3D Model Rocket
I was making a simple targeting system when I realized I need something for it to fire. I didn't end up using the following for that but I did think it was worth publishing.
Supplies
model rocket engine
filament
3D printer
slicer
Design the Body
Measure your rocket engine. I personally used an A3-4T Estes rocket motor. The dimensions of this are 45mm tall 13mm wide and long. I made another cylinder that was 17mm wide and long and 100 mm tall. Make the smaller a hole. arrange it into the bottom center of the bigger cylinder and grouped them. next I took a paraboloid and arranged it on the top to be the nose cone. Tip: If you change the sides on the paraboloid to 20 it will mesh perfectly with the cylinder. Group them and you are done with the body.
Design the Fins
Take a triangle. are it 2mm wide and keep it twenty for height and length. Take a cube and make it 2mm wide. Arrange it under the triangle so they line up. Group them and copy and paste 4 times. Arrange the 4 even distances apart around the body. Group the whole creation and you are almost done designing.
Design the Launch Ring
Take a cylinder and make it 7mm wide and long. Take another and make it 10mm wide and long. Take the smaller and make it a hole. center them and group them. Arrange the ring along the body between two of the fins. Make sure the hole does go into the body. This ring should fit around the average model rocket launch pad.
Rocket STL
I have attached the STL so you can check your work with mine.