Introduction: Gatling Rubber Band Machine Gun - Easy Weekend Project
Runner Up in the
Epilog Challenge VI
This super fun rubber band gatling gun project can be completed in a weekend with inexpensive material and basic tools that most people already have. There are easier ways to make some of these parts using expensive specialized tools, but we tried to make the entire guide more accessible by using basic available tools that anyone can use.
The plans and templates are available for FREE to download on this site, and the method shown in the videos and described in this instructable will make it easy (even for a novice wood worker) to complete this project and start slinging rubber in no time!
The gun can shoot LOTs of rubber bands, the only limiting factor to the number of rubber bands it can hold is how many rubber bands can physically fit on each barrel without slipping off. The limit is very high though, and should be ample ammo to dominate any rubber band gun fight!
There is a process to loading the rubber bands, and it's a little tricky at first, but by watching the video on how to load the rubber band gun, and practicing, you should be able to master the process in no time!
I enjoy making projects like this, and have used CNC machines and a laser cutter for similar projects, but access to those machines can be a problem (I only have access to the laser machine during school semesters). I am entering this into the EPILOG CHALLENGE VI contest (among others) and hope to win a personal laser machine to produce more fun projects like this one. If you like this project, PLEASE VOTE FOR ME!
Step 1: Required Tools
You will need the following tools to make this rubber band gatling gun:
- Hand Drill - We did this all with a hand drill, but if you have access to a drill press, it will probably be even easier (but not required).
- Drill Bits (1/4", 5/8" and 3/4") - You will use these with the above mentioned drill. For the most part we used Spade bits, but that is just because they are cheap and come in lots of different sizes. Also, if you have access to a hole saw bit for your drill, the 2" spacers and 4" barrel rotors would be much easier to cut out, but again, you don't need those specialized bits, we will show you how to do it without those.
- Jig Saw - This is to cut out the shapes of the gun parts, and we also used it to cut some of the dowels and other odds and ends. You could also use a scroll saw if you have access to that (it would probably be easier), but again it's not required, a simple jig saw will work fine (will want a nice wood fine cut blade for it to ensure the cleanest cuts).
- Wood glue - We just got a bottle of standard wood glue, nothing special required, just a good quality glue that will hold together and dry in a reasonable amount of time.
- Sand Paper - We just bought a pack of 200 grit sand paper, and we still had quite a few sheets left over after the project was finished. If you have access to disc sanders, electric sanders, radial sanders, or belt sanders it will save you some time, but if you have enough patience, hand sanding the pieces is not bad at all.
- Rubber Bands - As you will see in the video, I used rubber bands to hold the barrel together while I was gluing it together (I thought it was very fitting :). If you have an assortment of clamps and vices, they may make assembly easier, but they are definitely not required. If you're building a rubber band Gatling gun, chances are you have a few rubber bands lying around anyways :)
- Tooth picks - I use tooth picks to help apply the glue when assembling the gun, but they are just a personal preference. I like them because they are cheap and disposable, and we usually have them on hand. I squirt the glue onto a sheet of paper in a small pool, and then scoop it up with a tooth pick and smear it where it needs to go on the gun. It gives a good even coat and I have lots of control on how much glue I use and where it goes. I know some people prefer a paint brush or other applicators, those should work fine too.
- Glue stick - You need this to glue the templates to the pine board. Again, nothing fancy required, we use the generic white glue stick that comes in a pack of 3 for a buck. Didn't even use a whole glue stick either. Just has to glue the template down long enough to cut it out. We don't want the glue to be so sticky that we can't sand the paper and glue off of the pieces when we are done.
- Half Round File (OPTIONAL) - This is just a metal file that has a rounded side to it. This is not required, but it helps with some of the holes to make sure the dowels will spin freely in them. You could use sandpaper, it would just take a little longer, but if you already have a half round file, it may save you some time (When I checked my local hardware store, they had an 8" half round file for $7, probably not worth it just for this project, but if you were going to get one anyways, it's not a bad price to save some time).
- Hand Saw (OPTIONAL) - I found the hand saw came in handy a few times when I was making quick cuts and adjustments to the dowels. You could easily do the same cuts with a jig saw though, so this is very optional.
