Space Engineers Automatic Rifle

For those not familiar with it, Space Engineers is a sandbox construction/survival game set in the near future, both in space and on planets. It is more associated with building space ships and mining then carrying around a gun shooting things. Nether the less I quite like the design of the automatic rifle and really wanted to make one.

When planing out this project I wanted three parts to move/light up: the green LED and dial on the left side and the trigger. The LED would require some batteries which I planned to hide in the magazine. For materials most of the gun would be made from various sizes of foam PVC, styrene plastic, screws and 3d printed parts.

This project has a lot of curved and beveled edges for which I used 2 different methods. Rather than repeating them each time they were used below, I will describe them here and then refer to them as method 1 or 2.

  1. Method 1 involves filling a small spa20170723_173241.jpgce between an L shaped cross section (or any gap between other bevels) with filler.  This is then filed and sanded flush to both edges to create an angled bevel. See right image.
  2. Method 2 is used to create bevels when the space is larger or wider and curves. This involves first creating a paper template of the shape of the bevel or curve. This is then used to cut out guides. These are evenly spaced and the gaps filled with scrap material, followed then a layer of filler. The filled areas we filed and sanded flush to the guides (see below image).  It is important to make sure everything is sanded smooth using a high grit of sand paper. Otherwise the guides and any bumps will show through after painting.











I began the project with the trigger and grip, a tag was left on the front and top to slot into the main body. Originally the main part was one piece of PVC foam. This was a problem when I came to cut a channel for the trigger to sit in. This was redone in two halves, the channel cut out and then glued together. The trigger and a spring were inserted. I then built up the shape using styrene plastic sheet and more foam PVC.

The grips were cut from foam PVC and using the blue print, lines were traced onto them. These were shaped using files and smoothed using various grits of sandpaper. The bevels were created by using method 1.



Next up was the rear stock. This is basically a box, open at one end to slot onto the main body of the gun and was also built up using foam PVC. The curves on the top and long bevel on the bottom used method 2 while all the rest used method 1.



On to the main body of the gun.

Two sides were cut out using a template created from my blueprints. The rear of the gun was extended to give a point for the stock to slide onto. The same was done at the bottom front for the front ‘grip’. Before using these to build a hollow box, I built the circuit for the LED and dial. When done, the switch was secured in place inside and everything was put together. A smaller template was created by cutting off where the bevels and curves would be. It was then used to cut the shapes from foam PVC after which I attached them to the sides. To create the panel lines on the sides I used 2mm styrene – this also had an added benefit of making it more sturdy. The curved sides used method 2 and bevels used 1 as described above. When dry and sanded, panel lines were carved into them using needle files. Holes were drilled on both sides using the template for the screws and studs. The mount rail along the top was 3d printed, glued together and sanded before being attached. Finally details such as grub screws, studs and dials were added.





20170801_111622.jpg The muzzle was a 3d printed part, done this way rather than spend time looking for a correct sized tube or lathing and drilling. It was attached to it’s mount and the sides beveled using method 1. This wasn’t attached straight away as I used it to help construct the front section of the gun.




The front grip was constructed in a similar manner as the main body, making sure it would slot on correctly. l. Along the sides were 3 beveled indents. I used my template to work out the positions in each indent and then did them one bevel at a time usng method 1. Making sure each was level and sanded before moving onto the next. With all the bevels done, holes were carefully drilled and grub screws inserted. When done this part looked a lot like a boat hull 🙂

At this point most of the prop was done. With only the sights and magazine to go, I opted to work on the sights. These both consisted of 2 side ‘pods’ with a connector and sight mount between them, the only difference being the size. They were constucted from Foam PVC, 3d prints, acrylic rod and styrene. Before making the pods I created a cross section template to make sure they would correctly fit on the mount rail. The pods were basically small hollow boxes with beveled edges with grub screws and small dials were added for detail. Care was taken when drilling the holes for the rod to pass through. Any mistake would mean it wouldn’t sit flush to the rail. The front sight was a 3d printed rod, while the back was carefully cut and drilled from 2mm stryrene. For some reason I had a lot of trouble with he front pods: they just wouldn’t sit right on the rail. I decided that rather then waste more time I 3d modeled and printed them out while working on the magazine. When painted it is hard to work out which pods are hand made and which were printed.








The magazine had to both hold the batteries and attach to the gun. With this in mind it was constructed hollow with a space for the holder to slot into. I used styrene on the left and right sides to create the panel lines. The magazine has many circular indents. Using templates these were first drilled out and then the hole filled. A paintbrush with a rounded end was then pressed into the filler producing the desired effect. To attach it to the gun I added 4 pegs in each top corner and drilled matching holes. This allowed it to slot on and hold it in place.








With all the parts complete the front grip, stock and trigger/grip were glued in place. Any gaps were filled and sanded down. After many passes of spraying/sanding/filling I gave the whole prop a coat of silver paint. This was followed by 2 coats of black spray. When dry the black could be scraped or rubbed off.

Before any weathering, I drew out on inkscape, printed off and cut out many vinyl decals that decorate the gun. I had trouble working out how to do the tiny lettering and put up a post on the PropTarts group for suggestions. I got a lot of great suggestions and one of these pointed me to small vinyl lettering that was available. I ordered some of these and they worked out great.  Weathering was then added with a mix of brown and black paint. A little more brown as added to this mix to make it stand out from the black.





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