The Duplo cannons are composed of multiple physical pieces screwed together. Looking specifically on the cannon with locking ring and red button 17178c01 or 94886c01.
What is the minimum that need to be modeled?
Some motors, projectile launchers, and springs have been modeled down to each screw and separable part even if that has meant the creation of (sub)parts with u numbers. Obtaining subpart numbers and internal structure requires opening the assembly, possibly destroying its play-ability in the process.
Rubber insets are sometimes modeled only by their visible parts.
Can the firing button be modeled as a red surface or does it need to be a separate subpart?
How accurately does the internal structure (metal spring and projectile guides) need to be modeled?
Do the screws need to be modeled as separate parts?
What is the minimum that need to be modeled?
Some motors, projectile launchers, and springs have been modeled down to each screw and separable part even if that has meant the creation of (sub)parts with u numbers. Obtaining subpart numbers and internal structure requires opening the assembly, possibly destroying its play-ability in the process.
Rubber insets are sometimes modeled only by their visible parts.
Can the firing button be modeled as a red surface or does it need to be a separate subpart?
How accurately does the internal structure (metal spring and projectile guides) need to be modeled?
Do the screws need to be modeled as separate parts?