Building the Fury Gun: How NOT to Build a Prop

A complicated fantasy firearm, moving parts and lots of metal in a small apartment?  What could go wrong?
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Step 1: The Concept

As mentioned in my previous Instructable, this was a non-firing replica of a weapon that never was; the heroic and dangerous 45mm double-barreled break-open grenade launcher carried by 1930's pulp adventurer Mr. Fury.

The original concept was to make use of the growing technology of 3d printing; to model the complete weapon in 3d and print out the parts that linked several military surplus parts that looked cool for the project.

It ended up with me doing serious metal working in my apartment, with inadequate tools.  The biggest tool I had was a budget, bench top drill press from Harbor Freight.  Most of the serious cutting was done with a hacksaw!

I also made some serious errors, such as being misled by my experiences with welding steel to think I could braze multiple brass parts together in the same way.  In the end, the thing was as much epoxy and other glues as it was metal, and in hindsight we really could have printed more of it, done a lot less metal work, and saved ourselves much time and money.

Step 2: Importing the Parts

The first step was to bring the existing parts in to the scale-accurate 3d model.  To avoid lens distortion I placed the pistol grip on top of my scanner and SCANNED it in.  Then I aligned and scaled it (as described in a previous Instructable).

The other parts were done by hand...calipers in hand, frequent measurements, lots of playing with scale tools and grid settings.  Early on I set the project in metric...and then it turned out almost all of the important parts lined up better in Imperial units.  Not only that, there is STILL a bug in Carrara Studio wherein if you set the workspace to metric it multiplies all numeric entry by 2.54 (the number of centimeters in an inch, natch).

can this thingy use as a grnade luncher?
nomuse (author)  assassino desigen1 year ago
Well, yes but mostly no!

It was designed to be dimensional with certain real-world rounds -- because that gave us more options for associated props. And the original design did have functional trigger and hammer fall -- there is actually an open hammer (but no spring) on the breech face.

However! There isn't a pin, and the breech cover doesn't lock (and is plastic anyhow.) Nor is there any space or gripper to hold a round against the breech face.

We pretty much fudged the entire question of "how does it hold the round in?"
This is probably the most worked and planned out prop manufacture I've seen!
Though I must say it looks amazing.... (What got you into using really parts from other real firearms?)
The Rambler2 years ago
This is one of the most beautiful and realistic props I have seen. I wish I had the resources, the time, and the know-how to replicate what you've done here.
nomuse (author)  The Rambler2 years ago
Well, thank you for saying so. I like it okay myself..I think the treatments came out pretty realistic overall (thanks to the Replica Props Forum and several informative posts), and I think it has some of that gangly look of real between-the-wars firearms.

That said, the whole point of my Instructable was about making do with far too little. I admit freely I finally broke down and spent an hour at my brother's wonderful shop. Would that I could go there more addition to 15" cold saw, MIG welder, and power bender, he owns his own 4' x 8' ShopBot!

But I could have done the welds elsewhere, or paid a local sheet metal company a few hundred bucks to do them. Everything else was marginal tools...mostly a single Dremel...and hand-sculpting with such wonder materials as Apoxie Sculpt and 3d-printed Alumide and Stainless Steel.

If I had to quantify the things that really made it possible, it would be patience, planning, long experience with hand tools, and my theater-trained sense of where and how to fake it (when you couldn't do it right).

It is really those new materials and new forms of access -- such as Tech Shop, the rental tool place -- that make it possible for us amateurs to make things we didn't think were possible. All I can say is start small, have a plan, and embrace failure -- it is from failure that one learns. If you are afraid of failure you will never start anything. But if you fail enough you learn how to turn it into just part of the creative process.

Hrm. I think I have another blog entry there. So...thank you again!
sergio002 years ago
glitchus3 years ago
That 45 mm looks absolutely real. I certainly wouldn't want to be looking down the wrong end of that thing! You need (well, we all need) a serious machine shop rather than an apartment. You do know that there are 37 MM flares available (hint) for that added touch of realism, if you were to fabricate an all metal MK II, Just don't catch the woods on fire!
nomuse (author)  glitchus3 years ago
The flares are one of the things that got my friend into the original design spec. Actually, he also wants me to build or modify (the Japanese made one) a double-barrel flare launcher. Also non-firing, I presume.
glitchus nomuse3 years ago
if your interested in going to the 'next step' in realism, check out these guys for some ideas in munitions:

'Grog', evidently has reloading data for 'home-brew' exotic munitions. I haven't ordered his 'disc' yet, but I've been thinking about it, as it would save a lot in 'trial and error'.
glitchus3 years ago
What the heck did that trigger group come out of? I initially thought it was from a WW II PPSh-41 Russian submachine gun but it's not. I'm curious, as an amateur antique gun collector.
nomuse (author)  glitchus3 years ago
Not too far off. It's a 1924/29 Chatellerault trigger/frame assembly.
doomsdayltd3 years ago
wow just wow this prop is a beauty, you are a excellent craftsman making this top notch prop in just your apartment. This is hands down (other than movies) the best prop i have ever seen, the d@mn thing looks like it could fire and good work with the old gun parts added. I wish i could see this in person, keep up the good work, oh and last thing is this prop of your design or based upon something else other than the double barrel shotgun :D
nomuse (author)  doomsdayltd3 years ago
Thank you for the wonderful comment. My biggest disappointment is that the metal-to-metal braze I had planned for didn't work -- if it had, the final thing would have been as strong as a real weapon. As it is, I can brandish it one-handed, pick it up by the stock even, but if I drop it on a concrete floor...

We're hoping to take some proper pictures of the final thing this week.

You'd have to ask my client/friend, the gun nut, about where he came up with the basic design. It is extrapolation from period arms; there are 30mm flare guns in the period, including a Japanese over-and-under double barrel pistol. The 45mm shaped charge is similar to actual rifle grenade rounds. Where he thought of firing basically one out the other, I don't know! The rest of the design evolved from the premise, particularly, that it had to both break open to reload, and slide backwards against a strong spring to take up some of the recoil of pushing a 45mm shell down range.

Since I'm not a gun expert by any means, there were quite a few emails and luncheon sketch sessions where he'd say "Make up some part for here," I'd make up a part, and he'd say "No real gun ever did it THAT way. Here's a sketch of what those really look like." So it evolved cross-wise. I am happiest that we made very few compromises based on what we COULD build as opposed to what we WANTED it to look like. The trunnion leans furthest in that direction; the design of the trunnion is entirely based on the kinds of shapes I could achieve with materials at hand that could take the forces involved.

Still, I finished the project with a strong desire to make a laser pistol carved from a single block of wood, with NO moving parts, and no metal. (Unfortunately, what I've done since then is experiment with a mess of electronics I've now got to somehow fit INTO that proposed wooden shell!)
wow sucks if you drop the thing :( but um i think it will be a slightly big feat to carve a laser pistol from block of wood but i wish you good luck!
scoochmaroo3 years ago
Wow. Well, the finished product looks great!

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