Estes Ranger and Big Bertha

[JAL3]

Would I be correct to assert that the Ranger is just a Bertha with a cluster mount?

[tbzep]

Would I be correct to assert that the Ranger is just a Bertha with a cluster mount?

Just the opposite. The Ranger came first, when Estes only made A and B motors. Vern then designed the single mount Bertha. Also, the Ranger has a payload section and the Bertha doesn't.

[JAL3]

From what I can tell in the catalog pics, the size was the same and the fin profiles look the same. Could I say that they are the same outside but with different innards?

[JAL3]

Also, the 1986 version of the Ranger (1955) looks similar but different from the original. It is a bit shorter and has a single motor mount. Would you still consider them part of the same "family"?

[Ltvscout]

Also, the 1986 version of the Ranger (1955) looks similar but different from the original. It is a bit shorter and has a single motor mount. Would you still consider them part of the same "family"?
This Ranger is a completely different kit. It used the nosecone made for the sport-scale Exocet if I'm not mistaken. Estes often reuses kit names.

[tbzep]

From what I can tell in the catalog pics, the size was the same and the fin profiles look the same. Could I say that they are the same outside but with different innards?
IIRC, over the years the fin pattern has changed slightly along the Ranger/Bertha line, but not enough to notice without putting them together.

The 1955 Ranger had a smaller BT-55 body tube, different shaped fins, and a different nose cone along with the single 24mm mount. I personally wouldn't include it in the family, but others might.

[mwtoelle]

Another note: the Big Bertha first appeared as one of Estes' free plans (EIRP #13).
Link: http://www.spacemodeling.org/JimZ/eirp_13.htm

[JAL3]

This Ranger is a completely different kit. It used the nosecone made for the sport-scale Exocet if I'm not mistaken. Estes often reuses kit names.

I'm glad when somebody knowledgable confirms my gut feel, except that it tends to lead me to think I am much more competent than I really am...

Thanks.

[JAL3]

IIRC, over the years the fin pattern has changed slightly along the Ranger/Bertha line, but not enough to notice without putting them together.

The 1955 Ranger had a smaller BT-55 body tube, different shaped fins, and a different nose cone along with the single 24mm mount. I personally wouldn't include it in the family, but others might.


Let me see if I can acurately summarize your considered opinion.

1. The original Ranger can be said to be part of the same family as the Big Bertha

2. The 1955 Ranger is at best, a distant relation and the family would do well not to claim it


If by family I am including Big Bertha, Super Big Bertha, Mini Bertha and Baby Bertha, The original Ranger would probably belong in the group but the newer one probably not.


Does that make sense?

[JAL3]

Another note: the Big Bertha first appeared as one of Estes' free plans (EIRP #13).
Link: http://www.spacemodeling.org/JimZ/eirp_13.htm


Now that tidbit is VERY appreciated.

I would call it the farthest back ancestor.

[Doug Sams]

If by family I am including Big Bertha, Super Big Bertha, Mini Bertha and Baby Bertha, The original Ranger would probably belong in the group but the newer one probably not.

Does that make sense?Yes. I think that sums it up very nicely.

Doug

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[JAL3]

Thank you so much.

[BEC]

That original Big Bertha plan appeared in the April/May 1963 issue of Model Rocket News (which is also on JimZ - all four pages of it).

In that issue on another page it mentions "all eight" Estes kits, including the Ranger. So I think that confirms that the Ranger came first - but the gap was not very big.

It's interesting that that MRN plan of the Big Bertha doesn't have the partial stuffer tube we've seen in later versions - just a 2060 motor mount and lots of empty space for a parachute.

I'd say that - following the family metaphor - the K-6 Ranger is the father of all the Bertha variations. One of these days I'm going to have to actually build a Big Bertha. I have cloned the Ranger, and I've done several Baby Berthas. I also have evidence in my old rocketry stuff from the early '70s that I'd build a Mini Bertha...but I don't have it or remember building it. I do have a Big Bertha "work alike" in my much flown Semroc Vega....

[gpoehlein]

I'm in the same boat - I've semi-cloned the Ranger from a Bertha (used the plastic nose cone and made a bulkhead from a coupler and two disks of foamcore), but I haven't actually built a Bertha yet. Gonna have to get around to that one of these days! :rolleyes:

[JAL3]

Let's take this a bit further.

Would the Semroc SLS Brighton be considered a member of the extended family?

If so, what others would you add?

By member of the family, I mean that the rocket is a clone or its design is a fairly straight forward derivative. By the "logic" I am using, the Baby Bertha is a member because:

1. It is a truncated Bertha
2. Estes obiously intended it hence the name.

I would not call the Big Betty a member. I would consider it a Quest "analog", it holds the same place in the Quest Stable.

[CPMcGraw]

Let me see if I can acurately summarize your considered opinion.

1. The original Ranger can be said to be part of the same family as the Big Bertha

2. The 1955 Ranger is at best, a distant relation and the family would do well not to claim it


If by family I am including Big Bertha, Super Big Bertha, Mini Bertha and Baby Bertha, The original Ranger would probably belong in the group but the newer one probably not.


Does that make sense?

Add to this the original Apogee and Apogee II kits. Notice the sustainer stages. They could be considered the 'grandparents' to the Mini Bertha.

[JAL3]

Add to this the original Apogee and Apogee II kits. Notice the sustainer stages. They could be considered the 'grandparents' to the Mini Bertha.


I am not familiar with them to know but that begs the question of when the "family" branches off to create a new family.

I don't have an answer except for gut feel and YORF consensus.

[tbzep]

I am not familiar with them to know but that begs the question of when the "family" branches off to create a new family.

I don't have an answer except for gut feel and YORF consensus.
Think of them as a Mini Bertha with clear payload section and a booster stage. ;)

Click here for a quick look at the Apogee II. (http://www.ninfinger.org/rockets/catalogs/estes67/67est24.html)


.

[CPMcGraw]

I am not familiar with them to know but that begs the question of when the "family" branches off to create a new family.

I don't have an answer except for gut feel and YORF consensus.

