Design

Home Construction Design Members Launch Report Videos Sponsors

 

 

 

Current Design Issues

Very few items in the design have been finalized. This page represents some of the first round design ideas being kicked around.

 

Overview

bullet

Overall length of 30 feet long with an 18.5" diameter airframe.

bullet

Powered by three 6" "P" motors, totaling 163,800 Newton-Seconds.

bullet

Airframe will consist of three parts, the nose cone, upper payload section, and the lower booster section.

bullet

Recovery will be dual deploy, with a 27 foot drogue chute, then deploying a 47 foot main parachute.

 

Motor Mount

bullet  The engine mount will be an "open frame" design. This design will utilize centering rings only, and no motor tubes. This is need to prevent heat buildup within the motor tubes. It will also allow for thermal expansion of the motors during flight.
bullet Currently five centering rings will be used along the length of the motors, and will be made from 3/4" birch plywood.
bullet The structure of the motor mount will be maintained by locking the rings in place with both the fins and several lengths of all thread.
bulletThere will be a total of 18 pieces of 5/16" all-thread running the length of the motor.  
bulletThere will be be four pieces of all-thread used for each motor. Two pieces will be used for motor strength/retention only. The other two pieces will be shared between motor strength/retention and fin anchoring. Two additional pieces of all thread will be placed at the body tube to fin tab junction (see fin description for additional details).

 

Fins

bulletUPDATED 11/28/03
bulletCurrent fin design calls for the fins to be cut from three pieces of 1/4" birch plywood.  A full size center section, along with two backing plates.
bulletOnce the core material is created, the fins will be built-up using "Blue Foam" to give them the scale shape, and then covered in three layers of carbon fiber.
bulletFor a complete description showing each layer of the fins check out the fin layer page.
bulletFour pieces of all-thread will run the length of the fin tab. Two pieces will retain the bottom of the tab, and also be shared for motor retention. Two other pieces will be placed on either side of the fin at the intersection of the body tube.

 

Main Airframe

bullet Fiberglass pipe was originally discarded as the main airframe material due to it's high cost. After doing some preliminary stress analysis fiberglass pipe is back in the running.  This material is being considered because of the following criteria:
  1.  High Strength
  2. Strong recommendation from Neil McGilvray
  3. Published design data, allowing accurate calculations rather than guess.
  4. Simpler construction and finishing.
bullet 18 inch diameter "Sonotube" laid up with three layers of composite (carbon fiber, Kevlar & glass) has been ruled out. 

 

Nose Cone

bulletThe nose cone will be built starting with an all fiberglass section for the tip. This nose cone is being manufactured and donated to the project by Performance Rocketry.
bulletThe central core of the nose will be made from 7.5" PML tube covered in two layers of 10.0 oz glass.
bulletCentering rings will be cut from 1/2" birch plywood.
bullet1/4" plywood ribs will run the length of the nose cone.
bulletThe ribs & rings will then be sheeted with fiberglass strips cut from the airframe material for the first 2/3 of the nose and PML 11.41" tube strips for the forward most 1/3.
bulletA final layer (sealing layer) of glass will then be applied to the entire nose.
bulletThe nose cone shoulder will be made in a same manner as the coupler tubes.
NOSE.jpg (93124 bytes)

Click HERE for 3D Solids modeling of the nose cone

 

Coupler Design

bulletSections of the airframe be cut to form the couplers.
bulletTwo tube sections will be used for each coupler, with airframe tube as the outer tube, and glassed 11.41" PML tube for the inner tube.
bullet1/2" Rib structure will be built between the two tubes.
bulletFour pieces of 1/4" all thread will run the length of each coupler.

 

Structural Design

bulletSome initial requirements for the strength of the airframe. These requirements, and the way they were determined are detailed here.

 

Retention Plates

bulletThe forward plate will be the main thrust plate and all thrust should be centered on that. The four bolt holes per motor will transfer the thrust from the plate, down the sides of the rocket to each of the centering rings.
bulletClick for AutoCAD Drawing

 

bulletThe aft plate will provide a solid surface for motor retention.
bulletClick for AutoCAD Drawing

 

 

For problems or questions regarding this web contact WebMaster@BlackBrant2.com
This page looks best when viewed on my computer and was last updated on 01/24/09
THE BLACK BRANT PROJECT on the verge of insanity