Customized version of https://www.thingiverse.com/thing:695599

Created with Customizer! https://www.thingiverse.com/apps/customizer/run?thing_id=695599

For this model
https://www.apogeerockets.com/Model-Rocket-Kits/Skill-Level-3-Model-Rocket-Kits/Amarok

The glue clearance space can also be used as fixture when gluing the launch lugs.

Using the following options:

tube_diameter = 66
fin_width = 3.4
fin_number = 3
jig_height = 30
jig_fin_width = 30
wall_thickness = 4
glue_clearance = 5.5
$fn = 150