The return of the Super Big Bertha

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BEC

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It IS fun.

John Boren gifted me with a bag of parts at NSL and I put it together and have flown it (in primer). It's a great use of the 29mm Estes black powder motors and flies just like you'd want a Big Bertha to fly. As with the Star Orbiter, there is no motor block so it is very flexible (and you have to put a tape thrust ring on the BP 29mm motors - which is no big deal).

I need to get it finished while we still have painting weather.....

Then, next year when I'm over at a bigger flying site, perhaps a little bit more motor than an F15.... :D
 

viciouspeanut

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Interesting - Wish it was the heavy wall tubing but I understand that are getting away from that (probably). Will still probably grab one, a 40-120 case wouldn't beat up on it too much I hope?
 

mrwalsh85

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Interesting - Wish it was the heavy wall tubing but I understand that are getting away from that (probably). Will still probably grab one, a 40-120 case wouldn't beat up on it too much I hope?
A quick wrap of 2oz should help!
 

EXPjawa

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I built a similar rocket a few years ago, somewhere between a Super Bertha clone and BB upscale (which aren't exactly the same thing, structurally). I built it with a 29mm mount, and have flown it on F20 SU motors pretty well, though I mostly use 24mm E20 or E30s in it. The rocket's biggest issue is the long overhang on the fins makes them susceptible to landing damage; they break cross-grain, diagonally up from the bottom of the body tube (you can see a repair scar in the photo). Hopefully, this design's built up fins help that, but I'd have rather seen the core layer be basswood or lite ply...

 

rstaff3

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Interesting - Wish it was the heavy wall tubing but I understand that are getting away from that (probably). Will still probably grab one, a 40-120 case wouldn't beat up on it too much I hope?
Easy solution....Chute release and a big a$$ chute. But the Mega Skeeter's fins seem to do fine. Oh, wait, I still have an oversized chute. :wink:

Edit: I was still hung up on landing issues. My gut says the three layer fins will hold up to a G. But still get that chute releads :D
 
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EXPjawa

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Easy solution....Chute release and a big a$$ chute. But the Mega Skeeter's fins seem to do fine. Oh, wait, I still have an oversized chute. :wink:

Edit: I was still hung up on landing issues. My gut says the three layer fins will hold up to a G. But still get that chute releads :D
Well, that is how I fly now. But it wasn't always...
 

BEC

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Just to add a little detail....the cores are 1/8 inch balsa, the skins are 1/16. The resulting 1/4 inch thick sandwich is quite stout. Certainly if one doesn't add a bunch of mass trying to "improve" it with metal hardware and fiberglass it will land softly enough on the supplied 24 inch 'chute. My two E16 flights so far touched down at 13 feet per second per AltimeterThree aboard.

A Chute Release will be perfect for flying this on something more than the Estes F15s.
 

Woody's Workshop

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If you going to use more than BP engines, I'd order some (or make) plywood centering rings.
I would worry the card stock wouldn't hold up.
Back in the day, a BP Estes D blew the card stock out of my Scratch Built (BT-55) Stinger and to rebuild it.

Viper & Stinger.jpg
 

EXPjawa

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Just to add a little detail....the cores are 1/8 inch balsa, the skins are 1/16. The resulting 1/4 inch thick sandwich is quite stout. Certainly if one doesn't add a bunch of mass trying to "improve" it with metal hardware and fiberglass it will land softly enough on the supplied 24 inch 'chute. My two E16 flights so far touched down at 13 feet per second per AltimeterThree aboard.

A Chute Release will be perfect for flying this on something more than the Estes F15s.
Good to know; my previous Bertha had only 1/8" thick balsa fins IIRC. The sandwiched structure sounds much improved.
 

Tonimus

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Could always go full length coupler, too.
 

EXPjawa

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Could always go full length coupler, too.
I'm just pleased that they appear to have updated it with a better tube coupler. The original kit had one that was only 1" long. The only change I think I'd make would be to replace the top ring with a plywood one, so better to attach a kevlar lead to. As a side note, we ought to have a contest to see what other designs people might come up with to use the cut-out sections of the fin sandwich as fins on a smaller rocket...
 

justinwebb

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I still have the original in a box somewhere in the garage that I haven’t got around to building, cool to see them bring it back
 

Sooner Boomer

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I hate that nosecone. That's why I never bought a Big Bertha. I only bought the little ones to A) build a Baby Fat Boy, and 2) to prove one could be built "stock" and fly on a 29mm motor (and be recovered in one piece). YMMV...
 

mrwalsh85

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I hate that nosecone. That's why I never bought a Big Bertha. I only bought the little ones to A) build a Baby Fat Boy, and 2) to prove one could be built "stock" and fly on a 29mm motor (and be recovered in one piece). YMMV...
Slight thread derail - I'm hoping to fly my Mini Fat Boy on a G55 this weekend :p
 

rstaff3

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Slight thread derail - I'm hoping to fly my Mini Fat Boy on a G55 this weekend :p
Mine has only flown on F15s. I have a 6' streamer made from doubled over 12' piece of caution tape. Not a scratch after three flights. Twice it came back close but, on the last flight, I was lucky one guy was scanning the horizon behind us and saw it come down. Someday I will try to shred those fins.
 

