Project Nike Dart

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Nike Dart is a custom designed, scratch built rocket that is fairly small but sports a 54 mm motor mount. It is named after the Nike style fins on the ACME™ injection molded fin canister. The fin canister fits perfectly around the 54mm motor tube but also fits inside of the 2.6 inch body tube so that only the fins protrude from the body tube. An Aero Pack screw-on motor retainer completes the motor section of this rocket. The Missile Works altimeter is mounted inside the PML "Intelli-cone" nose cone but provision is made for the static ports to be about 1 caliper below the nose cone shoulder to prevent problems with air turbulence off the nose.

The ejection charge holder (ECH) for this rocket is unique in that it can be prepared and loaded into the front end of the rocket. It screws into the bulk head that separates the altimeter bay from the parachute compartment. This allows the ECH to be added after the recovery harness and parachute are packed and loaded. The ECH has room to two igniters (for redundancy) and the igniter wires come out the front of the ECH for easy and direct connection to the altimeter. This rocket uses 1.5 grams of black powder for ejection.

Click here to view launch photos of Nike Dart.

CAD drawing software information.

View Nike Dart Design Drawing

View Nike Dart Paint Scheme plans

Nike Dart Specifications

Length:	4 feet, 6 inches
Diameter:	2.6 inches
Weight:	8.4 pounds with K185 motor
Motor:	54mm mount accommodates up to K550 motor (Aerotech 1706 NS case.)
Altimeters:	Missile Works RRC²
Locator:	Walston radio transmitter
Payload:	none
Parachute:	Rocketman R7
Built:	Spring 2002
First Flight:	July 20, 2002 on I161 motor at Bothers Oregon launch site
Construction:	Body tube: flexible phenolic + 2 layers of 6 oz fiberglass Fins: Acme fin can for 54mm motors Nose cone: plastic PML "Intelli-cone"

Stability Analysis

Results for a K185 motor.

Simulation Results

Motor: K185W

Maximum altitude: 11396 feet

Maximum velocity: 615 MPH

Maximum acceleration: 8.4 g's

Time to burnout: 7.7 sec.

Time to apogee: 26.3 sec.

Launch guide length: 60 in.

Velocity at launch guide departure: 32 MPH

The launch guide was cleared at: 0.30 sec

Liftoff weight: 8.4 lbs

Ejection Charge Holder

The ejection charge holder (ECH) for Nike Dart is built from four small brass fittings and a short section of thin wall brass tubing. These parts are shown in the next two pictures.

Part "B" is a 3/4" to 1/2" brass bushing and part "A" is a 3/4" brass nut. These two parts are permanently mounted in the bulkhead in the rocket.

Part "C" is the charge holder itself. It is made from a 1.75" long section of 7/16" brass tubing that has been soldered into a 1/2" to 1/4" brass coupler. The tubing is small enough to pass through the bushing "B". The coupler "C" screws into the bushing "B" when the holder is installed into the rocket.

The back side of coupler "C" has a short extension with threads on it that allow a small cap "D" to be screwed in place. A small 1/8" diameter hole is drilled into the cap to allow the igniter leads to pass through. The inside of that small extension can be filled with modeling clay prior to installing the cap in order to seal the igniter leads. This prevents any ejection charge gases from getting back into the altimeter bay. The next two photos below show the cap installed on the coupler extension. The small hole in the cap for the igniter leads can also be seen.

ECH - rear view showing hole in cap piece

Bushing and nut for ejection charge holder

This photo is another view of the bushing and the nut that mount into the bulkhead in the rocket. These are parts "A" and "B" mentioned above. (Note, you can always click on any photo to see a larger view of it.)

The next two photos show a fully assembled ejection charge holder.

ECH ready to go into rocket. Igniter leads coming out the back.

The ejection charge holder itself is assembled by first installing two Daveyfire igniters with their leads extending out the back side of the unit. Modeling clay is then pushed into the back side extension and then the small cap is screwed in place. Next the black powder (1.5 grams) is added into the front end of the brass tubing. Some fire proof wadding is then pushed into the tube to fill the remaining space and hold the black powder snuggly in place. At that point some masking tape is used to seal the front end of the tubing. The unit is then ready to install into the rocket and the igniter leads can be connected to the altimeter.

Altimeter Bay

View of altimeter static port and nose cone retention screw

This shows the joint between the nose cone and the body tube. One of the nose cone retention screws has been partially removed. An altimeter static port hole can also be seen. It is well back from the nose cone so that it will sense the correct air pressure.

Here the nose cone has been removed. The yellow igniter wires connect the altimeter to the igniters in the ejection charge holder. The ejection charge holder can not be seen here, it is further inside the front end of the body tube.

This view is looking down on the nose cone and the body tube. The altimeter bay has been partially removed from the nose cone and the altimeter itself has been partially removed from the altimeter bay tube.

Here the altimeter has been completely removed. It is still connected to the igniter leads. The altimeter is a Missile Works RRC². It is set for redundant apogee deployment mode so that two independent igniters can be used.

Motor Section

This is the motor section. The front end of it is the coupler that fits into the body tube. The fins are part of the ACME™ injection molded fin canister. The U-bolt on top is for attachment of the recovery harness. Two small black rail guides can also be seen.

This shows a rail guide along with a 6-32 tee nut and a 6-32x1/2" bolt.

The rail guides are anchored by a tee nut that is placed inside the body tube. Here the unit is assembled, but of course the body tube itself is omitted in this photo. If the "teeth" on the tee nut are too long they will poke through the body tube. To prevent that, just trim them a bit shorter with a pair of diagonal cutters.

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