Zoid (Level III Certification Project)

High Power (98mm M motors)

This is a scratch built rocket using high power construction methods.

Design Notes

Tripoli Level III Data Form for this project by clicking here . Last update 3/10/06.

My initial design calculations and sketch can be viewed here .

Here is a detailed description of the design (in progress) here . Last update 3/10/06.

The vehicle flight check list is here . Last update 3/10/06.

The vehicle (Zoid) will be built around 5.375" phenolic tubes which will be fiberglassed with an overall height of around 11'. There will be 3 sections, the motor/fin can assembly (about 4' long), a payload section with nosecone (3' long) and the parachute cannon (4' long). This will contain the 14' parabolic parachute which should give a decent rate of 3 m/s.

There will be redundant altimeters and an on board video camera and GPS tracking in the nose cone section of the payload. Dual deployment will be used for recovery. A 4' drogue will be released at apogee and the main will be deployed at 800'. This section will be capped with a 2' long plastic nose cone and payload bay.

The motor/fin can will be about 4.0' long. The 3 fins (fabrication depicted below) will be a rotated trapezoid (12"x11"x8"). They will be carbon fiber laminated to the motor tube between, and slotted into, the motor centering rings. This gives a CP about 6" ahead of the fins.

The motor selected for this certification is the AeroTech M1419 which delivers an average thrust of ~300 lb-s. This yields a thrust to weight ratio of almost 6:1.

The targeted weight for the rocket is 35 lb with a 15 lb motor. If met, this rocket will reach optimum performance at an altitude of over 10k' and a maximum velocity of just under Mach 1.

Component Fabrication

The fins are fabricated by laminating with epoxy, copper clad G-10 fiberglass between aircraft plywood sheets. Note that the G-10 was perforated to reduce weight and improve bonding between the 3 components

The fins blanks are epoxied together with West Systems slow cure epoxy and placed between two garbage bags with 60 pounds of weight to press the lamination together. After 3 to 4 hours, the lamination is turned over and allowed to cure for 20 more hours at 71 deg F. Note that a trash bag is used as release film (epoxy will not stick to this material).

Completed lamination. Note that the excess epoxy has been pressed out. The blank is light weight and EXTREMLY rigid.

Carbon fiber lamination is accomplished by wetting the blank and applying a layer of the mat. To compress the mat and remove excess epoxy a trash bag was filled with about 5 gallons of water and placed on top of the fin for curing.

Completed fin on the left and a blank on the right.

The image above shows The teflon bridles on the left and the centering rings and bulkheads which have been covered in carbon fiber.

This is the lamination setup for the carbon fiber wrap. The component is covered in West Systems epoxy and layed on a square sheets of the carbon fiber. A trash bag is used for release and the component is allowed to set up for 24 hours under weight (brick).

The major components.

The motor case.

Assembly

The motor tube with centering rings. Note that the fins are carbon fiber wraped and go through the body to the motor mount. The fillets were built with two layers of carbon fiber and West Systems Epoxy.

This is the "Rocket Rotisserie" used to lay up fiberglass and carbon fiber on the body tubes. This is the payload section being fiberglassed on the left and the parachute cannon on the right.

The major components completed.

The electronics bay will contain the dual altimeters and parachute deployment electronics (a G-Whiz 800 and a PerfectFlight 25K).

These are the basic GPS tracking components and the digital video camera which will ride in the payload section. The GPS receiver module sends coordinants via RS-232 to a 900Mhz spread spectrum digital transmitter. The companion receiver is connected to a laptop for tracking and altitude telemetry. This system easily fits in the payload section and nosecone.

This is the tracking display. Note that there is Lat., Lon., Alt., ground speed ...

Simulations

The CP calculation.

Here is the predicted flight profile.

Flights

Black Rock, NV. Level III Certification Attempt

Flight day XPRS at Black Rock, NV. September '05. Loaded with an M1419.

On pad A and armed.

Off the Pad.

Through the sound barrier toward 11k ft.

Partial recovery, main chute tangeled and we broke a few body tubes ... (went to 11.1k ft.). Repairs were modest.

Click here for a slide show of Zoid's chute deployment problem (1.5Mb)! RUN SLIDE SHOW

My analysis and re-design notes ... click here .