Since I’ve been unable to find a suitable “second cannon,”

I decided to design a fake one instead.

Haha, haha, haha!

It functions perfectly fine, and we’ll continue to refine and beautify it in the next stages.

Hardware list:

1. Cylinders, 36–40 mm in diameter, 70 mm long

2. O-rings, outer diameter 36 mm, wire diameter 3.5 mm, 2 pieces

3. Springs, outer diameter can be 20–16 mm, wire diameter 1.6 mm, 6–7 cm long, 6–7 pieces

4. Pins, 2 mm thick, 16 mm long, 2 pieces; plus 3 pieces 35 mm long (I used barbecue skewers for these)

5. Small springs, 0.5 × 5 × 15 mm

6. M3 × 10 screws, 5 pieces

7. M3 × 30 bolts, 4 pieces

8. M3 × 35 bolts, 2 pieces

9. M3 × 25 bolts, 2 pieces

10. Rubber washers, 3 mm thick, 30 mm in diameter

Special note: All the internal holes are designed quite tightly. If you can’t fit anything through, please enlarge the holes with a drill bit, or adjust the negative clearance in your slicing software.

The head and connecting rod must be brand new—absolutely no shortcuts here!

Installation video is available on Bilibili:

“Stiff Cannon! Recently released as free open-source!”