved it, and that is substantial evidence to support the design.

2. Validity
There has to be numbers to go to production was the point for the whole balsa issue:
Sure one can make a model in a night, as Mike and Bill have cited in their interviews, but you have to then rationalize the numbers, as the designers themselves also have cited, with maybe the aide of drawing, so that you can have a bill of materials. A bill of material is line item list of quantities required for a single unit to be made and then cost projections are made according to resources needed to produced it. Those designers were in charge of calculating what will be needed to build the model, with no more than what it is needed to maximize economy of the unit cost (maximize profit). It was likely that there was drawing with dimensions for these calculations and then go to production of additional aides for the would-be builder, and therefore a pattern was made for this purpose as well as instructions. Patterns are derived from drawings through a production line logic. Design Development is a different contract phase that comes before Production Development. The patterns and instructions are usually made after the DD, when it can be produced rather quickly based on known dimensions from DD phase.
It is likely, and I think proven, that the dimensions come from Estes in house R&D of which TR-11 directly comes from as stated in the booklet.
This is about as certain as one can reasonably get without more facts.

To summarize, sure when can speculate on a lot of things. As you know, none none of the designers were trained as engineers. Estes being business savvy could only afford non-professionals, and to get the job done, likely trained them in-house. How much they deviated from the standard model is not really known to us, but only a little through them anecdotally through less than scholarly interviews. In short, You cannot substantiate intent. It is not factual evidence.We can only make inferences from direct observations and not second degree suppositions based on conjecture stemming from desires, imaginings of what the intent might have been.

As for this being perceived as a never ending topic, this is just standard. Professional researchers spend entire careers on one subject. As for the Alpha Fin Plan, hopefully more stuff comes to light to change the status quo, but that has to be evidential. Such as it is, now I believe this is the only reasonable conclusion one can make.

I hope this helps.

*sigh*

You write this as if Estes Industries in 1966 was some sort of government contractor, rather than a family business. And don't lecture me on the design process or bills of materials or contracts or any of that - I've been an engineer at Boeing for 36 years as of this past Thursday, on both commercial and military programs. Been there, done that.

As I noted before, the bill of materials for this model includes a 3 inch by 9 inch by 3/32 inch thick sheet of balsa stock, from which the builder was to cut the fins out, using, preferably, the supplied printed-on-heavy paper pattern using the process already discussed. And it was obvious (and still is, if you actually look) - by inspection - that one can produce the required three fins from that stock with MUCH excess material. No calculations required, no dimensions required. Just put one sheet of BFS-30 on the bill of materials and include it in the kit price calculations. Done with far less trouble and likely less cost than having just the right sized piece of balsa for that model specifically on hand, stored, inventoried, pulled correctly when the kits are bagged, etc, etc, etc. Many considerations of serial production, especially at high rates, are VERY different than those of one-off projects like most buildings.

In 1970, when that report appeared, Estes Industries was owned by the Damon. There is no reason to believe they had a QA department for things like that TR then either. Certainly someone went through the report to make sure it didn't have any blatant factual errors. But here is no reason to believe anyone verified those dimensions beyond "they're close enough" Again, they're beside the point of the paper. The dimensions you see as definitive are just measurements from built models. They define nothing beyond the numbers used in the drag buildup calculations that appear in TR-11.

TR-11 is not source material with respect to the design of the K-25 Alpha. It is derivative material and specifies nothing. It does describe how do to a drag buildup. It does use an as-built Alpha as an example of how to do the calculations, and it does report on test flight results for several variants and compare the theoretical drag affect on altitude with the measured altitudes. Using as-built dimensions, rather than any specifications removes that variable from the comparison!

I guess we'll just have to agree to disagree on this. Models built using the dimensions in TR-11 or using either the catalog handbook pattern or SP-25 will be indistinguishable in real-world performance (whether the fins are rounded, airfoiled or not, and whether they are on straight will be much bigger influences). And it would likely take more after-the-fact measuring to tell a model built one way from one built another way if they were set on the table next to each other unless, perhaps, they were put fin tip to fin tip.

Well all this talk about "old" Alpha's.... how about a pic!