Here they are, side-by-side, in glorious black & white: LINKY to Ninfinger (http://www.ninfinger.org/rockets/catalogs/estes63/63est8.html)

[JAL3]

Here they are, side-by-side, in glorious black & white: LINKY to Ninfinger (http://www.ninfinger.org/rockets/catalogs/estes63/63est8.html)


I see the family resemblance.

Could it then be said that a large part of the resemblance is due to the early stages of rocketry and there not being that many starting points for a young company?

[BEC]

Think of them as a Mini Bertha with clear payload section and a booster stage. ;)

And an 18 x 70mm motor mount instead of 13 x 45mm motor mount.....

[tbzep]

And an 18 x 70mm motor mount instead of 13 x 45mm motor mount.....
Or the original Apogee with the 18mm shorty motors. ;)

[JAL3]

I'm trying to learn this stuff but it seems you guys absorbed it and memorized it in your formative years.

I used to stare at my catalogs at night but the text did not seem to register in the same way as with y'all!

[JAL3]

Another Bertha question:

The 1986 catalog changes the model number from 1223 to 1948. The rocket is also listed as "updated". I see that it still had 18mm mount.

Did anything change except for the livery/decal?

[BEC]

Or the original Apogee with the 18mm shorty motors. ;)

I didn't know that. The only catalog posted on Ninfinger that contains the original Apogee contains no motor listings, nor do the catalog pages list recommended motors for the kits. Innnterrrrrrrrrrresting.............

This was slightly before my first rocketry period. The first catalog that I really remember is the 1967 catalog. I would've been 12 that year.

[Mark II]

Now that tidbit is VERY appreciated.

I would call it the farthest back ancestor.That was Bertha before she got hitched to Ranger. The results of that subsequent union were Minnie, Super and the Baby. ;)

[Mark II]

Add to this the original Apogee and Apogee II kits. Notice the sustainer stages. They could be considered the 'grandparents' to the Mini Bertha.I would want to get blood tests to determine that. I don't see any resemblance at all. There is a distinct resemblance to the Taser Twin, but not to any Berthas that I can see.

The later Ranger kit was simply someone with the same name. I don't think that every John Lee in the US is your relative, right? :chuckle:

[Mark II]

Let's take this a bit further.

Would the Semroc SLS Brighton be considered a member of the extended family?Bertha and the Brighton are from different parts of the country. They look very much alike but do not share the same lineage. Under the skin, they are very different.

Vega and Betty are even more distant. They are related to Bertha like a zebra is related to a horse.

Sure, on some far removed level they are all related...just like we are all related to Adam. Or Attila the Hun. ;) (My mother used to say that.)

[Mark II]

I'm trying to learn this stuff but it seems you guys absorbed it and memorized it in your formative years.

I used to stare at my catalogs at night but the text did not seem to register in the same way as with y'all!I flew rockets in the 1960s, but I didn't learn most of the stuff that we are talking about here until this century.

[Mark II]

I see the family resemblance.

Could it then be said that a large part of the resemblance is due to the early stages of rocketry and there not being that many starting points for a young company?Yup, they look alike. Just as I look like anyone else who was born in Michigan. :p

[Carl@Semroc]

The Astron Ranger was definately the first in the family. The Ranger is also the first to use the BT-60. If you follow the progression on the earliest kits, K-1 (Scout) used the BT-30 that was originally hand-rolled. The next two (Mark and Space Plane) also used the BT-30. These were from New England Paper Tube and were convolute wound. The next (Streak) used a spiral mylar tube (BT-10) from Euclid. The K-5 (Astron Apogee) used the same mylar tube for the payload section and added the BT-20 in glassine coated spiral kraft for the first use in a kit. The Ranger came next and since it used three BT-20 tubes, it was only natural to name the large tube the BT-60 since 3 times 20 is 60.

Filling out the other sizes were the BT-40 which was slightly larger than the BT-30, also convolute, and was left overs from the MMI buyout. I don't believe any Estes kits ever used the BT-40, although a few plans called for it. Legend has it the the BT-50 was added as the largest size tube that could have a balsa nose cone cut from standard 1" x 1" square stock withough having flat spots. The Centuri ST-10 had to start with 1.25" by 1.25" stock to avoid flat spots. That almost doubled the balsa cost. The Cobra was the first to use the BT-50, followed by the Farsides. Since the BT-50 was already used, it also served as the engine mount for the new D engines later.

Vern built the first Big Bertha from Ranger parts for a quick demo. He left the 18" tube instead of breaking it into the 7" and 11" sections that were used in the Ranger. The fins were cut from the same pattern as the Ranger, but like many fins cut from patterns were slightly different. He still has the original Big Bertha and still flies it at NARAM's. It still has the black plastic chute. He still ues a layer of tape around the base of the engine and engine tube since it was built before engine hooks were used in kits. Over the years the slotted tube shock mount was replaced with the Alpha tri-fold. The nose cone is probably one of the earliest that still exists. Our copy of it is the BNC-60LV which is slightly different from other BNC-60L nose cones from the early days. The later Berthas replaced the balsa nose cone with plastic and tended to be more elliptical than ogive. The plans for the Big Bertha were published in April, 1963, but it was not released as a kit until 1965. I always thought engine sales were the reason. Why sell a rocket that uses just one engine when you already have one that looks just like it that uses three engines?

And, yes, the SLS Brighton is an upscale of the Ranger, the original Bertha, which is German for "bright." The Semroc Vega was a clone of the earliest plans for the Big Bertha which had a much more ogive nose cone. Now I realize it was drafting error and not the correct shape that was actually used. The Semroc Goliath came after the Vega and shared the same parts. For the same reason, we discontinued the Vega around 1969 to sell more engines with the Goliath.

[Doug Sams]

Why sell a rocket that uses just one s.ngine when you already have one that looks just like it that uses three engines?I've always viewed the Big Bertha as having two key features that made it popular with kids. Its size and cost. In the 1969 catalog, it was 2 bucks, versus $1.50 for the Alpha. For 50 cents more, the kids got a rocket nearly twice the size of the Alpha. And, being a 3FNC, it presented few challenges to young builders.

Basically, it was my first "large" rocket (compared to my Alphas, Sprite, Streak, Scout, Mark2, etc). While it wasn't "large" powered, it was still impressively big to me, circa age 9. And, at 2 bucks, was quite affordable.