Step 2: List of Materials
The materials you will need to construct this Gatling gun are:
- 4 x 5/8" Dowels - These will serve as the barrels, but also as the barrel shaft and the crank shaft and handle. I bought 4 48" long poplar dowels. The material isn't that important, poplar is just what my hardware store had in stock. They cost about $2.50 each. Some craft stores may have different material and cheaper ones, but I was happy to use poplar (I like poplar, it's pretty easy to work with and pretty cheap, a nice balance).
- 1 x 1/4" Dowel - We only need this for the rear barrel rotor. They go against the main barrels (sticking out a bit) to stop the rubber bands from slipping down and around the back of the barrels. The one we bought was 48" long, and we had a ton left over, if you can get a shorter and cheaper one, you would be fine.
- ~15 feet of nylon kite string - I didn't actually measure 15 feet out, I just wrapped it around my arm 13 - 15 times, and that was plenty. The string will go under the rubber bands as you load them on, and then as you wind the string back up, it pulls each rubber band off of the barrel to shoot each individual rubber band off. Making the string longer could potentially allow for more rubber bands to be loaded onto the barrel, but you will run out of room on the barrels before you run out of string. It doesn't technically need to be nylon, I just like the nylon stuff because it wears great and it's easy to burn the ends with a lighter to stop it from unraveling.
- 1 x 3/4" Pine Board (1 x 24 x 8 ish) - We use pine for a number of reasons. First of all, it's cheap and widely available. Second, it's a very soft wood, which makes cutting, drilling, and sanding it very easy.
NOTE: When buying wood like this, it will be listed at the hardware store as 1" thick, but it will actually be 3/4" thick. From what I understand, this is because the boards start out 1" thick, but then an 1/8" gets planed off each side to get it ready for retail, I could be wrong on that though, the moral of the story is to look for the stuff labeled 1" thick, but grab a tape measure if you're worried it's not the actual 3/4" thick you need.
NOTE 2: When looking at size, just realize you will need a big enough piece for all of the templates. It would probably be wise to print the templates out and take them with you. The largest piece you will need is the gun stock, and as you can see in the video, I had to lay the template sort of diagonal to fit on my piece of pine. Each hardware store may have slightly different dimensions so it is tough to give an exact one to look for, but by taking the printed templates with you, you should be able to find a nice suitable piece. Also, make sure there aren't too many knots or gouges in your piece. The knots can be tough to cut/drill through, and they can also break out making the piece unusable.
Step 3: Printing the Templates
The template files are in PDF format, so you may need to get adobe reader (http://get.adobe.com/reader/) to view them. Download them from this site and then make sure when you print them out that you click the option that says "Actual Size" under "Page Sizing and Handling". This ensures that the documents prints at 100%, otherwise the templates will not work.
There is a ruler printed at the bottom of every template page, this is so that you can use a measuring tape or ruler that you already own to verify that the templates printed at 100%. It is worth double checking this before you glue them to the wood and cut them out.
Once you have printed all of the templates and verified their size with a ruler, you're ready to cut them out and glue them to your pine board. Don't trim them too close to the edge, leave plenty of paper to glue down so that it is held firmly in place while drilling and cutting. I actually printed 2 sets of templates just in case anything happened while cutting out the wood, I would have another set of templates ready to trim and glue.
Step 4: Gluing Templates
After you have all of the templates printed out and you have verified the print size with a ruler or measuring tape, you're ready to glue the templates onto the wood. Take each template sheet and cut out the gun parts (leaving an inch or 2 of space around the edge).
Take each cut out template, and cover the back of each with your glue stick. Try to get as much of the paper covered, right up to the edges of the paper. It will make it much easier to cut the wood if your template is firmly attached to the wood.
Now press each template onto the wood, smoothing it as you go. After each one is glued in place, let it set for a few minutes to assure proper adhesion to the wood surface. It doesn't take long for the glue stick to dry, so just a few minutes is sufficient.
You're now ready to start drilling.
Step 5: Drilling
It is best to do all of the drilling first. Each of the holes in the template is marked with the size of drill bit you will need to use. We used Spade Bits as they are cheap and widely available, and they do a decent job. More expensive helical drill bits will probably make a cleaner cut, but they are much more expensive (especially for the larger 5/8" and 3/4" bits).