These were found in my parents attic in 1999! Couldn't believe it. All wrapped and boxed up, perfect condition.

They were all built between 1966 -1967 when I was in 8 grade - freshman high school. Many Motors were 99 cents and came in the blue tube.

Any one figure out how old these motors are by chance?

Nozzle & for end shot are of booster motor. Actually looking at these amazes me how good I was at building, considering I was a kid. Fin are all aligned pretty darn near perfect, fillets spot on.
The Arcus & V-2 were feathered and air foiled.

You don't know anything about DAMON.
And you dont have to, is the point.
What you are suggesting has nothing to the corporate ownership, as there is no foundational underpinnings in the form of facts to support it.

The nice thing about data, is that you can have repeatable events and results. Quality control. Yes I think Estes had quality control in the form best handled by he company at the time.
It doesn't take much to make a drawing and put in a flat file with all the associated record docs for purposes of auditing,future designs in their R&D Department, and tracking when required for tracking of work done for each employee. Even the smallest one man offices have paper trails and a file cabinet. I have no overarching belief in a unfounded story ( lack of facts) to refute evidence such as TR-11. You have to come to a reasonable conclusion given the evidence, until proven otherwise with new evidence that can contradict it, likely in the form of other alternate dimensions.

And in that flat file is probably a hand-drawn (by Bill Simon) fin pattern for the original Alpha. Any data subsequent to that would have been derived from that - directly or indirectly - including any published numbers by anyone anywhere. How much the Damon corporation cared or didn't is really irrelevant - you're right about that.

You just can't seem to accept that sometimes parts of flying machines are defined graphically, can you? Many of them are, in fact. Nowadays it's 3D solid models on computers. In the time frame we're talking about it's lines on paper or vellum or mylar - whether we're talking about model rockets or airliners. Some parts (for example hydraulic tubes) are even defined by sample parts (and the bill of material for that assembly includes how much straight tubing stock you need to bend the shape of the actual part from along with markings, standards used on the ends and so forth). But the sample's shape IS the definition.

No, we don't do it that way any more, but in 1967 (or 1970 for that matter) that was how it was done. And spares even today go back to those samples.

Enough. I could have built an Alpha in the time I've spent on this. Time to do that instead of typing anymore.....


Oh - Jim - those Estes motors are all pre-SI marked motors (average thrust in pounds rather than Newtons). They last appeared in the 1967 catalog marked that way....so at least an endpoint for how old they are. No idea about the Centuri boosters.

Raygun said:

I assume it as data that is specified to describe the design of the Alpha (as per the title of fig. 76). Why would you disseminate anything but the data published? Your 'expectation' is speculative as you know, and yet you build upon it with more. Its lacks basis just like my earlier example, it cannot be supported by facts that we know. We only know dimensions of the fin plan, and that they were published by Estes.

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TR-11 was written by Dr. Gregorek. He did not work for Estes. He probably measured a set of fins and wrote the dimensions down. While it is possible an editor at Estes changed any figures before the publication was typeset, it is not likely, and we'll never know anyway. Of course, the measurements in the report match mine, and they do not match the pattern in the yellow pages, so I'm pleased, but I would not take the report measurements as definitive, just supportive.

This is an awesome thread!

RoyAtl said:

TR-11 was written by Dr. Gregorek. He did not work for Estes. He probably measured a set of fins and wrote the dimensions down. While it is possible an editor at Estes changed any figures before the publication was typeset, it is not likely, and we'll never know anyway. Of course, the measurements in the report match mine, and they do not match the pattern in the yellow pages, so I'm pleased, but I would not take the report measurements as definitive, just supportive.