So those are the factors I think which made it very popular.

Compared to the Ranger, no doubt the single mount reduced flying costs for kids, and, perhaps more importantly, eliminated the technical challenge of clustering.

Anyway, I always thought size and affordability are what made the Bertha so popular.

Doug

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[ghrocketman]

The Big Bertha is a VERY BORING version of the Astron Ranger; as mentioned above, it has no payload section and a single 18mm mount instead of the 3x18mm cluster engine mount.
Have several Rangers, but never a Bertha as it seems like a car with no options. YUCK.

[JAL3]

The Astron Ranger was definately the first in the family. The Ranger is also the first to use the BT-60. If you follow the progression on the earliest kits, K-1 (Scout) used the BT-30 that was originally hand-rolled. The next two (Mark and Space Plane) also used the BT-30. These were from New England Paper Tube and were convolute wound. The next (Streak) used a spiral mylar tube (BT-10) from Euclid. The K-5 (Astron Apogee) used the same mylar tube for the payload section and added the BT-20 in glassine coated spiral kraft for the first use in a kit. The Ranger came next and since it used three BT-20 tubes, it was only natural to name the large tube the BT-60 since 3 times 20 is 60.

Filling out the other sizes were the BT-40 which was slightly larger than the BT-30, also convolute, and was left overs from the MMI buyout. I don't believe any Estes kits ever used the BT-40, although a few plans called for it. Legend has it the the BT-50 was added as the largest size tube that could have a balsa nose cone cut from standard 1" x 1" square stock withough having flat spots. The Centuri ST-10 had to start with 1.25" by 1.25" stock to avoid flat spots. That almost doubled the balsa cost. The Cobra was the first to use the BT-50, followed by the Farsides. Since the BT-50 was already used, it also served as the engine mount for the new D engines later.

Vern built the first Big Bertha from Ranger parts for a quick demo. He left the 18" tube instead of breaking it into the 7" and 11" sections that were used in the Ranger. The fins were cut from the same pattern as the Ranger, but like many fins cut from patterns were slightly different. He still has the original Big Bertha and still flies it at NARAM's. It still has the black plastic chute. He still ues a layer of tape around the base of the engine and engine tube since it was built before engine hooks were used in kits. Over the years the slotted tube shock mount was replaced with the Alpha tri-fold. The nose cone is probably one of the earliest that still exists. Our copy of it is the BNC-60LV which is slightly different from other BNC-60L nose cones from the early days. The later Berthas replaced the balsa nose cone with plastic and tended to be more elliptical than ogive. The plans for the Big Bertha were published in April, 1963, but it was not released as a kit until 1965. I always thought engine sales were the reason. Why sell a rocket that uses just one engine when you already have one that looks just like it that uses three engines?

And, yes, the SLS Brighton is an upscale of the Ranger, the original Bertha, which is German for "bright." The Semroc Vega was a clone of the earliest plans for the Big Bertha which had a much more ogive nose cone. Now I realize it was drafting error and not the correct shape that was actually used. The Semroc Goliath came after the Vega and shared the same parts. For the same reason, we discontinued the Vega around 1969 to sell more engines with the Goliath.

Well that seems like the definitive voice of authority to me.

Its nice how anything related to Carl McLawhorn seems to be a good experience, whether a a response to a forum post or a white box of magic that shows up on my doorstep! :D

[stefanj]

The Big Bertha may be "boring," but it costs about 1/3rd as much to fly, is a lot easier to prep, and can be routinely flown in small fields.

[foamy]

It'd be interesting to know what Estes most popular (by sales) rocket has been over the years. The 'Bertha been produced for quite a while now.

[carbons4]

Somebody mentioned the size thing. We used to go to the schools and hobby store promotions and like you said, for the money you could get a rocket almost twice the size of a Alpha with a Bertha. Estes did their marketing homework. For somebody that is new to rocketry it's the whole ,oooh ahhh that one's big. Guess that old thing of "size matters" starts out early in life.

[ghrocketman]

You can fly the Ranger clustered in small fields with 1/2A6-2's.
Bunk on the single engine baloney.
ANYTHING BT-60 or larger with a single engine should have a minimum of a 24mm mount BY LAW.

[Doug Sams]

ANYTHING BT-60 or larger with a single engine should have a minimum of a 24mm mount BY LAW.I understand why the Bertha didn't have a 24mm mount - the motors didn't exist at the time. But I don't understand why today they don't have a version with that option. Call it Fast Bertha or Bat Outtahell Bertha or Big Bad Bertha or any one of 100 other names, but they ought to offer a Bertha variant with a 24mm mount (BT-60 Berthas, not the BT-80 Super series). It just begs for that.

For that matter, so do about half the releases over the last couple of years. Lots of BT-55 and BT-60 sized kits in there with 18mm power that, with 24mm power, wouldn't be any more loss-prone than Cherokee-D's. (And they could still be adapted down to 18mm power.)

I don't want folks overflying their fields and losing their rockets, but some of these kits are begging for power upgrades. I suppose, die hards will do that anyway. But it just seems to me that Estes (already) has lots of kits that should have be offered with 24mm power.

Doug

.

[BEC]

ANYTHING BT-60 or larger with a single engine should have a minimum of a 24mm mount BY LAW.

Interesting comment from Mr. "INDIVIDUAL FREEDOM". :rolleyes:

And, being a 3FNC, it presented few challenges to young builders.

You mean, of course, a 4FNC.....:)

[Doug Sams]

You mean, of course, a 4FNC.....:)D'oh! :o

Doug

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[Mark II]

In case anyone missed it, my description of the Ranger-Bertha family was metaphorical. The family tree wasn't intended to be authoritative.

[CPMcGraw]

In case anyone missed it, my description of the Ranger-Bertha family was metaphorical. The family tree wasn't intended to be authoritative.

Metaphorical, but useful. It shows how a single design idea can morph over time to become a "family" of rockets. It all started with a simple design "element", in this case, the fin shape, and has developed into at least three body tube diameters worth of kits.

