BOWLING BALL

DESIGN SUGGESTIONS


General

Items with an "R" beside them are rules, not just sugestions.

Design Options

There are three schools of thought on the design of bowling ball rockets.

All rockets shown are K Bowling Ball Lite entries.

Geoff Elder, LDRS in Texas Ball on a stick

Ball is exposed forming the nose cone and all or part of the transition to the main body. Various sized tubes have been used, minimum 54, as seen here, up to 7.5". Some designs have a conical section aft of the ball to reduce base drag.

  • Advantage- Lightest weight
  • Disadvantages- Least streamlined, unless tail cone is placed aft of the ball. A spherical nose is OK at low velocity. For launching, lug stand offs or a special tower are required.

Winners of BB lite have all been this design.

 

Mark Clark, LDRS in South Carolina

Photo from Yank

Exposed ball with cone

Ball is exposed only at its maximum diameter. A separate cone forms nose. A short cone is seen here but long and pointed one is used in some other designs.

  • Advantage- Lower drag if rocket is going to approach mach.
  • Disadvantages-Heavier than ball on stick. For launching, lug stand offs or a special tower are required.

Design has shown potential, but no winners.

 

Mark Clark, LDRS in California Ball totally enclosed

The ball is enclosed entirely in the airframe. It may be retained for recovery or have a separate parachute.

  • Advantage- most streamlined design
  • Disadvantages- heavier, no commercial available cones that are light enough.

Enclosed design works best with higher power rockets, M and above. Here with mach plus velocities the lower drag of a pointed cone will offset the weight penalty. All the Unlimited class rockets with O and P motors were enclosed.

 

The number one thing to improve performance is to reduce weight.

Pounds of airframe will hurt more than pounds of drag.

A safe structure is number one.


For Bowling Ball Lite

For Bowling Ball Heavy

 

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