Quantcast

Halcyon. 2nd quarter build challenge. Tractor motor helicopter

The Rocketry Forum

Help Support The Rocketry Forum:

BABAR

Builds Rockets for NASA
TRF Lifetime Supporter
TRF Supporter
Joined
Aug 27, 2011
Messages
7,723
Reaction score
2,641
Okay, still in thought stage, but will start here.
Challenge is a tractor build.
I really enjoy helicopters and hope to eventually get an L1 cert on a heli. Need to work out a folding rotor design, this will give me a chance to play around a bit.
Thinking three rotors, each folded in half, with three D12s up front.
 

Daddyisabar

Oddrocs Rule!
TRF Supporter
Joined
Jan 23, 2009
Messages
4,696
Reaction score
277
Location
Littleton Colorado
HaHa...I first read that has a Tractor with helicopter blades...

I guess having Classic Tractor Fever doesn't cross with model rocketry well...
Use some tractor motors to build a tractor pulling the sled in a sky high tractor pull! Have a moving weight as the rocket lifted off! You would be the top dog in the mid west with that sort of rocket.
 

BABAR

Builds Rockets for NASA
TRF Lifetime Supporter
TRF Supporter
Joined
Aug 27, 2011
Messages
7,723
Reaction score
2,641
IMG_5265.jpgIMG_5266.jpgIMG_5267.jpgIMG_5269.jpg

okay, starting to take shape.

Given size of this and the forward motors, , my usual 4 rotor configuration for rotor retention on ascent won't work, so going with three rotors at this point.

The forward motor configuration calls for a tractor design, a la "tapeworm" configuration at least to start with,

https://www.rocketryforum.com/showt...n-this-Tapeworm-Model-Rocket&highlight=scolex

(yup, stealing shamelessly.)

Will be going with 3 D12s. Estes Engine chart https://www2.estesrockets.com/pdf/Estes_Engine_Chart.pdf puts max lift off for D12 at 396 grams (this rocket ain't gonna sim)
So figuring about 1200 grams is my MAX, I would prefer to stay well under that.

the three engines themselves take up 100 grams.

Weight of each of these three skeletal frames is 70 grams, I will be using regular printer paper to "paper" the outsides, not sure how much that will be. ( I have monokote, don't have a clue how to use it, and not sure frame would hold anyway.)
Currently using 3/16 dowels, 48 inches long, two per rotor. Seems a bit weak now that I "feel" the weight, I may add a central 1/4" dowel to each one.

I would LIKE to add an extension folding fin on each one. The current rotors are just over 4" wide (4" balsa struts, with 3/16" dowel on each side, plus paper not added yet, so probably will end up 4.5")
The extension fins would be about 3" wide, also probably about 48" long.

The fins are 12x6, although again about 4" is integrated into the rotor, so effectively about 8 x 6. Looks like about the right amount of fin area, especially as with engines forward this should have a very far forward CG.

If I cant the motors about 10 degrees, I can actually use the forward motors as the rotor stops at deployment. I like the efficiency.

Haven't come up with a definite method of rotor retention on ascent. Can't use what I did on Twirly https://www.rocketryforum.com/showt...mall-Field-Helicopter-Rocket&highlight=twirly or Whopper Flopper chopper https://www.rocketryforum.com/showthread.php?28887-Build-Thread-for-Whopper-Flopper-Chopper

will need some sort of burn string or burn band
 

Latest posts

Top