[tbzep]

The Big Bertha is a VERY BORING version of the Astron Ranger; as mentioned above, it has no payload section and a single 18mm mount instead of the 3x18mm cluster engine mount.
Have several Rangers, but never a Bertha as it seems like a car with no options. YUCK.

Yer not doin it right! :chuckle:

A Bertha with a B6-2 or a C6-3 and a keychain cam taped to it is fun, especially with a group of 3rd graders underneath and in the frame.

A Bertha is also the perfect chad stage rocket. D12-0 to A/B/C. Nose weight isn't needed...just let it rip. I've done several D12 to C6 flights just for the heck of it.

The reason I like doing stuff with the Bertha is because it's often a fairly plain to down right ugly rocket, according to how it's finished, and I don't mind banging it up or losing it. And of course, with that mentality, I have never lost a Bertha. That's why I usually use it as my camera platform.

[Mark II]

Clusters are exciting, no doubt about that. They are even more exciting when one or more of the motors fails to ignite. :D

Clusters are more complicated to prep as well as being more expensive to launch. So there's a price to pay for all of that drama. Clusters are great; I love them. I can't launch them all the time, though.

Want to make that next Big Bertha launch more riveting? Put a D21 in it. ;)

[JAL3]

Clusters are exciting, no doubt about that. They are even more exciting when one or more of the motors fails to ignite. :D

Clusters are more complicated to prep as well as being more expensive to launch. So there's a price to pay for all of that drama. Clusters are great; I love them. I can't launch them all the time, though.

Want to make that next Big Bertha launch more riveting? Put a D21 in it. ;)

I still have an old AT 18mm E. If I ever get around to building a Bertha, I might try that.

[tbzep]

I still have an old AT 18mm E. If I ever get around to building a Bertha, I might try that.
You'd better fly it at the church youth launch so someone with young legs can retrieve it from way over yonder. ;) (even with the 12" chute)

[BEC]

Have done both the keyfob camera and the Aerotech D (though I use the D10s) in my Semroc Vega. I have some videos of D10-powered flights. Haven't tried a camera on the Ranger yet (or flown it on more than B-impulse motors).

[gpoehlein]

Actually, I LIKE watching a Bertha go on a single B6 - it has a kind of slow, majestic liftoff that you can actually see as it goes up!

Greg

[JAL3]

Actually, I LIKE watching a Bertha go on a single B6 - it has a kind of slow, majestic liftoff that you can actually see as it goes up!

Greg


THAT is one of the biggest differences between my attitude as a kid and now. Back then I shoved in the biggest motor I could find. Recommendations were not considered.

Now I would rather be able to actually see things. I loose interest quickly when I can no longer see.

Another moderating factor these days is if I have a kid from the church to shag for me. :D Then I figure I ought to use my supply of bigger motors.

[jdbectec]

I still have an old AT 18mm E. If I ever get around to building a Bertha, I might try that.

Been there, done that, AWESOME!
:D

[dannymrmissile]

The Astron Ranger was definately the first in the family. The Ranger is also the first to use the BT-60. If you follow the progression on the earliest kits, K-1 (Scout) used the BT-30 that was originally hand-rolled. The next two (Mark and Space Plane) also used the BT-30. These were from New England Paper Tube and were convolute wound. The next (Streak) used a spiral mylar tube (BT-10) from Euclid. The K-5 (Astron Apogee) used the same mylar tube for the payload section and added the BT-20 in glassine coated spiral kraft for the first use in a kit. The Ranger came next and since it used three BT-20 tubes, it was only natural to name the large tube the BT-60 since 3 times 20 is 60.

Filling out the other sizes were the BT-40 which was slightly larger than the BT-30, also convolute, and was left overs from the MMI buyout. I don't believe any Estes kits ever used the BT-40, although a few plans called for it. Legend has it the the BT-50 was added as the largest size tube that could have a balsa nose cone cut from standard 1" x 1" square stock withough having flat spots. The Centuri ST-10 had to start with 1.25" by 1.25" stock to avoid flat spots. That almost doubled the balsa cost. The Cobra was the first to use the BT-50, followed by the Farsides. Since the BT-50 was already used, it also served as the engine mount for the new D engines later.

Vern built the first Big Bertha from Ranger parts for a quick demo. He left the 18" tube instead of breaking it into the 7" and 11" sections that were used in the Ranger. The fins were cut from the same pattern as the Ranger, but like many fins cut from patterns were slightly different. He still has the original Big Bertha and still flies it at NARAM's. It still has the black plastic chute. He still ues a layer of tape around the base of the engine and engine tube since it was built before engine hooks were used in kits. Over the years the slotted tube shock mount was replaced with the Alpha tri-fold. The nose cone is probably one of the earliest that still exists. Our copy of it is the BNC-60LV which is slightly different from other BNC-60L nose cones from the early days. The later Berthas replaced the balsa nose cone with plastic and tended to be more elliptical than ogive. The plans for the Big Bertha were published in April, 1963, but it was not released as a kit until 1965. I always thought engine sales were the reason. Why sell a rocket that uses just one engine when you already have one that looks just like it that uses three engines?

And, yes, the SLS Brighton is an upscale of the Ranger, the original Bertha, which is German for "bright." The Semroc Vega was a clone of the earliest plans for the Big Bertha which had a much more ogive nose cone. Now I realize it was drafting error and not the correct shape that was actually used. The Semroc Goliath came after the Vega and shared the same parts. For the same reason, we discontinued the Vega around 1969 to sell more engines with the Goliath.
In the early 80s, I found a hobby store w/ orig. white(craft) tubes,-in the purchase, i got & still have several EARLY Bertha BNC's, every one of the BT-40 Nose cones(Aerobee hi too), Bt 40 & 30 BTs , BNCs,Clear Payload Sections-they're THICK & HARD!, nose blocks-several of each. A collector's dream ! The payload sections still have yellowed cellophane holdin em together, though some have fallen off. Inside the clear is the old serial # paper w/screw eye. They;re a lot of fun to have. dannymrmissile.

[mojo1986]

Or the original Apogee with the 18mm shorty motors. ;)

Wow! I didn't know that! So, the original Apogee used 2 shorty motors, and the Apogee II used the longer 2.75" ones that are common today?

