How to make a Portal Gun

Step 6 Under belly

This forms the skeleton of the underside which later gets a skin. The shape is the bottom half (well more than half) of the previous part, so the bottom curve and the straights, cut from 6mm MDF and repeated three times. A hole was drilled through all three and a dowel measuring the rest of the length of the barrel (about 160mm) poked through and more hot glue.