HandsomeRob

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Ah cool!! Been kind of excited about this since I first heard rumors about it, I just may have to get one. I'm still partial to the all black berthas of the mid 90's. I like this red and white though.

That Red Nova looks kinda neat too.
 

ECayemberg

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Looking forward to the return of the Super Big!:)

I'm a bit perplexed by all the comments about beefing it up. Yes the BT-80 tubes are thin wall, and yes the stocker Super Big Bertha and Broadsword had 1/8" fins. I've had both, gave away the SBB after many years and many flights, and still have the Broadsword....built is many moons ago as a kid. After an infamous Estes E15 cato, the Broadsword was cobbled back together. Since the cato, it flies almost exclusively on Ellis G37's and Aerotech G55's...fun flights. No reinforcement, not built well, been through 2 catos now (an Estes E12 too:cyclops:) and still going strong (but ugly!).

Not saying y'all are wrong...I'm not! Only sharing personal experience with both....really one and the same except for the longer motor mount. My experience is that the stock SBB or BS don't need reinforcement for any 24mm motors. I do not treat them gently; once a rocket does something silly like cato or core sample, it immediately becomes an abuse hound that I try to lose/punish.

Now you wanna put an I200 in there, and you may want to reinforce slightly: maybe. However, I'd hedge a bet that I could fly the SBB new kit on an I200 (ok, I205 for disposability sake) without a touch of glass and without any additional balsa. Those thin wall tubes can handle more than people give them credit for!
 

cavecentral

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I need to reinforce all my rockets to survive the trip in the car with their fiberglass friends.
 

rstaff3

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Looking forward to the return of the Super Big!:)

I'm a bit perplexed by all the comments about beefing it up. Yes the BT-80 tubes are thin wall, and yes the stocker Super Big Bertha and Broadsword had 1/8" fins. I've had both, gave away the SBB after many years and many flights, and still have the Broadsword....built is many moons ago as a kid. After an infamous Estes E15 cato, the Broadsword was cobbled back together. Since the cato, it flies almost exclusively on Ellis G37's and Aerotech G55's...fun flights. No reinforcement, not built well, been through 2 catos now (an Estes E12 too:cyclops:) and still going strong (but ugly!).

Not saying y'all are wrong...I'm not! Only sharing personal experience with both....really one and the same except for the longer motor mount. My experience is that the stock SBB or BS don't need reinforcement for any 24mm motors. I do not treat them gently; once a rocket does something silly like cato or core sample, it immediately becomes an abuse hound that I try to lose/punish.

Now you wanna put an I200 in there, and you may want to reinforce slightly: maybe. However, I'd hedge a bet that I could fly the SBB new kit on an I200 (ok, I205 for disposability sake) without a touch of glass and without any additional balsa. Those thin wall tubes can handle more than people give them credit for!
Nothing beats first hand experience.
 

MALBAR 70

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All this talk of SBB and Broadswords got me to dig the Broadsword out of my tote and move it to the top of my build pile. I have a SBB too but I think I may just pick up a "new and improved" version when it's released.
 

viciouspeanut

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Well then I might build it stock and keep going higher and higher impulse to see when it gives out lol. Although then finding it becomes an issue.. Hmm
 

ECayemberg

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Well then I might build it stock and keep going higher and higher impulse to see when it gives out lol. Although then finding it becomes an issue.. Hmm
Sounds like fun! With all the interior room in the SBB, like others said, I think the JLCR is a good candidate for keeping it close in.

My old, battered Broadsword has the stock 24mm mount and 1/8" fins; I usually bring it down on a 18" nylon chute, or 15" thin mill if it's windy. No issue with breaking fins to date, but the thing is light!

Love the idea of a 29mm SBB...can't wait!!!
 

viciouspeanut

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Sounds like fun! With all the interior room in the SBB, like others said, I think the JLCR is a good candidate for keeping it close in.

My old, battered Broadsword has the stock 24mm mount and 1/8" fins; I usually bring it down on a 18" nylon chute, or 15" thin mill if it's windy. No issue with breaking fins to date, but the thing is light!

Love the idea of a 29mm SBB...can't wait!!!
I keep forgetting that thing exists... I will definitely have to try some interesting flights then. :D
 

Cabernut

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With all these cool kits coming out(coming back), I'll have to reinforce my wallet...
 

EXPjawa

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With all these cool kits coming out(coming back), I'll have to reinforce my wallet...
I know, right? As if the build pile wasn't big enough...

Anyone know if 3 29mm tubes will fit in a BT80, thereby converting one to a Ranger?
 
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