Funny springo-toy.

There are 3 necessary main parts: BurgerTop, BurgerBottom and BurgerSpring. The Spring interlocks (by rotation) with top and bottom. The layers of the spring should be manually separated after print. 
Also, there are optional parts, that can be put between top and bottom: BurgerPatty, BurgerMiddleBun and BurgerCheese. Last one features flexible corners that can be bent down for more realistic look. There is also a thicker version of it, if you afraid the corners could break.
And additionally there are many various fillings with clips to be attached to the spring: Tomato, Salad, Pickle, Onion and OnionRing.
 You can add optional parts and fillings in any amount and order you like!

All parts should be printed separately (preferably in different colors) and assembled after.

How to print:

All models are already in the right orientations. It's better to print everything with supports. 
Also, be careful when printing Cheese. There should be 1-2 layers above the corner grooves. Use thicker cheese version if you see no such layer(s) in your slicer. Also, it is best to use a concentric top pattern or a lot of perimeters for this model.

Enjoy your freshly made burger!

If you want to support me or get a Commercial license to sell physical prints, you can do it on my Patreon or Boosty.