SBB(III)

[hambirm2018]

Another scratch build. I call it the SBBIII HP

 

[jqavins]

Nice. I have four (well, five) questions (for now).

1. In the fifth photo, is that a dry fit of the fins to the motor mount? The fin slots in the body tube don't extend to the aft end, so it seems like the body tube couldn't have slid down over the fins. Did you just skip posting pictures of the motor mount inserted before the fins went back on?
2. Why did you make the fins' skins in two pieces?
3. What's the recovery setup?
4. What motor(s) will she take?
   • What's the expected performance?

 

[hambirm2018]

Nice. I have four (well, five) questions (for now).

1. In the fifth photo, is that a dry fit of the fins to the motor mount? The fin slots in the body tube don't extend to the aft end, so it seems like the body tube couldn't have slid down over the fins. Did you just skip posting pictures of the motor mount inserted before the fins went back on?
2. Why did you make the fins' skins in two pieces?
3. What's the recovery setup?
4. What motor(s) will she take?
   • What's the expected performance?

It was a dry fit. I have used the thinner SBB II fins and sometimes they break off on landing so after I used the Vanderburn upgrades to up scale a previous Red Red Max. I decided to go with a 29mm HP. Some of the motors I’m looking at are G

 

[hambirm2018]

It was a dry fit. I have used the thinner SBB II fins and sometimes they break off on landing so after I used the Vanderburn upgrades to up scale a previous Red Red Max. I decided to go with a 29mm HP. Some of the motors I’m looking at are G

G88’s and above.

 

[hambirm2018]

G88’s and above.

The last picture of the rockets and drill is during the process I use to foam fin cans.

 

[hambirm2018]

2100ft is what I’m expecting. Recovery will just be single (motor ejection) deployment just with my version of kevlar harness/rings…

 

[lakeroadster]

She’s almost there!

Nice. Is the body tapered or is that an optical illusion? Nice stickers too.

 

[hambirm2018]

Just the angle but that would be cool. I also doubled the entire inside of the airframe with epoxy and couplers all the way to the motor centering rings.

 

[lakeroadster]

Using a full length coupler... I do that on most of my builds also. Did you know you can buy 34" long couplers from Balsa Machining Service?

Also, those hollow core ply fins are slick...

 

[hambirm2018]

Using a full length coupler... I do that on most of my builds also. Did you know you can buy 34" long couplers from Balsa Machining Service?

Also, those hollow core ply fins are slick...

View attachment 499492

No, I had no no idea they were sold! SBR had a fuzzie coupler I used and started go incoproate that technique in all my builds. Thanks for the 411!

 

[Woody's Workshop]

Love the Bertha. Absolute wonderful flyer. I guess that's why it's stayed around for so long.
It's loved by almost everyone.
Please, launch video and recovery if you can!
Thanks for sharing!