I'd still bet that this will come in very fast even if it appears to rotate well in doing so - the overall 'flap area' versus the weight is the deal here.

Try to launch somewhere soft if you can - BT80 can crimp darned easily.


After you fly this, just think about how a way heavier 4" HPR job would be.....

I'm right there with you. The weight has me worried.
After decal and glitter paint (I just had to add it) we're at 292g.
The drag surface area is about 1/4 of the minimum I'd run with a parachute for this weight.
And the math for energy bleed for rotational speed/mass is above my pay grade.
We had a perfect evening yesterday with calm winds and clear skies for a launch but I decided to postpone until this storm passed to soften up the ground as much as possible- the body tube flexes just by holding it for assembly or paint. This might be a one & done after impact (well, 2 since I have extra tube and couplers for a repair).
I did make a new launch rod at 54" to hopefully keep it stable off the line so along with the muddy field it has about the best chance I can give it.
I think a 3 fin Mr. Twisty / Spinderella would be a better choice but I went with a "more correct" upscale for this trial- my templates include a 3 fin motor lock option.

Hopefully all goes well tomorrow.
I'll upload the launch video regardless.

Guys.
Hey guys.
GUYS!!!
.......
You're not gonna believe this:
https://youtube.com/shorts/hVRdcdeiQ84?feature=share

Attached Images

20230213_174719.jpg (1.30 MB, 17 views)

Second launch with Spinderalla tonight.
2 landings and body tube shows zero damage.
Yes I'm as surprised as you are. I was really beginning to question if the BT-80 was up for it.

Wind gusts were 2-3mph max both launches.
D12-3
Height felt around 200 feet +/-
1/4" launch rod at 54" (I might need to step up to a rail system if I go any further).
Descent speed doesn't feel any faster than Mr. Twisty, it's possibly even slower.

And after this success it brings me to another question.
Since the design seems to pass the requirements for HP certs, what's preventing me from making another mount for an F engine and using this rocket?
Of course if I was specifically building a rocket for HP I would go with thru-wall fins and use basswood, but is there an issue with this bird ripping apart under the increased speed?

That looked pretty good there even if you really look at how fast that came in from apogee.

From around 200ft or so at apogee it seemed to only take 5-6 seconds to land, that's right around a 35fps drop rate. That's about what to expect here.

If it lands on something harder at that speed it will likely crimp the BT80 if not also cause whichever flap-side hits first to crack. Yea, the old Rotaroc "first rotor" syndrome where you bend or break a hinge.

EVen if you made a 'moderate-ized' upscale and used basswood or such you'd have AT LEAST a 50fps drop rate. That might be a bit much for someone to sign off on.


You could make a midi version of this with the BMS 3" tubing (its not really LPG nor HPR tubing) and go with three flap-sides. Use bass or even thicker coated balsa for this and stick to reasonable F type motors. That might come in pretty well and the tube would likely make it.

I'll look into those tube options.
Not really sure where to go from here.
The missus' favorite rocket is Tazz, which is what started this snowball rolling. She doesn't like the concept of a 3 fin (and I know others feel the same on upscales).
I might have to do a pair, in 2 and 3 fin to keep her content.
I was going to do a test on a High Flier XL but all 3 of my "local" HL's rarely have them in stock so I may have to order one.

I borrowed my buddy's 3d printer so I might make my own nose cones for the next build(s).
I might also work on files for the motor/aileron lock setup in addition to the balsa templates I have.

Spinderella had an accident unrelated to launching.
One of the vertical fins was snapped in half after falling over.
After a wood glue repair and a launch it popped off on landing (its not an aileron side so it was just the shock from landing).
Super glue to the rescue and I'll launch again tomorrow if the weather holds.

This may be blasphemy, but deploy a clear plastic streamer to slow it down a bit...


Bill

__________________
It is well past time to Drill, Baby, Drill!

If your June, July, August and September was like this, you might just hate summer too...

Please unload your question before you ask it unless you have a concealed harry permit.

: countdown begin cr dup . 1- ?dup 0= until cr ." Launch!" cr ;

Give a man a rocket and he will fly for a day; teach him to build and he will spend the rest of his days sanding...

Try an E12-4

__________________
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 figured out how to deploy an actual Chute on a fishing swivel, not sure how much rotation I'd get from it but the geometry is sound.


Go ahead, dare me again.
Because I'll do it....


This is a test... Bill

Update:
5 launches and the body tube shows no sign of deformity.
?!?!?!?!?!
I know, right?!
Spinderella actually seems to slow down the more time she's in the air (after ejection charge).
Hard to judge because I've only launched with D12-3's and air time is pretty short but I'm comfortable enough with her now to try an E motor.
I'll record it and post of course.
Weather permitting I'll try for some time this week.

I still can't believe she survived thw first landing....