Square Dance anyone?

[BABAR]

Well, been too long since I built something.

since I have over a decade building square rockets, I was thinking maybe I could come up with something that, to my knowledge, doesn’t exist in the NewWay stable (apologies Rick @Bluegrass Rocket if I am wrong.) A square helicopter rocket that uses their unique tubing.

I don’t have enough of the square tubing that I bought too many years back, from website says 1.1 inch diameter, so I am making my own out of cardboard. The cuts are one inch exactly, when folded into a square comes in at about 1 and 3/16”.

this will just fit a BT-50 inside. I built something like this with Randy’s tubing a while back, it came in a bit heavy so I am thinking 24mm. I can always adapt down.

 

[neil_w]

FYI it's Rick, not Randy.

 

[lakeroadster]

FYI it's Rick, not Randy.

Or maybe it's Huey?

But don't you try to fight it, an idea whose time has come
Don't tell me that I'm crazy
Don't tell me I'm nowhere
Take it from me
It's Hip to be square

 

[BABAR]

FYI it's Rick, not Randy.

fixed, tx

 

[Funkworks]

We can post music videos? Good thing because the only advice I have is from a music video.

"Whirl, whirl, twist and twirl,
jump all round like a flyin' squirrel.
Now don't you cuss and don't you swear,
just come right out and form a square."

 

[BABAR]

Well shoot, I guess it would help if I specified what was unique, I fixed it in the initial post. To my knowledge, NewWay doesn’t have a helicopter rocket. (not sure if they have any gliders, either, but I will leave that to @Rktman to fix!)

anyway, I think if have a fairly unique design which should be very simple and very reliable. I have built a three rotor version, but I think this would lend itself quite well to the the NewWay square tubing.


Teases for the build, this uses no elastic, no burn threads or burn strings. It will require a custom nose cone (I make mine with posterboard, I don’t know how difficult it would be to make a plastic one, but other than being a specific size it’s not that complicated.) It also requires no baffle or wadding, and it comes down as a single piece.

 

[Pepe Le Pew]

Subscribed with popcorn!

 

[BABAR]

Rotor fins made.

the left with the angled cut at the base and the right with the cut marked but not cut yet. This angle will set the pitch of the rotor fins when attached.

I am sort of the anti- @lakeroadster , i just guess the angle, I think it is about 5-10 degrees.

 

[BABAR]

Cardboard tube wrapped with duct tape, with a BT-50 inside.

@kuririn , you’ve done some NewWay rockets, will their tubing fit a BT-50 okay?

 

[BABAR]

Angle mark on tail end of tube

 

[BABAR]

All four cuts in tube.

 

[kuririn]

@kuririn , you’ve done some NewWay rockets, will their tubing fit a BT-50 okay?

Yep, with room to spare.

 

[BABAR]

1x2” tape for tape hinges.

for these, I like the Gorilla brand tape. I use the cheap colored tapes for decoration and sometimes I will use it for hinges, but I can strengthen that by sewing in with dental floss. I think this is gonna be low stress, and awkward to access.

 

[BABAR]

Tape on inside of the tube, sticky side out

Rotor fin in place lined up with left edge of body

Tape wrapped around.

Hinge open and carefully positioned, with Tape “pinched” between end of rotor fin and body. You can just see a thin strip of gray

Notice the slight pitch angle.

Second tape applied. This will be the “inside” when folded for launch.


Side view in folded position.

 

[BABAR]

 

[lakeroadster]

Rotor fins made.

the left with the angled cut at the base and the right with the cut marked but not cut yet. This angle will set the pitch of the rotor fins when attached.

I am sort of the anti- @lakeroadster , i just guess the angle, I think it is about 5-10 degrees.View attachment 518199

Any similarity to the design.... vs the finished product... is purely coincidental.

 

[BABAR]

Rotor stops.

 

[BABAR]

Upside down but open

 

[Rktman]

What material are the rotor stops made of?

 

[BABAR]

What material are the rotor stops made of?

Red ribbon (like you use for birthday gifts.)

Nice thing is it folds up nicely inside the rotors for launch.

Given cost of balsa going up, I think the rotor fins could easily be done with fiberboard (picture matting at Hobby Lobby would work).

 

[BABAR]

Nose cone parts.

outer shell is poster board (cheap stuff, $0.47 per sheet), covered with Mylar tape.

BT50 tubing adaptor has cuts to fit inside the shell.

not seen but inside the tubing is a cardboard bulkhead with a small piece of aluminum can on the inside to protect from ejection blast.

