NAR

Cluster Buster

 

 

 

Rules

 

 

 

 

Qualified Flights

All models and motor cluster combinations must comply with the NAR Safety Code:

- Total propellant weight cannot exceed 125g,

- Total motor impulse cannot exceed 320Ns

- Flight-ready models cannot exceed 1500g mass.

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Models exceeding these specifications must be inspected by an RSO with HPR experience before flight and once inspected, flown from the HPR pads.

All flights must be recovered successfully, as declared by the RSO

All flights must be stable, as declared by the RSO

All motors must light for the flight

Models must be returned so that the motors can be checked for successful ignition

You may fly your model a maximum of three times in order to achieve a qualified flight

 

You may fly up to 3 times and may use different models for each flight in this competition. The points and flights will be tracked for each model, and the flyer is awarded the best score of the qualified flights flown. Points are assigned on a per model basis only. Points will not be combined for all models flown. (Example: Your first flight qualifies and earns 11 points. You choose to fly a second time and it scores only 9 points; therefore, your best score for the competition is 11 points and not a combination of 20)

 

Scoring

Two motor cluster - five points

Each added motor above 2 – 2 points/ motor

(e.g.: a five motor BP cluster would score 11 points)

Composite motors – An additional point for each motor

(For example: a three motor AP cluster would score: 5 base points (two motor cluster) , add + 2 points for one additional motor, and an additional 3 AP points (1 point for each composite motor used), for a total of 10 points)

 

Staged clusters – add a bonus 2 points per flight for BP motors and 3 points per flight for staging AP motors.

(A BP motor powered rocket staging two motor to two motors (e.g.: the PSC Infinity) would score: 5 points for having at least two motors, + 4 points for the two additional motors, 2 points for staging for a total of 11 points in total.)

 

Note: the traditional one motor per stage configuration does not count as a staged cluster even though there are two motors used in the flight. However, if the booster (Lower Stage) is clustered, the sustainer (upper stage) may use a single motor.

Tips

 

 

 

 

Estes Ignitors tend to be good for up to 3 motors. If you’re planning on a larger cluster you may want to check with your favorite rocket supplies vendor (e.g. Apogee or Chris’s Rocket Supplies or others) to see if they carry a better alternative ignitor/starter. One of lesser known vendors MTG carries ignitors made specifically for BP motors (https://electricmatch.com/rocketry/see/23/6/bp-rocket-starters)

 

Clip whips are helpful for clusters exceeding two motors if using Estes ignitors.

 

Check your igniters with a multimeter for continuity before installing them. This reduces ( but not eliminates) the chances of using a broken igniter.

If using Estes type igniters, check that your igniter leads are not shorted ( touching one another , the clips or the blast deflector ) to get a clean, safe ignition of your motors.