Double-decker bus (no supports, no hardware needed)

This is a **double-decker bus** a friend wanted, featuring **3rd generation optimized printing springs**, **no hardware required**, and simple installation!! It was originally intended to have a hollowed-out windshield and windows to show the interior, but after a rough estimate, it was found that printing time and filament would increase by 1-2 times, and the door opening/closing might not be possible at this size, and the strength would be greatly reduced, so it was canceled!! If any friends still want it, please leave a comment, and if there are many requests, I'll try to make one. (Small size approx. LWH: 126*45.6*54.4mm)

Notes: To reduce printing time and filament, the small **body** has an infill density of 7% (overhang approx. 12mm), and the large size is 6% (overhang approx. 15mm). If you are unsure whether it can be printed, please increase the **infill density**, otherwise the roof **may collapse**. I have tested it and it prints normally!!

The GIF below is the assembly diagram:

1. The rearview mirrors are left and right, with the protrusion facing outwards. After installation, they are flush with the body!! Note: Do not press crookedly during installation, or it will break!!

2. **Tilt the wheel** into one side of the axle buckle, then use your thumb to press on the **red circle**, and your forefinger to press on the **side of the wheel** with force to push it in (using leverage). The other side's wheel is installed the same way (see the GIF)!!

Note: 1. Both PLA and PETG can be printed. It's best to understand the characteristics of these two materials before printing to avoid printing failures!! For example, PLA can become brittle if left for a long time or at low temperatures, while PETG has good toughness. Please choose the filament that suits you!!

        2. If it's for younger children, and the parts are small and easy to disassemble, it's better to glue them firmly with 502 or other adhesives to prevent them from being swallowed!!

        3. If there are no special requirements, please do not use your own advanced process settings for printing~ to avoid printing failures!!

If your printd part has local spaghetti, or the filament doesn't stick to the build plate, please recall if you touched that area (hands secrete sweat and oil, touching it has a very high chance of causing spaghetti)  or if the build plate is dirty. The solution is to search online for how to clean a 3D print plate!! If other problems occur, please describe it in the comments section and add pictures, so it's easier for us to solve it~  Otherwise, I can't imagine the situation = =!!