Each of the holes on the template that are marked for drilling will also have a center dot marked to help you know where to place the drill bit to start. Just place the tip of the drill bit in the center marked hole, and try to make sure you have the drill as straight up and down as you can. If you have access to a drill press, this will be much easier, but not required. As long as you are careful, you will be able to get evenly spaced clean cuts.
For the most part, it does not matter what drill bit you start with. The only real exception is for the rear barrel rotor. It is easier to drill the 1/4" holes first, and then drill the 5/8" after (if you do it the other way around, the smaller drill bit will want to slip into the larger hole while cutting).
It also helps to have a "sacrificial" board to place underneath the pine board when drilling. You can drill right through the pine and into the bottom board, this will help make cleaner cuts (otherwise the pine will have a tendency to have ragged exit holes as the bit breaks out the bottom when drilling).
Once you have drilled out all of the holes, you will be ready to start cutting.
Step 6: Cutting
This is probably the trickiest part off the project. We used a Jig saw in the video, but if you have access to a scroll saw, that would probably be much easier, but as you can see from the video, it's very doable with the Jig Saw.
Gun Stock - For this, you're going to have to just cut it from many different angles, taking out pieces and nibbling away tight corner pieces until you can fit your blade to make straight cuts. I also didn't bother worrying about the rounded off corners on the back of the butt, those were easy to do with a sheet of sand paper when I was all finished. If you're having a difficult time with any of the areas, just make sure and try to cut "proud" of the line (i.e. err on the side of too much material instead of cutting into the lines). It's always possible to sand and cut material away, it's pretty hard to add it back on.
Rotor Barrels - These just need to be cut from drilled hole to drilled hole. Do your best to follow the arch with your saw blade, but you can always sand it smooth after.
String Guides - I started with the inside cuts (where the guide pieces will attach to the gun stock). You should already have a 3/4" hole drilled here to make it easier to fit your blade into these tight corners. Then just cut along the outside line until the piece is cut out.
NOTE: The guides I cut in the video ended up being harder to cut than I thought they would be (the shape had more tight rounded corners). Since this was such a hassle to cut out, I updated the template files to make these parts much easier to cut out (and they will function exactly the same way).
Hand Crank - Just need to cut this piece out the best you can following the curves with your saw blade. I just tried to stay on the outside of the line and then I sanded it down to the final shape.
Barrel and Hand Crank Spacers - All of the spacers are the same size, so these can all be done at the same time if you need. These were a little tough to cut out, but not impossible. Again, I just followed the line, and made sure to stay on the outside of it so that I could finish it with sand paper.
NOTE: All of the spacers are 2" diameter circles. If you have access to a 2" hole saw, this would make cutting these out much easier. This is not required though, and is only suggested if you already have access to the hole saw for your drill.
Step 7: Barrel Dowels
This gun is designed to use 10 5/8" diameter dowels for the barrels. We bought our dowels in 48" lengths from the hardware store, and we used 3 rods (with some left over). I have also seen dowels sold in 36" lengths, so make sure you have enough dowels for the size you buy.
Each barrel will have a curved edge and a flat edge. The curved edge will point forward on the gun, and the notch is to hold the rubber bands in place. The flat edge will sit in the rear of the gun, and needs to be flat to allow the rubber bands to be pulled up and over the back of the barrel to launch off when spinning the hand crank. The 1/4" dowel pieces will rest against the rear flat barrels to make sure the rubber bands don't slip under the rear of the barrel (which again would restrict the rubber band from launching off of the barrel when the hand crank is spun).
To make the front notch in the barrel, we used a 1/2" spade bit (again, a helical drill bit would work if you have it). We drilled the 1/2" hole into the dowel trying to make sure we were as close to the center of the dowel as possible. Once the hole is drilled in, we just cut the dowel at the center of the drilled hole (so that you end up with 2 pieces of dowel that have half circles cut out of one end).
We chose 12" is our barrel length. We felt this was a good length with many rubber bands available in that size range. If you want a longer or shorter barrel, now is the time to decide. We measured from the half circle end and marked 12" on each dowel. We then used the Jig saw to cut them to length. We repeated these steps until we had 10 separate barrels.
