Previously, the team selected the components and made a test PCB for the inside handle. Now it’s time wire it up; attach the motor, trigger, and hot end; and program it using AVR studio to control those things and see how the glue gun works. Once they put the motor and hot end on top they’ll have their first working prototype! Ben goes into Autodesk Fusion 360 to design a few features such as a spring to push back the trigger. He’s adjusted the design to have a quarter inch holes in the trigger. What he hopes to accomplish is to build up the extruder part of this so they can actually test the whole thing. They have all the controls to drive the gun. The extruder part might not be quite so refined. He creates some symmetrical mounting points for driving a size four screw on the inside. He starts printing one half of the trigger so he can get to work on designing the other half. Ben is still working on the extruder design. It has a lot of mass to hold the silicon entry point of the nozzle. He hasn’t started on the nozzle holding yet but he shows where it is going to go. The bearing imported from McMaster Carr, a feature of Fusion 360. He adds a cap to go over the gear and shaft. The glue gun will go right down the middle. Next, it’s time to figure out how to attach the part (using a foam mock up) to the main handle. What matters is the piece’s relation to the hot end as it shows us how far the nozzle’s actually going to be. If you put the motor too far the back the gun is not going to be too short. When he has an idea of how things are going to be put into place he 3D prints the parts. Ben screws the new handle pieces together and then tests the spring. The main things that are going to go up are the motor control, the triac control for the hot end, and then the temperature control. There might be more things in the final product, such as a push button or an LED indicator, but what they have is enough for testing purposes. They test the