[mojo1986]

It'd be interesting to know what Estes most popular (by sales) rocket has been over the years. The 'Bertha been produced for quite a while now.

The Astron Alpha, by a landslide. In production almost as long as the Bertha, simple and inexpensive, and offered in so many ways.............

As a single kit

In Starter kits

In FROGS educator kits

In later years, by the dozen.

[foamy]

The Astron Alpha, by a landslide. ...snip

Thanks for the answer. It's interesting. I'll have to get around to building one some day—kinda like I did with the 'Bertha.

[tbzep]

Wow! I didn't know that! So, the original Apogee used 2 shorty motors, and the Apogee II used the longer 2.75" ones that are common today?
I need to correct myself. I got the original Apogee mixed up with another classic two stager, the Astron Beta.

[Doug Sams]

I need to correct myself. I got the original Apogee mixed up with another classic two stager, the Astron Beta.Well...I was wondering about that, but couldn't find any info to contradict it - no Apogee 1 plans on-line, and the Ninfinger catalog page for the Apogee 1 doesn't list motors. So you coulda just about gotten away with it :)

Doug

.

[ghrocketman]

Agree with what tbzep said about the Bertha...it's large enough to be a decent demo rocket, and ugly enough to not care if it gets lost or beat up, therefore it is IMPOSSIBLE TO LOSE short of flying it on an engine larger than a H250G. :eek: :) :D :p

[jeffyjeep]

I thought that name sounded familiar. I've built only one Ranger (the 24mm one from the 1980's.) Yes, the NC was also used on the Exocet and at least one other model I believe. This Ranger is 100% hand painted (never again!)

Hence:

[tbzep]

Well...I was wondering about that, but couldn't find any info to contradict it - no Apogee 1 plans on-line, and the Ninfinger catalog page for the Apogee 1 doesn't list motors. So you coulda just about gotten away with it :)

Doug

.
Shockwaverider or some other motor historian would probably be able to tell us when the Series III became available and that would likely tell us for sure. I know the Series III was availabe as early as 1964.

I doubt the Apogee was ever set up for them because it would have to be gap staged to keep the booster length the same. Then again, maybe the booster was shorter?

[stefanj]

If you look at the very early Estes multi-staging technical report, they didn't yet "do" taped-together motors. Plans for the Aries II showed a considerable gap between stages, with a balsa thrust ring used as a coupler.

The Apogee "I" may have used a system like that.

[Doug Sams]

Shockwaverider or some other motor historian would probably be able to tell us when the Series III became available and that would likely tell us for sure. I know the Series III was availabe as early as 1964.

I doubt the Apogee was ever set up for them because it would have to be gap staged to keep the booster length the same. Then again, maybe the booster was shorter?The booster was indeed shorter. Here's a comparison drawing (http://www.doug79.com/apothree/Apogee1vs2-v4.pdf) I extracted from the various catalog pics. But I'm quite sure the Apogee 1 used regular length motors.

FWIW, Estes had shorties by 64. Looks like Centuri had them in 65, but carried only some of the available types. The 61 Estes catalog shows no shorties. No more Estes data until 64. The 62 and 64 Centuri catalogs show no shorties. (No 63 catalog available.)

It's never been clear why Estes stretched the Apogee (into the 2), but I suspect the booster was stretched (+~0.85") to encase the motor thus ensuring the booster stage separated along with the motor at staging - ie, to avoid fried boosters.

Doug

.

[Mark II]

I thought that name sounded familiar. I've built only one Ranger (the 24mm one from the 1980's.) Yes, the NC was also used on the Exocet and at least one other model I believe. The third kit to use the PNC-55EX was the Neptune (http://ninfinger.org/rockets/catalogs/estes85/85est40.html).

[Mark II]

It's never been clear why Estes stretched the Apogee (into the 2), but I suspect the booster was stretched (+~0.85") to encase the motor thus ensuring the booster stage separated along with the motor at staging - ie, to avoid fried boosters.

Doug

.The story that I read was that the original Apogee design was unstable. I'm sure that I saw that explanation here on this forum, some years ago.

[Doug Sams]

The story that I read was that the original Apogee design was unstable. I'm sure that I saw that explanation here on this forum, some years ago.I wanna say I've heard that, too. But I was a little skeptical - with the Bertha style fins, it's a little hard to believe.

That said, maybe, with some of the then new motors coming, they were anticipating stability problems as the new motors entered the market.

Doug

.

[Mark II]

I wanna say I've heard that, too. But I was a little skeptical - with the Bertha style fins, it's a little hard to believe.

That said, maybe, with some of the then new motors coming, they were anticipating stability problems as the new motors entered the market.

Doug

.One way to find out is to try to build one, estimating the part dimensions as closely as possible.

[CPMcGraw]

Looking at the 1960 catalog, there were only A8 and B8 engines available. Even by 1961, the largest engines were B8's and B16's. But, in 1964, the first C8's were introduced. A C engine is heavier, so it would have placed more mass behind the CP. With the shorter airframe, it might have become unstable, with or without the payload section. Remember, in the 63 ad, it was suggested the rocket could fly without the payload section, and I'll bet someone tried it with a C-C or a C-B combination, and got a whirlygig...

[Mark II]

Oddly, no engines are listed in the 1963 Estes catalog.

From their introduction in 1964 until 1968, the only Estes C engine was a booster.

(Weird thing about the 1968 Estes catalog on Ninfinger: there is no link on the Contents page to the Rocket Engine Selection Chart. In order to find it easily, click on the link to the Electro-Launch page. Then hit "Previous page" twice. Then hit "Next page" once. :rolleyes: If you hit "Next page" again, it will reveal another "hidden" page from the catalog. Bizarre. You can get those pages if you are moving forward through the catalog, but not if you are moving backward through it.)

[Mark+3]

Oddly, no engines are listed in the 1963 Estes catalog.

From their introduction in 1964 until 1968, the only Estes C engine was a booster.

I believe the reason C engines might have been boosters only during that time is that they may have been the "thick wall" Mabel I casing. This would not have left room for the delay/ejection charge.

Anyone with first hand knowledge to confirm or rebut this?

