Simple but interesting some mathematical stuff.
Explain in word can take to much time, so I attached graphic which explain basic.

For more information i propose look a topic conic section.

If you have any comments feel free to contact me.

Print instructions

Print without support in origin orientation and should fit well.

Print parameters:

• 0.4 mm noozle
• 0.2 mm layer heigt
• 20% infil