Sunday, April 14, 2013

Making the STA-52 Light Assault Rifle From Killzone

A while back, I got a message from a very talented 3D modeller named Hugh Holder who had made a pretty decent digital model of one of these:

This is the STA-52 light assault rifle used by the Light Assault Infantry troops of the Helghan Empire.  From one title to the next in the Killzone series there are some minor changes in the design, but nothing significant.

With the 3D modelling  done, he asked me if I'd be willing to build it for him.  No problem.

Here's a couple of copies of the finished piece:
STA-52 LAR Pair Painted

To see how they were made, read on.

The original model was alread split in half and laid out for cutting, but because Lopez (my Craftsman Carvewright CNC machine) is only able to cut 3/4" deep, I had to slice each side in half on the vertical axis.  Here's a screen shot showing the layout for one half in the Carvewright design program:
STA-52 Parts Layout

Satisfied that the layout was as efficient as possible, I fed it to Lopez and he spit this out:
Helghast Rifle First Quarter Cut Out

Then there was some general screwing around:
Helghast Rifle Right Half Fit Test

While I was goofing off, Lopez cut out the other half: Helghast LAR 2nd Half CNC 4

Then I glued the two halves together: Helghast STA-52 LAR gluing
Some days there just aren't enough clamps.

While waiting for the epoxy to set up on the main body, I coated the top rail/carrying handle with more epoxy:
Helghast STA-52 LAR carry handle and rear sight
Meanwhile, Lopez whittled out the pieces of the rear double drum magazine:
Helghast STA-52 LAR Magazine Roughed

With the epoxy set up on the main body, the next step was to sand it smooth:
Helghast Rifle Sanding Detail

Since Lopez is a 3-axis CNC machine with a tapered cutting bit, he can't cut perfectly vertical faces.  Instead, I have to go back and square up a few spots were there are problems.  In this case, this meant rebuilding some of the narrow ridges with strips of styrene STA-52 Fastener Details

Somewhere in the myriad cycles of sanding and filling, I continued working on the drum magazine.  In order to make it as believable as possible, I had a friend of mine (who does a lot more shooting than I'd ever have time for) send me a bag of inert NATO 5.56mm rifle rounds.  As luck would have it, they fit perfectly: 
Helghast Rifle Magazine details
I carved grooves into the drum to fit each of the rounds and then glued them in place.  Here's the first stack in position:
STA-52 Magazine Begins 
And the second: 
STA-52 Magazine Details continued

Back to work on the main portion of the rifle, I'd started adding various rivets and screws to increase the realism:
  Helghast Rifle Progress

Nearing completion, I crosshatched the grip by hand using a triangle file: Helghast Rifle Grip Progress

To get an idea of were I stood, I sprayed the main body with black primer: STA52 Ready to Mold

Satisfied with the overall shape, I tied it to one of the rafters in the workshop so it would be out of the way for a little while.

"A little while" turned out to be almost a year before I had a few moments worth of down time and I started making a mold. 

Step one was building a box: STA52 Mold Box

Box built, it was time to build up a bed of clay for the rifle to set into.  This will determine the shape of the parting wall that separates the two halves of the mold.  In order to make the two halves register together properly, I pressed a bunch of dimples into the clay surface with the round end of a sculpting tool: STA52 Clay Wall

Then it was time to pour in some rubber: STA52 Silicone Pouring

Here's the first half of the mold poured and waiting to cure: STA52 Silicone Curing 
The next morning, I flipped the whole thing over, removed the bottom of the box, and picked out the clay:
Removing Clay Wall

And picked out the clay:
LAR Cleanup1

And picked out the clay:
LAR Cleanup2

Once I'd removed all of the damned clay, I sprayed the silicone with a mold release to prevent it from bonding to the second half, then poured more rubber on top of it:
Helghast Rifle 2nd Mold Half

