This model Rocket Fin Jig can be used to secure both 3 and 4 Fin model rockets. I use it to arcuately position the Fine of the Estes rockets. There are other Fin jigs available but the one supports both 3 fin and 4 fin models.
Created using Tinkercad.
Th clamps in the image are located on Thingavers: 90mm Hobby Clamp. These were printed at 66% of the original size.
The author marked this model as their own original creation.