c9kinetic Projector

I am currently trying to master the use of 3d compliant designs and, more specifically, springs that I can use in more complex designs of 3d printable machines in the future.   I have seen many very interesting and effective compliant mechanisms, but at the top of the list for me is the BYU One-Piece Compliant Mechanism Disk Launcher.  When I first saw that, I was so impressed.   I thought I needed to understand how to make energy storage and springs like that.  And, honestly, toy guns are just fun, so here is what I came up with…

Now, I know not everyone likes the idea of printing guns of any kind, but some of my fondest childhood memories are of playing with toy guns with my then best friend, Simon.  We played for hours, days and in fact years and exercised our imaginations with great delight.  So, it is no wonder today that a toy gun still brings me some enjoyment.  This c9kinetic projector is something I would have loved to play with back then (and I still love it now).  

The design is simple and requires only a frame/housing to provide structure, a spring to store and release energy, a trigger to hold and release the spring and a barrel to hold and guide a projectile.  For comfort, I have added a folding grip and two other small components that hold the two sides of the frame/housing together.  

The c9kinetic Projector is a unique and compact toy that demonstrates the principles of compliant spring designs. It is capable of launching small plastic projectiles using the elastic energy stored in a specially designed compliant spring. The mechanism is powered by a 1-piece, 2-stage, 2-layer spring, which allows for a compact and less flat design inspired by the well-known BYU “One-Piece Compliant Mechanism Disk Launcher”.

This toy is entirely 3D printed and is a snap-together assembly—no hardware, fasteners, or adhesives are needed.

The spring is “charged” (compressed) by rotating the barrel 90 degrees, allowing you to load a small projectile into the back of the barrel. The barrel stays in place thanks to a compliant locking system on top of the c9kinetic, which can be released by gently pulling back on the lock with your thumb. When the barrel is rotated back down, the system automatically re-locks.

Additionally, the grip is foldable, allowing you to reduce the overall size of the c9kinetic Projector for convenient storage.

Print Settings

Functional designs (such as this one) generally require more strength than non-functional designs and more strength than the typical default slicer settings provide, so please review your slicer settings carefully.

This product was designed for a 0.4mm nozzle, a 0.2mm layer height. For best results I suggest the following:

• Line Width = 0.4mm
• Wall Count = 4 (1.6mm)
• Top and Bottom Layer Count = 5
• Detect Thin Walls = ON
• Wall Generator = Arachne
• Material & Infill =
  • 301 Spring = PETG 100% infill
  • 9×20 projectiles = PLA 100% infill
  • All other components = PLA 40% (Cubic) infill
• Support = No, all required support is incorporated into the design.
• Print orientation = As per the STL/3MF files and the included image

Assembly Notes

After printing, be sure to remove the print support, as illustrated in the following illustration.

Assembly is described in the following 2 images.