AutoInjector Prototype

A lose design of the spring mechanism inside an autoinjector, used to accurately administer syringe medicine


Creative Commons Attribution Share Alike

Commercial use is allowed, you must attribute the creator, you may remix this work and the remixed work should be made available under this license.

Learn more or download attribution tags



I attempted to model the spring/trigger mechanism that powers devices like the Autoject EI. They allow for the easy administration of medicine like insulin or epinephrine. This includes many pieces.

*injector body - encases all components
*plunger and firing button casing (blue in picture) - houses the springs and plunger rod, hold trigger button
*plunger rod - pushes the syringe to inject medicine; powered by compression of 2 springs
*spring holder (top and bottom)-balance the set of springs on the plunger rod
*indicator (yellow in picture) - barrier between plunger rod and syringe base; aids in measurement of needle depth
This turned out to be way beyond my CAD abilities, so hopefully someone can pick up where I left off and make this product available for those that cannot afford the commercial equivalent.

Materials and methods

3 springs
1 clear window -- optional



Issues are used to track todos, bugs or requests. To get started, you could create an issue.


Bf80d14a7a0bfb961673eac01321b195?default=blank&size=40kjskls226 added this to the future makes collection ago
266c71a44e7acff150184cc085279aac?default=blank&size=40njmcgrat published this design ago