While we were cutting the barrels, we also cut out the 1/4" dowels that will work as the stopper for the rear barrel rubber bands. The length of these can depend on how you assemble your gun, but we chose 1.5". Make sure and cut out 10 of them (one for each barrel).
Also, note in the picture of the assembled barrel rotor assembly the orientation of the barrels. You will need to make sure you twist them to the correct angle when gluing the assembly together.
Step 8: Rotor Axel Dowel
The rotor axel is the part that attaches to the gun stock and allows the barrel rotors to rotate. We used the same 5/8" dowel material, but we just cut it with the Jig saw to about 15" - 16". You want a bit more than you will actually use, and then just trim the rest away during assembly. Measure and mark the dowel, and cut it at your mark.
You will also have to drill a hole into the gun stock that the rotor axel will be glued into. This is probably the trickiest drilling you will have to do. It's important to get this as straight as possible, and to try not to have the drill bit blow out the side of the stock. Basically just eye ball the center of the gun stock and drill about 1/2" into the stock with a 5/8" spade bit. Go slow and you'll be fine.
Step 9: Hand Crank Dowels
There are two dowels used by the hand crank. The one that will work as the axel that spins in the gun stock, and the one that will actually be used by your hand to wind the crank. We cut the axel portion about 6" (not less) knowing that we would have to cut it down during assembly. As for the hand crank, I just held the dowel in my hand, and marked the size based off of how wide my hand was. Both of these can be trimmed later if they are too long.
Step 10: Sanding
I didn't bother capturing any of the sanding on the video since it's pretty standard stuff. I started by sanding all of the template paper and glue off of the pieces. Didn't take too long since it was only a glue stick. After I had that cleaned off, I just sanded any parts that needed it. I was looking for any rough patches, areas that didn't get cut with the jig saw, or any corners that I decided would be easier to sand. It's a little time consuming, but it's not horrible. The pine is so soft so sanding goes pretty fast.
If you have a half round metal file, that can help in a few places now too, but it's not required. I also took a little time to round some of the edges (especially around the handle). I just wanted to make it a little nicer to hold and it also looks better I think. I just rubbed some of the sand paper over the sharp edges until it was rounded to my liking.
With all of your sanding, start with a lower number grit like 100, and then work your way up to finer grits like 280. You can go crazy and get really high grit paper, but I don't think it's needed for this type of project.
Step 11: Assembly
Really, it will be best to watch the video for this. I will try to explain some of the tricker parts, but it is pretty straight forward if you watch the video.
I used a good quality wood glue, and I just squirted some out on a sheet of paper. I then took a tooth pick and scooped a little glue up and smeared it on the pieces I wanted to glue together. Then I just glued them together.
I didn't use any fancy clamps (but you could if you have them), the fanciest I got was some rubber bands to hold the barrels in place while they dried, the rest was just gravity.
Vertical String Guide - I started with the gun stock and the string guides. The vertical string guide goes right up against the front of the stock. It also helps to strengthen the area since you had to drill out the hole in the stock for the rotor axel. Once this is glued in place, it should bring a lot of strength to that area.
Horizontal String Guide - In the video, I glued the horizontal string guide right up against the vertical string guide. I wish I had put some space in between these 2 parts though. It still works on mine, but I can see it would have worked better if the horizontal guide was placed farther back toward the angle on the stock.
NOTE: This is also where you can make this either a right hand or left hand rubber band gun. But choosing which side the horizontal string guide will feed the string to, will determine if you wind the crank with your right or left hand. I am right handed so I placed the horizontal string guide hole on the right side of the gun stock.
Barrel Axel - Next I took the barrel axel, rolled the end in a bit of glue, and then put it in the hole of the gun stock. I tried to make sure it was sitting as straight as possible before I found a place I could lay it where it wouldn't be disturbed as the glue dried.
Hand Crank - Next I glued the 2 dowels into the hand crank piece. I needed that dried before I could glue the assembly to the gun stock. Just eye ball it and get them as close to straight as possible. Make sure and put the axel in the hole at the larger end, and the hand crank at the hole in the smaller end. I marked my dowels with pencil after I cut them to make identifying them later easier.
