Design an Airgun contest, Part 2
Writing as B.B. Pelletier
This report covers:
- Several entries
- Norica bullpup
- Nerf gun
- Two great entries!
- Maximus Blowhardus
- Learned something
- Spaghetti blowgun
- Catapult gun
- Without further ado, My plinker:
- Some of the features I incorporated:
- Penny shooter
- The simplest entrant
- A hard job
Today we learn who is the winner of the Design an Airgun contest. It began on September 10 and was supposed to end at the end of the month, but several readers asked me to extend the closing, so I did. The contest ended last Friday, October 16.
There were several entries. Some were blue sky dreams and nothing was built. I didn’t take them seriously. But some folks submitted more than one entry and they built all of theirs. I considered everything on the basis of the contest rules, which were:
1. I’m guessing it will be a BB gun, but it doesn’t have to be.
2. I’m guessing it will be a smoothbore, but again, it doesn’t have to be.
3. When I say build an airgun, it doesn’t have to work with compressed air.
4. It can be any kind of powerplant — so long as it doesn’t use an explosion to launch the missile.
5. The winner would be the niftiest design that the most people could build.
Now let’s see what people did. First is reader Jim.
This project was done back in the early 1980’s. It started as a semi-finished Norica model 61 air rifle sold by Beeman. The original kit consisted of an air rifle with an un-finished stock. I suppose the idea was to capitalize on the popularity of unfinished muzzle loader rifle kits at the time.
I had the opinion that the sight must be mounted to the barrel for accuracy, as opposed to the typical break barrel with the sight on the receiver. Since this moved the sight forward, a bullpup design would place the eye closer to the sight. It is interesting to see how popular bullpup designs have since become.
The stock is carved from several birch boards glued together. Finding a location for the rear action screw drove the length, with locating it above the pistol grip. The trigger transfer mechanism is steel, with lightening holes drilled to remove mass. I had limited access to shop equipment at the time, so the construction is a bit crude. The stock is Accraglass bedded to the action, again with the idea of improving accuracy.
The Norica trigger was moved forward for the bullpup design.
The sight is an all-plastic ambient light red dot sight of unknown origin, but was cheap at the time. An aluminum spacer raises it to eye level.
The sight uses ambient light, so no batteries are required.
Accuracy was very disappointing. At the time, all I had were Beeman Silver Jet pellets. The rifle has not been shot in years. But knowing what I now know from the various articles of tests & tuning from master Gaylord, I may give this gun another try.
This is one of reader Jim’s first two submissions. It was submitted almost as a guest blog, so I decided to make it look like one. He clearly did a lot of work to this gun! Could anybody do it? Probably not. But we can all appreciate it!
Submitted at the same time by Jim is this plan to build a Nerf gun.
Back in the early 1990s I built three Nerf® guns from PVC pipe. This was before the huge proliferation of styles now available. I tried to give the guns an ‘authentic’ look that would not be accepted in public.
Homemade Nerf gun.
Now, having some shop access, I was able to turn the PVC parts and make the rest of the parts. The barrel is several layers of hobby tubing soldered together to fit the dart and the PVC fitting.
Sights are strictly cosmetic. Rear sights were salvaged from other air guns that were converted to scope use. The front sight is a brass blade soldered into a screw slot.
Nerf gun rear sight.
Nerf gun front sight.
The piston head originally used a piece of urethane machined to provide a ‘parachute’ type seal. However, like my FWB 124, the urethane eventually hardened and broke apart. I added an O-ring seal instead, but never removed the remains of the original urethane.
The Nerf gun piston.
I have yet to modify my other two pistols. The spring is just a hardware store spring. Parts are lubricated to increase velocity as much as possible.
The triggers are surplus M98 Mauser triggers I purchased from an advertiser in Shotgun News. The trigger mount is silver soldered to a steel tube to position the trigger to the sear. Aluminum and brass collars center the tube to the external PVC body.
Here is a ’98 Mauser trigger attached to the steel tube of the Nerf gun.
The sear is a collar pinned to the piston/ cocking rod and is chamfered to allow the trigger to reset when the cocking rod is pulled back, it has been hardened to reduce wear. Shown here is the relationship of the trigger to the sear.
Here’s how the trigger interacts with the sear.
I added a spacer to the cocking rod to prevent the piston from slamming into the plastic PVC fitting when fired. Several fittings were broken & remade before I limited the piston travel. A couple of O-rings help to dampen the hard stop (shown on the handle that’s pulled out on the rear sight photo). The grip is bent square brass stock with walnut grips cut to fit — also shown on that photo.
The finned Nerf darts sail quite nicely, and will fly about 40 feet. My daughters were in high school at the time, and these were very popular when they had friends over.
Two great entries!
