Bigger Bertha

[lessgravity]

I was looking around my Rocket Shed wanting to do a new scratch build. My eyes fell upon a tube that measured about 2.8 inches in diameter and was thick walled. Then my eyes fell upon my old trusty Big Bertha.
Upscale!
I created this fun upscale I call the Bigger Bertha. It is about 25% bigger than a Super Bertha and should fly nice on G's. It's 29mm and will be a nice mid-range Rocket. Next step will be a 4 inch diameter Bertha I plan to build this summer.

I plan to fly her on Saturday at our club launch if the weather holds.
Here she is next to my Big Bertha:

 

[Luv2launch]

Nice one I been wanting to do an upscale bertha for awhile now, where did you get the nosecone is it a custom?I was thinking doing a Bertha in a 3 inch diameter.

 

[jimzcatz]

Back in the day,Bob Sisk buile a 7.5" BB. Did his L3 with it. Sandman from Roachwerks is who I recommend for the noses. They are tha same as mosquitos,only bigger.

 

[lessgravity]

Nice one I been wanting to do an upscale bertha for awhile now, where did you get the nosecone is it a custom?I was thinking doing a Bertha in a 3 inch diameter.

Did the nosecone myself. Balsa layers turned on my drill press (works pretty well as my lathe). I'm sure you can get one from Sandman as Jim mentioned.

Jim - I would love to have seen the the 7.5'' BB.

 

[wickball]

I believe you're pretty close to the size of a Super Big Bertha, it was based on a BT-80, about 2.6 inches.

wick

 

[lessgravity]

I believe you're pretty close to the size of a Super Big Bertha, it was based on a BT-80, about 2.6 inches.

wick

Yes the Super Bertha is about a 150% build and mine is about 175% at 2.884 inches in diameter. It much heavier also because of the thick walled tube.

 

[aerospike]

Performance Hobbies (not Performance Rocketry) will soon have a 4" version of the BB.

 

[lessgravity]

Performance Hobbies (not Performance Rocketry) will soon have a 4" version of the BB.

Yes - Ken was there to see my launch this weekend and we discussed the 4 inch model.
Here is a picture of mine on the pad. A friend caught a takeoff picture and is sending to me today. I'll post then.

 

[rsynoski]

How about this for an up-scale.

 

[lessgravity]

How about this for an up-scale.

That works for me!
What are the measurements?

 

[rsynoski]

That works for me!
What are the measurements?

The BT is 6" PML

 

[DaveCombs]

How about this for an up-scale.

The real trick is this: It's a regular Bertha next to a plastic model 350Z, and he actually downscaled the house, driveway and palm trees!

Really nice Bertha. I'm a big upscale fan too.

 

[lessgravity]

As promised here is a picture as she leaves the rail

 

[Boosterdude]

Looks, and flew great Wayne!

 

[foose4string]

Looks good LG!

How about this for an up-scale.

Adds new meaning to the words "Big" Bertha.

How about this one built by fellow club member, Jim Cox? Flew beautifully on an M motor, recovery was another matter entirely. That's me holding the normal sized Bertha for size comparison.....

 

[zog139]

Lo That's me holding the normal sized Bertha for size comparison.....

Craig am I confused again ? That does not look like you in the photo ?

 

[rokitflite]

Thats scary hairy Craig Jim... Remember, he plays in a band.