Aliens M41A Pulse Rifle - The Grenade Launcher

In the original Pulse Rifle the underbarrel grenade launcher is a shortened, repurposed pump action shotgun. To simplify this project, and because airsoft pump action shotguns are surprisingly expensive, we going to use the Launcher from the Thingiverse 3d Model as a substitute.

I adjusted the Pulse Rifle 3d Model to the correct scale using measurements from the Airsoft Tommy Gun and cut the launcher away from the rest of the rifle. A little clean up work later and we have the launcher as a single solid object.

To fit the 350mm long Launcher into my 150mm tall MakerBot Replicator it has to be cut into 3 parts using SketchUp. I also added attachment pegs to each section to simplify reassembly.

Front and Rear sections of the launcher are easy to print, but the center section will need support material. MakerBot Desktop’s supports are a pain in the ass, so instead I'll use Meshmixer. Meshmixer lets you create minimal supports only where you needed them. They work great, are easy to remove, and are much more efficient.

Estimated Print Time with Makerbot supports, 11 hours.  

Estimated Print Time with Meshmixer supports, 6 hours. 

The finished launcher looks great.  A little modeling putty and some sanding will have it ready for paint in no time. Unfortunately, something is off. Look closely at the small reference model I printed on my Form 1+.

The Thomson's barrel is about 30mm too short. Damn.  

After rechecking my measurements, I have to conclude the original Pulse Rifle didn't use the stock Thomson barrel.  I'll have to look into ways to fix this.