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To summarily point out, its not so much the business relationship of the author to Estes that is of relevance here. Its the fact that Estes approved to have their name associated with the content and the call out in the title of 'The Astron Alpha' as the the design of the model rocket design in question. That's what make it compelling: that they were okay with calling a trademarked ( informally and conservatively speaking) Alpha, 'The Astron Alpha' in the title of their figure describing it. Speculative though it may be, because we really don't know, it's not a difficult conclusion to make that so-and-so said "sure come to our R&D department and talk to x and he'll give you what you need.l.." or, "He'll send some material over to you on a basic model that we like for you to use...", based on dimensioned drawings from their R&D files. Hence we see it published, ultimately, with as final source by R&D department as stated in TR-11 (pg.3). Alpha came out in 67', report published by Estes R&D 70'. R&D department as possibly likely source of basic reference information? Well let me just state that 'Supportive' is a word, in my opinion, that is at best understating the matter, because they published it. That's why I view it as definitive. For me, that is a known quantity that has more relevance far beyond my, yours,or really anyone's speculation. Speculation on this matter is irrelevant and moot. The facts present themselves plainly and without reservation.

:grin::grin::grin::grin::grin:Maybe this will kill this thread: Arguing about Estes Alpha fin pattern may cause erectile disfunction.

Ok. The thread got interesting. Good points argued to death. Glad we have a place to do such.

But the point has been lost and gotten confusing. Which fin goes to what kit from what year? I'm wanting to build the entire fleet. Including every fin and nosecone variation.

Kruegon said:

Ok. The thread got interesting. Good points argued to death. Glad we have a place to do such.

But the point has been lost and gotten confusing. Which fin goes to what kit from what year? I'm wanting to build the entire fleet. Including every fin and nosecone variation.

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There is only one fin pattern for the basic Alpha kit. There might be very slight discrepancies from the original patterns to the die mashed and laser cut versions, but they all generally agree. They even agree with the planform of the Alpha III, and of the Super Alpha (the Maxi-Alphas have a distinctly different pattern, probably for a reason). The pattern that was printed in the 1969-1971 center catalog insert ("Model Rocketry Technical Manual") is the outlier, having significantly less span, and larger tip chord, than the kit. It *is* labeled as an Alpha in those instructions, so it has to be allowed as an Alpha, but it is not *THE* Alpha, and certainly I've seen many Alphas in my 47 years flying model rockets and not once have I seen an Alpha built with that fin pattern. I've seen plenty of Alphas with their fins attached by their trailing edges, but none with the 'catalog' fin pattern. In my humble opinion, my explanation for the catalog fin pattern -- that it was distorted to fit the page -- is the most likely one.

I used the pdf of the k25 fin pattern to print a template for my 1970 alpha. do the fins match exactly, dunno, but they are close enough for me. it flies great on A8-3s.
Rex

RoyAtl said:

I've seen many Alphas in my 47 years flying model rockets and not once have I seen an Alpha built with that fin pattern. I've seen plenty of Alphas with their fins attached by their trailing edges, but none with the 'catalog' fin pattern. In my humble opinion, my explanation for the catalog fin pattern -- that it was distorted to fit the page -- is the most likely one.

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That could be. That said, the laser-cut fins you could get from Semroc for the Alpha (the K-25 fins) were that shape. I have one Alpha built with one of those fin sets and two or three more sets of the fins on hand..... So if you want to see a picture of an Alpha with those fins I can post a picture.

Actually, it's the second from the left here: https://www.oldrocketforum.com/attachment.php?attachmentid=19145

The others are, from left to right: an Alpha built from a fairly recent bulk kit - laser cut fins, blow-molded nose cone. The Alpha II clone with the Semroc K-25 laser cut fins. A recent Alpha III (from a launch set in 2010) with its body tube replaced by a length of Semroc/Centuri ST-9 after a mishap, an Alpha III from a US-made bulk pack (date not known) and an Alpha IV.

dlazarus6660 said:

Anyone ever build one of these and stuff a 'D' motor in and fly it?:y:

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It's funny that I found your post, as I was reviewing this Thread before starting my next build, a MD Alpha! 24mm fits the Tube, so just like my 24mm Crossfire DX, the Astron Alpha DX will become reality.

Alright, Raygun. I spoke with the designer of the Alpha, Bill Simon, this afternoon at NARCON. I had with me an SP-25 scan, a printout of TR-11 and an original 1970 catalog with the Model Rocketry Technical Manual pages within it (beginning on 57). I described the gist of this discussion and his immediate response was that the SP-25 fin pattern is definitive. It was drawn by Gene Street making use of the handmade original cardstock fin pattern Bill used to create the fins for the Alpha prototype on his kitchen table.

