GREEN HORNET "Sting" Gas Gun: A Build Log

[Astyanax]

Hi all:

I am working on a replica of the Green Hornet Gas Gun for RPF user cjunco1937 (the "client"), and I thought it might be helpful to go ahead and post a build log here.

This is a design project too, and it's only my second commission, so I'm very interested in feedback, red flags, pitfalls, anything you might see along the way that might help!

This thread will catch up to current state (I'm approaching the halfway point), and carry forward the rest of the build. Hope you find it interesting!

---

THE PLAN:

The request here is to design and build the Gas Gun components as a "conversion kit" for a Denix Mauser C96 replica, and then install the kit, paint and weather it. I'm designing everything in TinkerCAD, and printing parts on my shiny new Elegoo Saturn 4 Ultra 12K resin printer. I expect minimal sanding along the way as a result.

The client provided the Denix, as well as some real CO2 canisters that he wanted me to consider if they could be used as a found item in the build.



REFERENCES:

The traditional Green Hornet character exists in old black and white serials/movies, as well as a run or two of comics. The plan was to synthesize a final look from all of the sources that would make the client happy. We gathered these references:




Notice that in some cases, the gun uses hoses to connect the canisters, and in others there's a "rail" and "ejection" mechanism instead. Also, in a couple shots there are a total of five canisters, which the client found particularly appealing. Some replaceability of the canisters would be nice, but no other mechanical aspects are part of this project.

It occurred to me that magnets will come in handy here.

PREP:

The first thing I did was try to make some decent photos of the physical Denix I had received, so that I could print them at actual size and do some sketching:



After some Photoshop cleanup and significant brightening and resizing, I had this to work with, printed on 11"x17" paper:



And with that I got to sketching!

 

[Astyanax]

These were my initial sketches that I shared with the client, brainstorming across all the references, with a few notes that he gave me:

• Try to get five canisters (4 vertical and one horizontal) in there.
• Try to fit real ones if possible.
• The oversized cap on the barrel end is cool.
• The gun can be modded if necessary (I'm trying to avoid this).
• Any kind of removability or replaceability of parts would cool, but don't sacrifice stability.

I quickly realized that five full-size canisters will simply not work:



This meant that we'd have to sacrifice either the size of the canisters or the quantity...

---

SKETCH #1: RAILING

First off, here is a version where the look of a "rail-eject" system might work. The cartridges were shrunk from 2-1/2" long to 2", and space has was left for the perception of swinging rotation. I thought we could maybe stick a hose or two in the empty space for looks, but it seemed weird to do so. The connections between cartridges would be little "brackets" that help hold them in place.

The canisters are mini-printouts that I cut out and taped to the sketch.

---

SKETCH #2: HOSES w/MEDIUM CARTRIDGES

For this version, I shrank the cartridges to 2-1/4" inches long, and squeezed them in as tightly as possible. This required making those hose shapes a little different than the comics and serials. The connectors between cartridges would be hoses instead of brackets.

---

SKETCH #3: HOSES w/FULL SIZE CARTRIDGES

I saw that it WAS possible to use the full-size cartridges, IF we reduced the count to 4 instead of 5, and adjusted accordingly. The connectors between cartridges would be hoses instead of brackets.

I was keep in mind that if we used the original cartridges, removability is probably not an option because they are so heavy. But the tradeoff is the "found parts" coolness.



I felt this was most authentic to the serials and is not terribly off from the comics.

---

The client really wanted to go with five canisters for the final look, as well as hoses instead of a rail-system. So Sketch #2 was decided to be the one to build from.

 

[Astyanax]

After taking all of the above into consideration, I mocked it up in Photoshop, with a final canister length of 2-3/16".



Notice the cross-section in the lower right. This was how I envisioned the canisters sitting in the bottom rail:
There will have to be round "pits" in the rail to help hold the canisters in place, plus magnets!
There will also be a number of magnetized "ports" on the canisters, so that mini hose sections can be attached/detached and the canisters can be removed (vertical canisters only).



The client approved the design with some small mods.

First, some suggested color changes to match the Green Hornet's costume, with black hoses and yellow connectors and ports.



I mocked up those changes, and then I tried on the logo for size. But it made the gun look too much like a toy:



Then, we realized that the yellow components might look really good with a bright brass finish instead:



Yes, now we're talking!

So we were just about good on the design, so I started modeling.

 

[Astyanax]

I fired up TinkerCAD and modeled some of the easier parts first. Connections and fit will really be focused all around the canisters, so I started with them.