Since this would be a very large (read: "expensive") block of rubber, I filled some of the space away from the prototype with chunks of cured rubber cut from retired molds:
Helghast Rifle 2nd Mold Half Filler Chunks

Here's a closer shot showing the chunks sinking in:
Helghast Rifle 2nd Mold Half Filler Chunks Closeup

To make the surface smooth, more rubber was poured on top:
Helghast Rifle 2nd Mold Half Poured

After the second half had cured, it was time to disassemble the box: Helghast Rifle Mold Box Dismantled

Then separate the mold halves: Helghast Rifle Mold Opened

After removing the original, I cut sprues and vents into the rubber.  Then the next step was to cut down the sides of the mold box so that the rubber sits about 1/4" above the wood, then I reassembled the whole thing and fitted hanger bolts to the top edge:
Helghast Rifle Mold Ready to Close

When the lid is bolted onto the box, tightening the nuts works to squeeze the two halves of the mold together and minimize flashing.  Then it's time to pour resin into the butt end of the rifle.

The small parts required simple block molds.  Here's all of the pieces laid out:
STA-52 LAR Kit Parts 

I made multiple copies:
Helghast Rifle Casting Lineup

It's always hard to be serious at this stage:
Helghast Rifle First Two Castings 2

Here's the first cast of the magazine next to the prototype:

With a handful of decent castings cleaned up, the first thing I did was prime them and spray on a gold basecoat:
Drum mags base color

After a bit more paint and the addition of a section cut from a clear plastic map tube, they really started to look the part:
STA-52 LAR Primer 3

The rifle was given a basecoat of "magnesium" from the Model Masters line of metalizers:

Then I picked out the black parts:
Base colors

Some of the pieces of the action were picked out in "gunmetal" metalizer, then the whole thing was given a blackwash:
STA-52 LAR Pair Painted

Again, progress slowed a bit due to some generalized screwing around:

To add a bit more age, I also added a rust-colored wash in some places:
Once I was satisfied that they looked like they'd seen some long months battling the ISA on the fields of Vekta, I was finally ready to call them done:
STA-52 LAR Pair Finished

STA-52 LAR Pair Finished 2

Of course, now that I've got the rifles, I can't help but think I really need the rest of the outfit to go with them.  First step, the helmet:
Helghast Helmet Dome

More on that some other time... 



  1. Absolutely great work on this.

  2. Ah man, that it cool :P smashing work!

  3. Nice job.
    from France

  4. any chance you're selling any copies Y.Y i want one on my wall

  5. I'm glad you had as much fun making this as I did reading it!

  6. That's pretty amazing. Next step ... SENTRY DRONE!!

  7. Please make VC32 Sniper Rifle next, my favourite gun from Killzone. Sta-52 is my 2nd favourite :)

  8. They look siiiiiiiiiick!!!
    I wanna buy one ^__^

  9. jerrod garrett07 May, 2013 10:59

    i want one

  10. OMFG!!! the ultimate gun finally came to life! great job man, great job

  11. nice work looks real!

    how much I want to buy it!

  12. i would buy this for 250 that's a good price right? the helmet 150 eh?

    1. Maybe a good price for you.

      Bear in mind that even with the help of the CNC machine, the prototype took a great many hours to bring to life, then the mold took a lot of work, then there's the labor involved in casting, trimming, painting, and weathering.

      And I've not even mentioned the costs of materials involved.

    2. Ok so I love the Killzone games. Do you sell these replicas? If not I think you could start a small business doing so.

  13. Amazing work. It's a hell of a gun.

  14. If i get up like $2k, would you make one for me? or is that too low? I actually have a replica with an orange tip that is oversized but this one is 100x better..

  15. Amazing, I would buy one!

  16. it's a masterpiece! in Russia, I do not know of masters who could do the same. and I really want to have the same home! Do you have the option of sending one in Russia!? for gratuity, of course.

  17. These are truly amongst the wonderful informative blogs.gut