Bill also averred as how Mr. Street may have altered it slightly in creating that page in the catalog (page 58 in that 1970 catalog). He basically didn't recognize the drawing in TR-11 at all.

As noted before, TR-11 was written by Jerry Gregorek (who was an active competitor in model rocketry, and working in academia at the time). He was not an Estes employee and based on Bill Simon's reaction to seeing the report today, he was not asked to review it before publication. He WAS still working at Estes Industries R&D department at that time.

So you can continue to cling to your chain of circumstances for claiming that those published dimensions are definitive if you like. But I have heard today, straight from the designer's mouth, that the SP-25 fin pattern is definitive. There was no "in house R&D department check" nor were those dimensions, per se, furnished to Dr. Gregorek for TR-11.

I stand by my conclusion that Dr. Gregorek simply measured built examples, recorded those dimensions in the report and used them as illustrative for the purpose of the drag calculations that are the point of that report. The define nothing beyond the values used for calculating the drag as shown in the report.

As I have noted before, there are many precedents for parts being defined by master patterns or graphical representations with no dimensions required. Mr. Simon today confirmed the original fin shape of the Astron Alpha rocket was one of these. And once again - it is obvious by inspection that more than three of these fins (the required number) can be easily cut from a standard piece of BFS-30 fin stock, and the bill of material for the kit simply includes one such piece of fin stock. No dimensions required for the fins themselves to do this.

thank you for posing the question and reporting the answer.
Rex

Bravo!

Thanks Bernard,

I can finally sleep tonight!

This was an interesting thread and I think it's fairly rare for a discussion to go on this long without it being acrimonious.

Nice that you were able to speak to the designer and get this question sorted out. It's about as definitive as you can get.

Makes me want to go build another Alpha.

foamy said:

Makes me want to go build another Alpha.

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Yeah, me, too.

I'm kicking myself that I didn't take one of the Alphas I already have (probably the Alpha II clone) with me to the MoF on Saturday along with all that documentation so that I could've gotten Bill's signature on the model. I spent the time I was up there Sunday down in the basement doing two Make-It Take-It/Intro to Model Rocketry sessions back to back and didn't even know if he (or the Estes' or the Piester's) were even about on Sunday.

hcmbanjo said:

Thanks Bernard,

I can finally sleep tonight!

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If this has been preventing you from sleeping you're worse off than me!

BEC said:

snip... I spent the time I was up there Sunday down in the basement doing two Make-It Take-It/Intro to Model Rocketry sessions back to back and didn't even know if he (or the Estes' or the Piester's) were even about on Sunday.

Click to expand...

Well heck, you were doing something good for the hobby. A tip 'o the hat to you.

Missing an opportunity to have Mr. Simon autograph an Alpha sounds like something I'd do (Cap'n Scattered, here). I feel for ya.

BEC said:

Alright, Raygun. I spoke with the designer of the Alpha, Bill Simon, this afternoon at NARCON. I had with me an SP-25 scan, a printout of TR-11 and an original 1970 catalog with the Model Rocketry Technical Manual pages within it (beginning on 57). I described the gist of this discussion and his immediate response was that the SP-25 fin pattern is definitive. It was drawn by Gene Street making use of the handmade original cardstock fin pattern Bill used to create the fins for the Alpha prototype on his kitchen table.

Bill also averred as how Mr. Street may have altered it slightly in creating that page in the catalog (page 58 in that 1970 catalog). He basically didn't recognize the drawing in TR-11 at all.

As noted before, TR-11 was written by Jerry Gregorek (who was an active competitor in model rocketry, and working in academia at the time). He was not an Estes employee and based on Bill Simon's reaction to seeing the report today, he was not asked to review it before publication. He WAS still working at Estes Industries R&D department at that time.

So you can continue to cling to your chain of circumstances for claiming that those published dimensions are definitive if you like. But I have heard today, straight from the designer's mouth, that the SP-25 fin pattern is definitive. There was no "in house R&D department check" nor were those dimensions, per se, furnished to Dr. Gregorek for TR-11.