These were two great entries. Unfortunately they were submitted in Microsoft Word format that contains all sorts of embedded code, so they took me many hours to sort out and strip off the code that couldn’t be used. Plus the photos were embedded in the document, which means they had to be pulled out and reformatted. Most word processing programs are not friendly to online publishing software. If you want to submit a guest blog, please ask me because I have to give you some submission guidelines first.
Jim also sent a great submission of a pedestal-mounted potato gun cannon. It’s even more complex than the first two, and I am saving it as a guest blog of its own, if I can get Jim’s permission. But here is a picture of it.
Reader Jim also gave us a potato cannon submission that I hope you will read about in the future.
Reader pacoinohio whom I once jokingly called Pinocchio (and I heard about that from many readers!), sent us his submission that he calls Maximus Blowhardus.
Well I’ve been thinking about my entry. What to do? What to do? They say you should play to your strengths. I am after all a plumber. Not really, but I do know The Prime Rules of Plumbing — Water runs downhill; you get paid on Friday; don’t pick your nose on the job.
So, here is my gun plumber entry that I call—
It is simple pieces of black iron pipe, a couple of brass ball valves and some PVC bits.
Design criteria began with caliber selection which was dependent on projectile availability. Found a bag of wine corks that seemed suitable, so I settled on 1” pvc. Power supply? Oh yeah, air compressor in the shop. That helped with the rest of the parts selection.
Took about 20 minutes at the big box store to get everything and another 20 minutes of assembly. Hooked up the air hose. Compressor is regulated at a modest 100 psi. Inserted a cork in the barrel, filled the reservoir and then attempted to fire. Stress ‘attempted’. The cork did not fly. Too much air passing by. Paper patching to the rescue.
I wrapped the cork with paper towel (Brawny for those taking notes) for a moderately snug fit in the bore. Second shot went about 25’. Hmmmmm……. what if I dampened the paper patch? This allowed for a tighter wrap and resulted in a 30’ distance. It also revealed that the bore was filthy. Yeah, I reused a piece of PVC. Important lesson — Always clean the bore. Brief break to do that and then back to testing.
Up to this point, I had been using both valves. Fill reservoir, shut off fill valve, then open discharge valve. On the next shot, I did not close the fill valve and just opened the discharge valve. Almost 90’ distance. Enough.
I think I have achieved proof of concept. Low pressure requires a large volume of discharge air. On the last shot I had added the air compressor tank and air line volume. So next step is to reduce caliber of bore. I think I will go with 1/2” and continue firing tethered for maximum air. I will have to turn the corks to size. Toying with using o-rings to seal to the bore. Lots of options of size, material, durometer, etc. And then there is lube. Have to polish the bore of the new barrel. So many rabbit holes.
Well, we learned something from Paco’s submission. If you are going to shoot with low air pressure, you need plenty of it. One-hundred pounds per square inch may sound like a lot, but to airgunners it’s definitely low pressure!
Reader minuteofsomething made an unusual submission in the form of a You Tube video. Let’s watch.
Now, I have to say, this one is so simple even old BB could do it! And he shot it to some distance that I will guess was 15-20 feet. So it doesn’t just shoot through cans, it shoots to a good distance.
This one comes from reader Airman of the Board
I present for you my entry into BB’s Airgun Design Challenge. It is a single shot rubber band powered catapult gun (capable of launching BBs as well as other appropriate projectiles of your choice) built from what I had around the house.
First, however, I would like to thank BB for having this contest. It motivated me to spend a lot of time in the shop this last week week and a half. Burning the midnight oil, as it were, solving design puzzles and trying new techniques. I am excited to show you all what I made. But first a few words about what I was trying to accomplish with my design.
As a long time reader, but first time poster, I hope I am not “oversharing” with this long post. I put a lot of effort (>40 hours) into this project and I am hoping it is something you all might be interested in.
BB said,”The winner would be the niftiest design that the most people could build.”
So that the most people could build it, I wanted my design to be low risk. A project for people with limited tool use and fabrication experience. A design were if something were to go wrong during the build or with the final product, the gun would not be subject to catastrophic failure, thereby unleashing a lot of pent up energy. Perhaps other novice airgun builders would be like me and find the complexities of starting to work with high pressure air, or controlling the power of a high strength spring intimidating. The design should also favor simple parts that don’t require tight tolerances and complex machining.
I do not wish to presume BB’s intention behind this design challenge, but I speculate it was to offer people the satisfaction of making something for themselves, and participating in a new facet of a hobby that fascinates us. It was not, I imagine, an attempt to uncover an airgun engineering savant among us. As amateur airgun designers we are unlikely to best the professional engineers working in this field. This suggests that this challenge was not about making the most refined, powerful or elegant design, but rather something that offers the individual the satisfaction of making something from scratch, the use of which would provide that other joy of man: launching projectiles. A plinker, that he or she made.