[ghrocketman]

The early C-booster engines were thick walled, and had quite a bit less total impulse than the C6 we have now.
Can't remember what the catalog quoted as the impulse but seem to recall they were like only 7n-sec in reality.

[Doug Sams]

The early C-booster engines were thick walled (snip) Yes, that's what I've always heard, that the reduced volume in the thick walled case left no room for delay or ejection charge - hence, booster-only C motors.

Doug

.

[Mark+3]

Can't remember what the catalog quoted as the impulse but seem to recall they were like only 7n-sec in reality.

C8-0 1.5lb/sec = 6.67n/sec

[Mark II]

C8-0 1.5lb/sec = 6.67n/secStill a C, just not a full C.

The lack of internal space explanation does make sense. I don't know if the thinner walled casings started being used as early as 1968, though. Wish I still had some from that era. I somehow had the impression that Estes started using the current casing dimensions at around the same time that they came out with the D motors and the mini motors, in the 1970-71 time frame.

[Doug Sams]

Still a C, just not a full C.

The lack of internal space explanation does make sense. I don't know if the thinner walled casings started being used as early as 1968, though. Wish I still had some from that era. I somehow had the impression that Estes started using the current casing dimensions at around the same time that they came out with the D motors and the mini motors, in the 1970-71 time frame.Mark,

The C6-0/3/5/7 was first out in 1968. That would imply thin walled casings. It also coincides with the advent of the metric motor designations. So the thin walls and metrics came out together.

The minis and D's came not long after.

Doug

.

[Mark II]

Mark,

The C6-0/3/5/7 was first out in 1968. That would imply thin walled casings. It also coincides with the advent of the metric motor designations. So the thin walls and metrics came out together.

The minis and D's came not long after.

Doug

.I am aware of the sequence of releases. I would have assumed that the modern casing was introduced with the new C6s in 1968. I thought I heard awhile back that Estes didn't start using these casings until the early 70s, though. Back in 1968 or '69 I had B and C Estes motors. I also had Series III motors and pre-metric motors from my 1967 starter set. I wish I still had them so that I could check this out. At the time, I didn't notice any differences at the time, but that doesn't mean that there weren't any. I do remember the casing walls on my first motors being quite thick, though.

I remember when Estes came out with the D motors in 1970. They were the biggest model rocket motors that I had ever heard of. I thought of them as super-motors but I never got around to buying any of them during the next year. I suspended my involvement in the hobby mere minutes (only a slight exaggeration) before Estes announced their new mini T motors in 1971. Talk about perfect timing. :rolleyes:

[vulcanitebill]

The C6-0/3/5/7 was first out in 1968. That would imply thin walled casings. It also coincides with the advent of the metric motor designations. So the thin walls and metrics came out together.


This is my memory of it as well. Most of my early flying was about 1965-1969. I built a Ranger back then and launched it with both series I and series II B's. Those were the thick walled engines and a B filled the available space, no room for enough propellant for a C with delay and ejection charge.

I remember when the Big Bertha came out, one of my friends built one. It did have the low and slow majestic flight characteristic, and I wasn't interested in it for that reason. Plus it wasn't very sleek with the blunt nosecone. Nowadays a BB would fly very well on a modern C engine. I'm actually planning to build a BT60 rocket, maybe a Vagabond, to use for D12 motors.

We built models with the BT10 and BT30 tubes in those days. I had forgotten about the BT40 tube but I still have one model made with it, the BT40 is not much bigger than the BT20 motor mount tube. I remember when the BT55 tube came out and I built a scratch built design with it. I thought this was a good tube for a B, slightly faster than a BB.

Estes didn't have C single stage engines back then but at some point in time we discovered FSI engines and they had a C. It was bigger than 18mm, maybe 20mm or 21mm. I tore the motor mount out of my BT55 model and made a motor mount just to fit the FSI engines. Now that I think about it it might have used the BT40 to hold the motor.

As a kid we had made our own launch system using dry cell batteries, so we could carry it out into my grandfather's pasture. When I launched my Ranger we had someone drive us to a different launch site and we used their car battery for power. This is another advantage of a single motor over a cluster.

[Mark II]

I neglected to add to my previous post that in light of the explanation that Doug provided, I stand corrected regarding the introduction of the thinner-walled Estes engine casings. It obviously had to have been 1968, because the C6 motors with delays and ejection charges that were introduced that year could only have fit into casings with the current (thinner) inner diameter.

I can easily see how a BT-40 could be used as a motor tube for a 21mm FSI motor. I don't have any samples of 1960s Estes Industries BT-40 to verify it, but assuming that Semroc's version is faithful to the original, a 21mm motor could conceivably be just gotten into it with a very snug fit. I use BT-40 for homemade motor adapters for Quest D5 motors, which are nominally 20mm in diameter. I have to slit the tube down the side to get the motor to fit in, but that might be partly due to the loose-fitting paper label on it. (The ID of Semroc BT-40 is actually 0.022" smaller than 20mm, so this might be necessary anyway.) With the slit BT-40 glued inside a length of Series 085 tubing (LT-085) and the gap caused by the slit blocked with a little bit of epoxy putty or JB Weld, I have a 20mm to 24mm adapter that is dirt-simple to construct.

[blackshire]

There might be a way around this cluster ignition problem. Similar to the way the Estes MIRV uses a trifurcated vent to direct the single 18 mm first stage motor's hot burn-through particles into the nozzles of its three 13 mm second stage motors, a "spider pan" (as the Russians call a similar black powder vented-flame "flash pan" system that ensures ignition of all of the Soyuz rocket's thirty-two core stage and booster thrust chambers) could ignite the Ranger's three motors using just a single igniter. It could be arranged thus:

The "spider pan" could be made of ceramic or metal. A little black powder or pyrodex would be poured into it, and it would be placed on the launcher's jet deflector (held in place using a stand-off bracket that would be slid down the launch rod to keep it from falling off the jet deflector) with its three vent tubes aimed into the motors' nozzles. A standard Estes or Quest igniter would be installed inside the spider pan, with its leads protruding through two small holes in the side of the spider pan. It could be made in two threaded sections (upper and lower) that would facilitate igniter installation & removal, filling the lower section with black powder or pyrodex, and cleaning the spider pan after use.

