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.

__________________
Carl McLawhorn
NAR#4717 L2
semroc.com

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

.

__________________
YORF member #11

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.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

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!

__________________
John A. Lee O.S.L.
Alamo Rocketeers NAR Section 661
NAR 87285, L1 8 March 2008
TRA 03040, L1 8 March 2008
Photos of the "Fleet": http://www.flickr.com/photos/23694991@N03/

I used to tell Mom, "...I want to fly rockets when I grow up!"

She said, "Make up your mind, you can't do both!"

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.

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.

__________________
Retro-grouch

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.

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.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

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

.

__________________
YORF member #11

Interesting comment from Mr. "INDIVIDUAL FREEDOM".



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

__________________
Bernard Cawley
NAR 89040 L1 - Life Member
SAM 0061
AMA 42160
KG7AIE