Super Big Bertha and Downscale Baby Berthaa

[johnnwwa]

I'm Building a series of Estes Bertha rockets. My questions are this.

1. The SSB uses a D12 I'm thiking of using a E9-4 . the D12-3 seems a little wimpy to me? Has anyone installed this motor in the SSB?

2. Are there any downscale plans for a Baby Bertha BT50 or BT20 and BNC to match?

Any building tips on SSB or downscale Baby Bertha would help.
By the time I get done with this project I expect to have four to five completed rockets. In my Bertha family.

Thanks
BAR
John

 

[rabidsheeep]

never have built one, but i guess to use an E motor you would just need to do what you do to everything, which is set the motor block alittle farther back and add alittle noseweight to counter it

im sure sandman could make you a worthy nosecone... i dont know of any other estes ones that are matches of the big berthas

 

[BobH48]

Estes used to make a Mini-Bertha based on a BT-20.

The plans are on Jim Z's site here:

https://www.dars.org/jimz/est0803.htm

The nose cone from the parts list is a BNC-20L

BMS has a BNC-20L listed.

 

[Stymye]

John,in this case the D12 is not wimpy at all, it has more kick than the E9,, the E9 just has the impulse stretched out for that great long burn time..

you could build it for the E and fly it on D's just as well

 

[billeblurzz]

John, build the SBB with the longer E motor mount. One of my favorite flyers...slow realistic liftoffs and recovery on a small field with a nylon 24" chute!

 

[billeblurzz]

Liftoff on E9-4:

 

[billeblurzz]

I also added 1 oz. clay nose weight and be sure to add 2-3 times the body length for elastic shock cord to prevent the "Estes dent"! ....long shock cords also LOOK cool!

 

[xenon]

When I built mine, I built it with the D mount. Later, I got into E and F composite motors. I haven't added any nose weight to mine and it flys fine with a F12 hanging out the back. I also flew it a few times CHAD staging a D12 to a E9 Nose weight probably isn't nessesary with the big fins, but I'd check the CG anyway

 

[Fore Check]

Estes produced a kit called the Broadsword that was simply a Super Big Bertha with an E engine mount (rather than a "D"). A very similar situation to the Optima and Shadow models.

If your cloning, you can use the Broadsword plans available on JimZ's and just finish it as a SBB. Or, you could wait until YORS updated their site for SBB plans and decal scans (I sent them in a month or two ago.)

What I'm getting at: As billEblurzz testified with his launch photos, the SBB does fine on an E mount. When I do finally get around to building mine, I'm sure I'll go with a cluster of either 2 or 4 E engines (knowing that nose weight will be necessary if I go with 4.)

 

[johnnwwa]

Actually I have a SSB Estes kit so as far as cloning goes it's a no brainer but thanks for the info. my main concern was weather or not I needed nose weight. I'll be building this one to take E or D motors . I picked the kit up last year for 24.99. I really love these Bertha rockets. Also looking forward to the Goony series I have three Baby Berthas set aside for just for the Goonies. Need two more .
BTW best place I've found to buy these is www.hobbylinc.com @ 4.69 ea.

BAR
John

 

[astronboy]

I built my SBB with an 'E' length mount, no extra noseweight, an 24" nylon chutre, and and fly it with AT E15s. here is a launch pic::

https://tinyurl.com/5o3uo

Phred

 

[powderburner]

Originally posted by rabidsheeep
i dont know of any other estes ones that are matches of the big berthas

I think the Estes Fat Boy nose cone is the right one to use for a Super BB or a Broadsword.

 

[gpoehlein]

Yes - the Fat Boy nose cone is the right nose for the Super Bertha/Broadsword. I "kitted" the super bertha out, down to a simulated header card and cover page for my dad for father's day - he really loved it - I got him hooked on rockets last year, then he saw the Discovery series and he's caught the "bigger is better" disease!

Making the "kit", I used the two BT-80 tubes that come in the Estes tube package (I used that package as well - carefully slit open the top, packed everything into it, and re-sealed it with a Seal-A-Meal!) I "die cut" (mostly cut out with an xacto, leaving 1/8" strips near the corners) the fins, included the centering rings from two Fat Boys, the proper length of BT-50 for the stuffer tube, the chute and nose cone from one of the Fat Boys, and made a CT-80 coupler out of part of one of the Fat Boy body tubes. A carefully printed set of instructions was photocopied at work onto 11 x 17 pages, and I took some full page Avery clear mailing label stock and made the decals for it.

Of course, you could always just use an Executioner (same BT length, stuffer tube, etc.), use the nose from a Fat Boy and make new fins. Everything else you'd need is there.

Greg

 

[mike_bar]

Originally posted by powderburner
I think the Estes Fat Boy nose cone is the right one to use for a Super BB or a Broadsword.

I agree with powderburner. I have a Fat Boy kit on my desk. The nose cone is part number PNC-80BB. Would that be a Big Bertha BB? I looked at the Broadsword plans at the JimZ Website. All it says there is “nose cone.”

Check out this other thread regarding the Fat Boy: Fatboy: choices, choices, choices!

My thought is to build a two-stage Fat Boy as Rob Wegner has done. Then, with the extra nose cone build a Super Big Bertha.

It’s a two-fer!

Mike