I stand by my conclusion that Dr. Gregorek simply measured built examples, recorded those dimensions in the report and used them as illustrative for the purpose of the drag calculations that are the point of that report. The define nothing beyond the values used for calculating the drag as shown in the report.

As I have noted before, there are many precedents for parts being defined by master patterns or graphical representations with no dimensions required. Mr. Simon today confirmed the original fin shape of the Astron Alpha rocket was one of these. And once again - it is obvious by inspection that more than three of these fins (the required number) can be easily cut from a standard piece of BFS-30 fin stock, and the bill of material for the kit simply includes one such piece of fin stock. No dimensions required for the fins themselves to do this.

Click to expand...

Okey Doke!
That sounds good, at least that is better than what we had before, so maybe SP-25 with its crooked lines and all, are the original form of the production design. I just wasn't convinced that is the case with info floating around at or near the same time after kit release. Jim Zalweski still does not have it posted on his site yet, but hoping that will be there for everyone eventually.It should probably get in the Rocket Shoppe too.

Finished my 24mm FG Clothed version yesterday.
Thanks this Thread!!!





Artists Concept:



Actual Launch:

View attachment 261162

BEC said:

Alright, Raygun. I spoke with the designer of the Alpha, Bill Simon, this afternoon at NARCON. I had with me an SP-25 scan, a printout of TR-11 and an original 1970 catalog with the Model Rocketry Technical Manual pages within it (beginning on 57). I described the gist of this discussion and his immediate response was that the SP-25 fin pattern is definitive. It was drawn by Gene Street making use of the handmade original cardstock fin pattern Bill used to create the fins for the Alpha prototype on his kitchen table.

Bill also averred as how Mr. Street may have altered it slightly in creating that page in the catalog (page 58 in that 1970 catalog). He basically didn't recognize the drawing in TR-11 at all.

As noted before, TR-11 was written by Jerry Gregorek (who was an active competitor in model rocketry, and working in academia at the time). He was not an Estes employee and based on Bill Simon's reaction to seeing the report today, he was not asked to review it before publication. He WAS still working at Estes Industries R&D department at that time.

So you can continue to cling to your chain of circumstances for claiming that those published dimensions are definitive if you like. But I have heard today, straight from the designer's mouth, that the SP-25 fin pattern is definitive. There was no "in house R&D department check" nor were those dimensions, per se, furnished to Dr. Gregorek for TR-11.

I stand by my conclusion that Dr. Gregorek simply measured built examples, recorded those dimensions in the report and used them as illustrative for the purpose of the drag calculations that are the point of that report. The define nothing beyond the values used for calculating the drag as shown in the report.

As I have noted before, there are many precedents for parts being defined by master patterns or graphical representations with no dimensions required. Mr. Simon today confirmed the original fin shape of the Astron Alpha rocket was one of these. And once again - it is obvious by inspection that more than three of these fins (the required number) can be easily cut from a standard piece of BFS-30 fin stock, and the bill of material for the kit simply includes one such piece of fin stock. No dimensions required for the fins themselves to do this.

Click to expand...

Okay, I'm such a dork for having read this thread, but at least it paid off in the end.

SolarYellow said:

Okay, I'm such a dork for having read this thread, but at least it paid off in the end.

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Thanks, I think, for popping this thread back up.

Just to follow on @TopRamen’s post just above, now one doesn’t have to fiberglass and otherwise reinforce the structure of an Alpha to have the big white flame experience. Here is the first Alpha my wife built, painted in the colors of our college alma mater, going up on a Q-Jet C18-6W on Sunday at the Tri-Cities Rocketeers‘ Sod Blaster IV event (screen grab of slow motion iPhone video frame).

It went to 1309 feet and reached a maximum speed of 425 mph per the PerfectFlite FireFly aboard. It is a clone, made of mostly Semroc parts, of the Alpha with a balsa nose cone, hand cut fins per SP-25, and the two-ring motor mount. As such it’s rather lighter than current kit-built Alphas. No extra reinforcements needed for zero to 425 mph in 0.6 seconds.

When it takes off like that even the high power guys are impressed. She flew it again on a C18-8W on Monday with similar fun results.