Barrel Rotor Assembly - I used rubber bands to hold this together, then I put glue into the front end and let it dry. It is easier to see in the video how to do this, it's much more difficult to explain. Don't glue the rear rotor (the one with the 1/4" holes in it) as you will need to space this once more of the gun is assembled and then glue it. Again, this is shown in the video more clearly.
LET ALL OF THESE PARTS DRY AND SET FOR AN HOUR OR TWO
Barrel Axel Spacers - For this part I placed the barrel axel spacer on the axel, then I placed the half glued barrel rotor assembly on and I just used business cards in between the spacer and the gun stock until I could safely spin the barrel rotor assembly without the 1/4" dowels hitting the string guides (I hadn't glued the 1/4" dowels in place yet, I just placed a few in there to size it up). For me, the magic number was 8 business cards, but this can change depending on how you assembled the first parts of your gun. Again, if you watch the video, you will see how I did this with business cards. Once I had the space figured out, I just put a bit of glue on the spacer and set it aside to dry.
Rear Barrel Rotor - Now that I had the spacing figured out for the barrel rotor and spacers, I was able to glue the rear rotor in place. Just like the front rotor, I leave the rubber bands on and just separate the barrels from the rotor enough to slip a little glue in between them.
1/4" Dowels - I just rolled the ends of the 1/4" dowels in glue, and stuck them in each hole. These need to lay flat against the barrel (any space between these will allow the rubber band to slide under and behind the barrel and will cause mis fires). If the dowels were fitting right up against the barrel, I just used a rubber band around the 1/4" dowel and the barrel to make sure it dried making contact.
Hand Crank - Next I finished the hand crank. I put a spacer on the axel, then pushed it through the gun stock, and put another spacer on the other side. I moved the axel in and out until I found the proper length where the hand crank wouldn't hit the string guides when winding. Once I found that spot, I marked it on the axel with a pen, and then I cut it where I marked it. Then I got my business cards out again, and put a few cards in between the spacers and the gun stock on both sides. There just needs to be enough space so that the crank can move without being pinched against the gun stock. I did 4 cards on each side, but that's probably a bit much, 2 would have been enough and it would have made less wobble, but 4 worked ok still. Then I just put a little glue in on the spacers to get them secured, and set it aside to dry.
NOTE: If you have chosen a left handed configuration, you will need to make sure the hand crank is placed on the same side as the string hole from your horizontal string guide.
Barrel Rotor Assembly End Spacer - Next I finished off the barrel rotor assembly by using the business cards to space them, and then glue them in place. I had to cut my business cards to fit into the smaller place. Again, it just has to have enough space between the rotors and spacers so that the assembly can spin freely. I used 4 cards, but 2 would probably be sufficient and create less wobble. Once cards in the back and front of the barrel, I glued the end spacer in place.
After that, just let all of your glue dry and you're ready to add the string.
String - Take one end of your string and thread it into the rear barrel rotor, tying a knot of the inside of the barrel assembly so the string can't pull back through. Then thread the string through the vertical string guide and the horizontal string guide, and finally wrap it around the hand crank axel and tie it in a knot around the axel. Apply a bit of tension on the line, simply wind the string up with the hand crank until you have all of the string wound around the axel. You're all done and ready to load your gun and start shootin' pardner!
Step 12: Loading Your Gatling Rubber Band Machine Gun
It's much easier to see how to load the gun by watching the above video.
The basic idea is that you place the string over the barrel first, then stretch a rubber band over top of the string. Rotate the barrel one over, and repeat the whole process. You keep going round and round the barrel until there is no room left on the barrel for any more rubber bands. As long as you place only one rubber band over each layer of string, you can keep going around the barrels and load multiple rubber bands per barrel. They will shoot off of the barrel one at a time as you wind the string back up.
I hope you have enjoyed this project, it's a blast to make and super fun to use!
Step 13: Finished Gun Pictures
Here are some pictures of the finished Gatling rubber band gun. If there are any parts you want better pictures of, let me know and I'll update this section with more detailed pictures of the final gun.
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