Without further ado, My plinker:
Drawing obvious inspiration from the Sharpshooter catapult guns that BB has featured on this blog, this “airgun” is a single shot rubber band powered launcher that I believe could be made various ways with relatively few tools. I made every piece of the prototype from readily available raw materials. The only parts I didn’t make were the screws, a coil spring scavenged from a retractable pen, a small magnet, and the rubber bands. I finished the project about an hour before I wrote this, so there has only been preliminary testing. I have not tried to tweak the performance, but think it is fair to say it will not satisfy the airgun connoisseurs desire for precision long range shooting equipment, but it will hit the broad side of a barn (I have been able to repeatedly hit a can at five paces). The piece favors an artillery hold. I don’t know how lightly it likes to be held, but you better point it up if you want any distance. I would rather get hit by the pea than the pea shooter, if you catch my drift.
The heart of the design is a cylindrical bolt in a slotted tube. The bolt is attached to the tube by means of elastic bands, which drive the bolt forward to propel the shot. The bolt face has a conical recess to accept and center the BB. The design could be made as simple or nifty as you desire. Simple: tying rubber bands to a PVC tube with a wooden dowel bolt that has another wooden dowel running perpendicular through it. The slot in the PVC could take a right angle dog leg at the rear to act as a bolt catch and rudimentary trigger. Or you could build it as I have here. What additional features and style you add to the basic premise depend on your abilities and desire for “niftiness”. Because I assumed the purpose of building one’s own airgun to be the pride of ownership and satisfaction of having made something, I saw no reason not to make as many parts as I could, and spend the extra time to make it nifty.
Some of the features I incorporated:
- Figured Maple stock with checkered walnut grip panels.
- Cold blued steel main tube and bolt
- Adjustable (for sear engagement) trigger with steel sear pin (pictures upon request)
- Aluminum trigger and “sear bar” (bar under main tube)
- Magnetic bolt face to retain steel shot.
- And to help the marketing men:
- Free floating barrel
- Polished Aluminum main tube end caps (barrel shroud?)
- I think it has a Buck Rogers on the American frontier– ray gun meets Kentucky long rifle vibe.
Thanks for checking it out. Let me know if you want more pictures.
Now to go clean up the shop…..
A picture is worth a thousand words:
The AOB catapult gun.
Catapult gun parts.
That entry is one after my own heart! I have always wanted to test a Hodges catapult gun and Airman of the Board has shown us how to make one! Of course his pistol plans would need to be scaled up to make a long gun, but it’s all there.
I also think this is the beautifulest entry of the contest!
Airman of the Board also submitted a design for another catapult gun that’s a coin shooter. It’s similar in function if not design to the Turnpike Toll Gun I reported on in 2013.
I present, for your consideration, another entry into BB’s Airgun “as long as it shoots something at a target” Design Contest – The Penny Arcade Shooter.
The penny shooter.
Penny shooter cocked.
What we have here is a catapult-style penny-shooting three-shot derringer. Three cents can be loaded into the “magazine” cutout on top, and each in turn is automatically loaded into the chamber/ barrel as the charging handle is pulled back. It has a spring-loaded penny catch and trigger mechanism, straight blade brass trigger, and open sights. It is made from Red Oak, .125” brass rod, some thin plywood (.15”), a small bit of music wire, and rubber bands.
Penny shooter parts side view.
Top view of the parts.
The design could be built with only the most basic woodworking tools, and the materials could be altered to what is on hand/ available. (Paint stirrers, popsicle sticks, small nails and pen spring?) The design could be scaled to the denomination… ahem..caliber of your choice. Ammunition is likely already on hand, and is cheap, especially since it can be reused.
I built it in a day, along with an arcade (cardboard box with rod running through it from which 3D targets are suspended) that my partner and I got a kick out of using indoors that evening. She got the hang of it quickly and was hitting a 4” target at 5 meters.
One could even just build the barrel and plunger mechanism and use rubber bands to manually shoot coins. But, if you want my two cents, (which is over half of this gun’s basic load – ED.) it is worth building the handle and trigger mechanism. It does not have to be that precise. Just as the act of marksmanship brings with it the joy of seeing your sphere of influence projected beyond the direct reach of your hands. A similar enjoyment can be experienced with the construction and use of a mechanism by which you touch/ act upon one thing and the effect takes place upon something else. Go on, get your Rube Goldberg on.
Thanks for checking it out. I welcome any comments or suggestions.
I like it! Everyone wants a Toll Both Gun but they are prohibitively expensive. This one you can make for very little money.
The simplest entrant
So far we have seen entries that require some skill and a lot of work — except for the spaghetti shooter. Now we come to another entry that vies for the position of the simplest one. It’s called Smile from reader Fish.
Here is my entry to the AG Design Challenge. It’s called Smile. Shoots cotton swabs. Anybody can built it under $1.50. Fish.