[Mark II]

The early C-booster engines were thick walled, and had quite a bit less total impulse than the C6 we have now.
Can't remember what the catalog quoted as the impulse but seem to recall they were like only 7n-sec in reality.Correct, as Mark+3 previously noted. Here are the links to the catalog pages. The C.8-0 booster motor (http://www.ninfinger.org/rockets/catalogs/estes67/67est44.html) in the 1967 Estes catalog is shown as having 1.50 lb.-sec. of total impulse. The C6-x motors in the 1968 catalog (http://www.ninfinger.org/rockets/nostalgia/68estp48.html) are listed as having 2.25 lb.-sec. of total impulse. This translates to 6.675 N-sec. for the 1967 motor and 10 N-sec. for the 1968 C motors. Quite a difference.

[vulcanitebill]

I can easily see how a BT-40 could be used as a motor tube for a 21mm FSI motor. I don't have any samples of 1960s Estes Industries BT-40 to verify it, but assuming that Semroc's version is faithful to the original, a 21mm motor could conceivably be just gotten into it with a very snug fit.

I was trying to reconcile bits of my memory and I think I jumped to incorrect conclusions. I just took some measurements and that changes my conclusions.

I thought I remembered hand rolling a paper tube to use as a motor mount. The motor tube in the rocket is thinner than normal Estes tubes, but smoother on the inside than I would have expected myself to make at age 14 or so. The ID of this tube is 0.945" and as I recall it fits the FSI engine about like an Estes BT20 fits their 18mm engines, or maybe a bit larger. That should be a good gauge of what the FSI engines required.

I knew that the other rocket that I still have used a tube somewhere in between BT20 and BT50, and I had forgotten about BT40 until I read this thread. This rocket has centering rings at the back end and a balsa adapter glued into the front end so I can't measure the ID. The OD measures about 0.905".

So obviously my FSI engine mount doesn't use a BT40.

[blackshire]

I think the BT-40 was an "adopted" tube size, from leftover MMI (Model Missiles, Inc.) body tubes for their Aerobee-Hi and Arcon kits that Estes acquired when MMI went bust. Estes also sold the vinyl MMI Aerobee-Hi/Arcon nose cones at that time.

[vulcanitebill]

I think the BT-40 was an "adopted" tube size, from leftover MMI (Model Missiles, Inc.) body tubes for their Aerobee-Hi and Arcon kits that Estes acquired when MMI went bust. Estes also sold the vinyl MMI Aerobee-Hi/Arcon nose cones at that time.

I have one of those long vinyl nose cones, and the one that I have fits a BT30.

[blackshire]

I have one of those long vinyl nose cones, and the one that I have fits a BT30.Here is a 1965 Estes Free Plan for an Aerobee-Hi that used BT-40 (see: http://www.spacemodeling.org/JimZ/eirp_32.htm ). It used a vinyl nose cone whose designation was PNC-40G. I wonder if your nose cone might be one of the leftover firework missile parts that Estes Industries sold in the early days (Vern Estes was in the fireworks business before he founded Estes Industries)?

[Royatl]

Thanks for the answer. It's interesting. I'll have to get around to building one some day—kinda like I did with the 'Bertha.

Though I've heard from good sources that over the past few years the Hi-Flyer is the big seller.

[Royatl]

Note that prior to 1968 and the metric conversion, the NAR Total Impulse chart was a bit different.

It didn't nicely double over the whole range.

1/4A 0 - .175 lb-sec
1/2A .176 - .350 lb-sec
A .351 - .700 lb-sec
B .701 - 1.200 lb-sec Whoops!
C 1.201 - 2.00 lb-sec Whoops! again!
D 2.01 - 4.00 lb -sec ah, back to doubling
E 4.01 - 8.00 lb-sec
F 8.01 - 16.00 lb-sec

[blackshire]

Though I've heard from good sources that over the past few years the Hi-Flyer is the big seller.Due to its large fin area and Center of Pressure/Center of Gravity relationship, the Hi-Flyer can be (like the Estes Phoenix missile scale kit) one of Estes' more...exciting rockets to fly, especially on the heavier "C" motors that move the CG more rearward--"No two flights the same!" :-)

[gpoehlein]

Though I've heard from good sources that over the past few years the Hi-Flyer is the big seller.

I will say that I have purchased a large number of Hi-Flyers myself. I've only built one as a Hi-Flyer, and that one was built with a 13mm motor mount. Why did I buy so many of them (and continue to do so)? Two reasons - it is cheaper than any other BT-20 based rocket ($6-7 as opposed to $8-9 for a Wizard or Viking) and the body tube is a bit longer than that in the Wizard or Viking. Thus, the Hi-Flyer is really good for kit bashing into various types of contest models (18mm boost glider pods, egg-on-a-stick boosters, quick and dirty streamer duration models, etc.). Because of the price, that sucker's just a kitbasher's dream!

Greg

[Doug Sams]

So obviously my FSI engine mount doesn't use a BT40.Could it have instead been an Estes motor shipping tube? These were usually light blue, and should have been about the right size for the FSI motor.

Doug

.

[Mark II]

I was trying to reconcile bits of my memory and I think I jumped to incorrect conclusions. I just took some measurements and that changes my conclusions.

I thought I remembered hand rolling a paper tube to use as a motor mount. The motor tube in the rocket is thinner than normal Estes tubes, but smoother on the inside than I would have expected myself to make at age 14 or so. The ID of this tube is 0.945" and as I recall it fits the FSI engine about like an Estes BT20 fits their 18mm engines, or maybe a bit larger. That should be a good gauge of what the FSI engines required.

I knew that the other rocket that I still have used a tube somewhere in between BT20 and BT50, and I had forgotten about BT40 until I read this thread. This rocket has centering rings at the back end and a balsa adapter glued into the front end so I can't measure the ID. The OD measures about 0.905".