I am between houses (living in new house without having moved much of our stuff) so I don‘t have any snap swivels, so for now a couple of Kevlar loops will connect.

only concern I have is that the spinning helicopter will cause the shock cord to wind up.

 

[lakeroadster]

Very cool. The nose cone reminds me of those old school square flashbulbs we used to use on Kodak Instamatic cameras...

 

[BABAR]

The green things are soda straws and the leading edges of what when deployed are the tips of the rotor fins. These are frangible

Definition of frangible​

: readily or easily broken

not sure how fast this will be spinning when it comes down. It will also hit tail first and tip over. So the leading edge tips of the rotors may impact hard, not good on balsa. The soda straws will bend and take up the kinetic energy. If they break, much easier to replace than to repair the balsa.

pic with nose cone on. Really struggled to size the nose cone, it’s too big, but tried smaller and was too tight.

if Rick at @Bluegrass Rocket picks this up, suspect can size this much better. This is just a prototype.

 

[BABAR]

the masking tape will come off, just holding it in place while glue dries attaching shell to adapter.

 

[Rktman]

Nose cone parts.

outer shell is poster board (cheap stuff, $0.47 per sheet), covered with Mylar tape.

BT50 tubing adaptor has cuts to fit inside the shell.

not seen but inside the tubing is a cardboard bulkhead with a small piece of aluminum can on the inside to protect from ejection blast.

I am between houses (living in new house without having moved much of our stuff) so I don‘t have any snap swivels, so for now a couple of Kevlar loops will connect.

only concern I have is that the spinning helicopter will cause the shock cord to wind up.View attachment 518828

Very cool design. So the nose cone keeps the rotors locked in place until released by the ejection charge? So there shouldn't be any problem with the shock cord winding up if the nose cone will just be freely hanging below the rocket, yes?

 

[Rktman]

The green things are soda straws and the leading edges of what when deployed are the tips of the rotor fins. These are frangible

Definition of frangible​

: readily or easily broken

not sure how fast this will be spinning when it comes down. It will also hit tail first and tip over. So the leading edge tips of the rotors may impact hard, not good on balsa. The soda straws will bend and take up the kinetic energy. If they break, much easier to replace than to repair the balsa.

pic with nose cone on. Really struggled to size the nose cone, it’s too big, but tried smaller and was too tight.

if Rick at @Bluegrass Rocket picks this up, suspect can size this much better. This is just a prototype.View attachment 518853

Just saw your post (#23). Seems I mistakenly thought the rocket would come down nose first. (Or did I misunderstand again and it does)?

 

[BABAR]

two small launch lugs, since these are on rotors will cause some drag when spinning. Although with this design the lugs will be very near hub, so even when spinning not nearly the drag ( nearly all if not all previous designs had the hinges forward, so the launch lugs were near the rotor tips when deployed.)

 

[BABAR]

Just saw your post (#23). Seems I mistakenly thought the rocket would come down nose first. (Or did I misunderstand again and it does)?

you are correct, this comes down nose first, the hinges at the back will place the straws at the tips of the rotors When deployed.

I sort of got the idea from a mod that @neil_w did on his helicopter kit and the Estes Flip Flier.

the Flip Flyer would be a much better and simpler rocket if they just extended the rotors the length of the body tube, did a custom nose cone that incorporated the yellow plastic rotor retainer.

blow the cone on a short shock cord (cone is lightweight), rotors deploy and are longer so more surface area and therefore more hang time.

your next question may be, what opens the rotors? At least my theory is, one the nose cone on the Square Dance blows, the rocket will start a ballistic fall, the air stream SHOULD drag the rotor tips away from the nose. So no elastic needed.

 

[Rktman]

your next question may be, what opens the rotors? At least my theory is, one the nose cone on the Square Dance blows, the rocket will start a ballistic fall, the air stream SHOULD drag the rotor tips away from the nose. So no elastic needed.

Seems logical, especially if the CG is biased toward the front end of the rocket and drag from the nose cone doesn't keep the rocket horizontal. Maybe have the nose cone come down separately on its own streamer?

 

[neil_w]

your next question may be, what opens the rotors? At least my theory is, one the nose cone on the Square Dance blows, the rocket will start a ballistic fall, the air stream SHOULD drag the rotor tips away from the nose. So no elastic needed.

Will be interested to see how reliably that works in practice. Take good video.