It comes with no instructions, but it doesn’t really need them.
From the frozen north of Canada, reader Vana2 who is our friend Hank, sent us his stone crossbow that he calls the Stone X-Bow.
For the “Design an Airgun” contest for something that shoots I would like to submit a “Stone X-Bow” which as the name implies, is designed to shoot stones or better still, marbles or ball-bearings instead of bolts.
The Stone X-Bow is a modern interpretation of the ancient stonebow.
I have always loved anything that shoots a projectile and in my early teens designed and made a whole variety of weapons powered by elastics or bows. Slingshots were great but back then the bands (usually cut from bicycle inner tubes) were nowhere as good as the latex and surgical tubing bands used these days. Considering power and availability, bows were my power-plant of choice, the following is a prime example…
The overall Stone X-Bow design is straightforward and can pretty well be laid out on the fly. The main considerations are to have at least a 2.75 inch “window” between the bows and the bow supports (to clear the projectile) and to be sure that the pellet pouch is centered between the bows. The bow’s draw length determines the distance from the bow supports to the release mechanism. The rest of the stock can be penciled in to suit, with the only requirement being the shape of the grip for the trigger.
A variety of material can be used to make the bows. The bows for this project are cut from a fiberglass chain-link fence “tensioning bar”. Fiberglass rods used as driveway markers, or tent poles or chimney cleaning poles are suitable as well. Bamboo stakes also make a good bow, you just have to match up a pair and join them in the middle.
The Stone X-Bow is a fun project that is inexpensive to build and can be made with a couple of hours effort (spread over a day or two to allow for glue setting). They are consistent shooters and can be made powerful enough for small game hunting. In pursuit of “how big can you make it” I made a Stone X-Bow that would rival a potato cannon in power. It shot golf balls.
Hope you find this interesting enough to build your own.
To eliminate complex routing I laminate up the stock from six 6 inch wide, 1/4 inch thick pieces of plywood. Per the picture below, two pieces marked “A” are the outer laminates; “B” are the laminates that provide the clearance for the trigger block and “C” creates the slot for the trigger.
Quarter-inch laminations saved the problem of routing thick wood with precision.
Labeling all the pieces and pinning them together (with 2 inch finishing nails) keeps everything together and aligned for cutting and later registered for gluing.
I didn’t have any plywood available so I cut my 1/4” material from a 2×4 and added a piece of 2×6 for the butt of the stock. Not having the plywood was a bit inconvenient but it can be made to work without too much problem.
The trigger of the Stone X-Bow is a rolling block style similar to that found on many regular crossbows, the difference is that it has a single pin to capture the pouch rather than two pins to hold the string and bolt.
Trigger assembly detail.
The trigger sear.
The trigger has fired the bow.
Stone X-Bow from the top.
The trigger block is made from a piece of hardwood dowel and a bolt that is long enough to make the pin and has the head filed flat to make a sear. The trigger block is mounted with two screws that are supported by washers imbedded in the stock.
The trigger has another modified bolt and is positioned to engage the sear on the block. A spring is used to keep the sear and trigger engaged until the trigger is pressed. I used a 2-inch finishing nail for the trigger pivot point.
Hank has just given us the detailed plans for a stonebow. Only a little more work is needed to turn his design into a crossbow. This is not the simplest project by any means, but it is one of the best!
Hank is aware that he cannot win the prize that would be difficult to receive in his country. He just wanted to be in the contest to support the blog and all of you readers. Thanks, Hank!
A hard job
When I started this contest I didn’t anticipate there would be this many entrants or this many really good projects. What we have is a range of projects to appeal to skills of all levels. I believe that many of you 100,000+ registered readers, as well as the quarter-million or more around the world who just read the blog and haven’t registered, are going to get much more from this contest than from several of my reviews put together.
How did I judge the contest? It wasn’t easy. In the beginning I wanted to make each new entry the winner and all I had to do was decide which of their projects I liked the best. But as more entries were received, things became more difficult. But one rule probably superseded all the others, and that was rule 5 that said, “The winner would be the niftiest design that the most people could build.” That made it easier for me.
While all of these entrants deserve recognition, one of them stands apart, based on rule 5. The winner of the Design an Airgun contest and the recipient of the American Zimmerstutzen — providing he still lives in the U.S.A. — is reader minuteofsomething, whose spaghetti blowgun is the niftiest and simplest project I see.
I purposely have not informed him of this. He gets to learn about it with the rest of you, by reading this report. I do have his email address but I am asking him to contact me today.
He has a You Tube channel with many other interesting videos, and I will try to make that available to all of you, once we connect.
This contest has opened my old eyes about what interests many of you readers. I wish my late wife, Edith, had been here to see it, but I believe she may be following it anyway. My thanks to all of you readers for a most enjoyable time — Tom