So obviously my FSI engine mount doesn't use a BT40.The Quest D5 motors are 20mm in diameter (0.787"), FSI's A4, B3, C4, D4 and E5 motors were 21mm in diameter (0.827"). Their E60, F7 and F100 motors were 27mm in diameter (1.063") and their A6, B6 and C6 motors were 18mm (0.709") in diameter. When I was thinking about the possibility of using BT-40 for motor tube, I was extrapolating from the fact that I use it for the 20mm Quest D5 motors. But I was incorrect because the FSI motors wouldn't have fit. The best fit in existing tubing would have been in Centuri ST-8, which had an ID of 0.865" and an OD of 0.908". This was a commonly-available tube and is probably what you used. I never had any FSI motors so I have no experience with adapting them to fit into a motor mount.

FSI themselves used RT-8 as a motor tube for their 21mm motors. This had an ID of 0.885" and an OD of 0.921". Throughout most of their catalogs, the company incorrectly labeled RT-8 as "0.903" tubing." I have no idea how they derived that number, but it doesn't match any dimension of RT-8.

Did you mean to say that 0.945" was the outside diameter of your old tube? If so, it matches the OD of Semroc Series 085 tubing. It would have been a perfect fit inside 24mm motor mount tubing, such as Estes BT-50.

[Mark II]

Could it have instead been an Estes motor shipping tube? These were usually light blue, and should have been about the right size for the FSI motor.

Doug

.From what I have read, Estes motor shipping tubes were just a smidgen larger on the inside than the diameter of the 18mm motors. I would think that it would have been too small to accommodate a 21mm FSI motor.

[Mark+3]

For reference: the Estes motor shipping tube I have is blue and parallel wound with an
ID (min)~ .92" and an OD (max) ~ 1.04". I'm giving the dimensions as min. and max. due to parallel winding of tube. Were Estes stated dimensions of BT-30 minimum and maximum diameters or average diameters? Min./Max. seems more logical.

[Royatl]

From what I have read, Estes motor shipping tubes were just a smidgen larger on the inside than the diameter of the 18mm motors. I would think that it would have been too small to accommodate a 21mm FSI motor.

no, the shipping tubes have to accomodate the instruction sheet as well, which was thin paper, but nearly the size of regular notebook sheet, plus the strip of "astron" igniters. The 18mm motors rattled around easily. Also, IIRC, the packing slip would be rolled up inside if the order was for individual motors, say, a 1/2A.8-4, a B.8-4, and a B3-0 in the same tube.

[Mark II]

Granted, I never saw an Estes motor shipping tube. All of my motor orders from the company were for very small numbers of individual motors, and they were rolled up in newspaper and packed in the box with my kit orders. None of mine were ever in tubes.

[dannymrmissile]

This is my memory of it as well. Most of my early flying was about 1965-1969. I built a Ranger back then and launched it with both series I and series II B's. Those were the thick walled engines and a B filled the available space, no room for enough propellant for a C with delay and ejection charge.

I remember when the Big Bertha came out, one of my friends built one. It did have the low and slow majestic flight characteristic, and I wasn't interested in it for that reason. Plus it wasn't very sleek with the blunt nosecone. Nowadays a BB would fly very well on a modern C engine. I'm actually planning to build a BT60 rocket, maybe a Vagabond, to use for D12 motors.

We built models with the BT10 and BT30 tubes in those days. I had forgotten about the BT40 tube but I still have one model made with it, the BT40 is not much bigger than the BT20 motor mount tube. I remember when the BT55 tube came out and I built a scratch built design with it. I thought this was a good tube for a B, slightly faster than a BB.

Estes didn't have C single stage engines back then but at some point in time we discovered FSI engines and they had a C. It was bigger than 18mm, maybe 20mm or 21mm. I tore the motor mount out of my BT55 model and made a motor mount just to fit the FSI engines. Now that I think about it it might have used the BT40 to hold the motor.

As a kid we had made our own launch system using dry cell batteries, so we could carry it out into my grandfather's pasture. When I launched my Ranger we had someone drive us to a different launch site and we used their car battery for power. This is another advantage of a single motor over a cluster.
Just happened to be goin thur my old Bt 40s last nite. Have small bx full & clear payload sections, etc. Were durable & fun indeed. dan.

[foamy]

Granted, I never saw an Estes motor shipping tube. All of my motor orders from the company were for very small numbers of individual motors, and they were rolled up in newspaper and packed in the box with my kit orders. None of mine were ever in tubes.
I built more rockets out of the motor tubes than I ever built from kits. Usually of the one flight variety.

[Doug Sams]

I built more rockets out of the motor tubes than I ever built from kits. Usually of the one flight variety.Oh, so the real terrorists come out :) (j/k)

Doug...who only fantasizes about horizontal flight...

.

[Mark II]

I built more rockets out of the motor tubes than I ever built from kits. Usually of the one flight variety.You must have bought a lot of motors!

[foamy]

Bought a lot of motors? No, not really. As a kid on a very limited budget, I could buy a kit or a tube of motors. A tube of motors came with it's own essential building block for a rocket. Very conveniently sized. I don't believe I ever let one go to waste. I didn't operate like that all the time and of course, these things weren't works of art, but they did (mostly) fly and I learned a good bit (good and bad). Again, as a kid, when I went out to launch, I didn't come back until I ran out of motors or rockets. Sometimes both.

[Mark II]

How many motors did a tube contain? The most motors that I ever included in a single order were three (or possibly four), and no two were alike. But I never received them in a tube. In fact, I didn't know that Estes had ever packaged motors in tubes until after I brought my model rocketry hobby out of suspended animation in 2004.

[BEC]

The tubes held three motors. Sometimes an order that had more motors would come as multiple tubes, all separately addressed and with separate postage....bound together with rubber bands.

I don't recall if they put more than three shorties (Series III) motors in a tube or not.

[Mark+3]

I don't recall if they put more than three shorties (Series III) motors in a tube or not.
The tube of shorts in my collection has 3 series III motors, rolled instructions, ignitors, and one standard length (2 3/4") dummy engine casing (thin wall).

[BEC]

That makes some sense. Somewhere in one of the regulatory discussions on this board I remember reading that at one time the postal regs only allowed three motors "in a package". Hence, the three-motor tubes - often bundled together. Each WAS a separate package - it could travel separately as it was separately addressed and stamped.

Of course back then I didn't care about all of that - I was just glad to have the motors sent from southern Colorado to our post office box in NW New Mexico :).