Thridget60
1.6x Upscale Midget with three motors per stage (3x13mm cluster)

Midget Family


Thridgets


This 1.6x upscale Midget is a two-stage cluster with three motors in each stage.  Each booster motor has its own individual fin section which allows each motor to separate independently from the others.

A key to success in staging clusters is dealing with uneven booster burn times.  If one burns out before the others, and causes the entire booster to separate, the chances of getting all the sustainer motors lit is slim. 

With each booster motor having its own booster section on the Thridget60, the chances of getting each upper stage motor lit are greatly improved.

In the pic at left: The reflection of the checkered fin and blue booster fin can be seen in the chrome trimkote on the left upper stage fin.


Here's a shot of the Thridget60 on the pad for its only flight so far.

I shortened the chord on the booster fins to accomodate the 1.75" long booster motors.  The alternatives were either gluing extensions onto the booster motors (for tape-together staging) or using gap staging which would have added several complications.


Below is a pic of the fins.  A rear thrust ring in each one ensures it separates with its motor at staging.

The aft end of the sustainer shows the motor tubes spaced evenly between the fins and the launch lug tucked into the fin root.



A decal recently added gives it a little more character.

Doug's Rockets Homepage

8-29-2010