I also settled on 4mm x 3mm neodymium magnets for this project. They should be quite string when paired up.

Next, I mocked up a mini hose so that I could check spacing and fit. The hoses will NOT be hollow, but serve more as rods, really. This should increase stability.



And some test prints!



The magnets fit the ports and canisters well, as did the port themselves fit in the canisters, so I felt I had my tolerances dialed in.

 

[Astyanax]

Next, I took my first pass at the vertical "bracket" that will be attached to the front of the magazine chamber.



A test fit, and the height was off, and the curve was not deep enough to the fit the mag nicely:



I'm thinking I will attach the bracket to the gun using E6000, which is very strong and least likely to affect the Denix itself. I'm trying to avoid drilling and tapping holes for this project.

After a bit of tweaking, I had a much better fit:



With the fit at acceptable tolerances, I went ahead and finished the details on the bracket. Updated version printing as I write this!

 

[Astyanax]

After printing up a bunch of ports, I wanted to glue in some magnets, all with similarly aligned poles.

I did this by first making some paint sticks by supergluing larger magnets onto the ends of bamboo skewers, all in the same pole alignment, of course. Once glued on, I can use the sticks to maintain the same pole alignment for any magnets I was using!



Then it was a simple matter to place a magnet on top of that, put a little superglue inside the base of the port, and place it over the magnet to cure.



This ensured that not only will ALL PORTS have the same pole alignment, but the magnets are now flush with the bottoms of the ports.



Next, I took my first dozen ports to the paint booth, and airbrushed them with Alclad II Black Gloss Primer.

 

[Astyanax]

In the meantime, I designed the "cap" that goes on the tops of each of the canisters:



The updated bracket and some of these caps are now printing, as well as a "short" version of the port that goes in the bracket.
And now we are caught up to the present!

 

[Astyanax]

The dozen ports were given a coat of Alclad II Polished Aluminum:



....and then a coat of Alclad II Candy Golden Yellow and Candy Red, mixed at a 5:1 ratio, sprayed at medium heaviness.



This gives kind of a "bright brass" effect and doesn't sacrifice much of the shine. If I were going for gold, I would have sprayed a bit more lightly.

 

[chubsANDdoggers]

Looks great. Fantastic start Bill!!

 

[Astyanax]

Looks great. Fantastic start Bill!!

Thank you, sir. High praise!!!

 

[Uridium]

Always great to see an uncommon prop being made, and very educational to follow your build. The time you have put in to document and share the process is appreciated, and extremely useful for us who consider ourselves more in the 'beginner prop maker' category.

 

[JamesM242]

Astyanax - thanks for sharing your work! What a cool project!

 

[Astyanax]

Uridium and JamesM242 - Thank you so much for the kind words...I'm still a newbie in a lot of ways, just really immersed myself in the last year!

 

[Sundowner]

Coming along nicely! I have never seen this version before but I love it!

 

[cjunco1937]

Coming along nicely! I have never seen this version before but I love it!

Yeah I hadn’t either until I started working on the GH cosplay and when I got to the gun, I was underwhelmed with the choices. The Van Williams version (which is the first one I got) is meh …

Then I looked at the one from the recent film and I liked it even less. So I didn’t consider it.

And then I went back and looked at the 40s serials one, which is basically the same one that is shown in the recent dynamite comics run and I really dug it.

I loved the fact that it’s on a C96, since I’ve always loved that gun, even before I started collecting different variants of the DL44. So I got a Denix, and put it together with some of the vintage gas canisters that I had acquired as part of my Han Solo belt Greeblies and I figured… “great! This can totally work!…”.

I tried a different set of canisters (below) but I preferred the ones shaped like hour glasses (above)

Anyway, that’s when I reached out to Bill to work his magic on this baby, which he has more than done, as you can see from his posts above.

 

[JamesM242]

cjunco1937 - looking forward to seeing the full outfit!

 

[cjunco1937]

Working on it…

 

[Astyanax]

Printed the final bracket and some caps for the canisters. Need to do a little sanding!

 

[Astyanax]

Got a whole lotta sanding done!



And yes, that's a lot of extra parts. I printed up a lot of extras, so I can be stress-free in making lots of mistakes. You go to school on the first one; failure is REQUIRED for skill building. I plan to finish all the extras all the way; in my experience, attrition takes one or two every step or so. Any leftovers will go to Mr. cjunco1937!

 

[Astyanax]

Also, since I printed up an extra couple brackets, I broke one in order to see how strong it was.



It was hard to break. It hurt. No brittleness and just the faintest bit of flex!