# Shooting Circular Saw Blades With The Slingshot?



## JoergS

I am thinking about making a slingshot rifle that shoots circular saw blades. I ordered some today, 6 inches diameter. Shouldn't be too heavy.

I want to use a wooden axis that goes through the sawblade's center hole and that I can lock into the trigger mechanism. I want to have a little slotted rail that guides the top of the blade on the first few inches of the flight, and gives just enough friction to make the blade rotating. A bit like a hop up for soft air guns.

On the one hand this sounds scary and dangerous, but I think if I construct it right and build it well, it should work.

What do you guys think?

EDIT: Here it is!


----------



## PandaMan

I think you're absolutely crazy! But in a good way I guess.
I can see your design working safely. Wear full welding gear for protection though!


----------



## huey224

this will top your machete slingshot! 
it you construct it right it will be able to penetrate car doors, i have seen people throwing them and the stick into old cars!


----------



## mckee

This will be awsome!


----------



## radray

Joerg,

You are like a kid with his toys. You gotta love that. I like the idea and curious to see how you will execute it my friend. Good luck with that.

Another kid and his toys.
Raymond


----------



## Hrawk

Perhaps you can get some ideas from this:

http://www.dansdata.com/shotblade.htm


----------



## AJT

As soon as I saw the title of the thread, I knew who was behind it lol. That is one crazy idea, though aren't all your ideas a little like that anyway??









Go for it!!

AJ


----------



## Dayhiker

If it were anybody else, I'd probably say, "whoa!" But I have come to realize that you have the engineering skills to pull this off safely. Go for it Joerg!


----------



## M.J

JoergS said:


> On the one hand this sounds scary and dangerous, but I think if I construct it right and build it well, it should work.
> 
> What do you guys think?


I think it sounds scary and dangerous!
But I'm sure you will construct it right and build it well and it will work.
Should be an all-time classic video!


----------



## Hit and run

If you spin it separately you wont loose energy to make it spin when you launch it, so more speed. Perhaps a 2 stage launch. You could wrap some elastic around the axle?

Anyway, just an idea.

hf.


----------



## NightKnight

I cannot wait to see it!


----------



## Imperial

i can see you building this. maybe if its built similar to the machines they use for skeet shooting. or to flip it like the throwers you see for the clay targets. saw blades curve a lot in flight though. they dont exactly fly like a frisbee. so dont be surprised if after a few feet they take a huge turn and then keep rolling for a good distance.


----------



## philly

At first I thought you were writing about your destruction of the saw blades at the ECST bent by your cannon ball size shot. Sounds like something from a horror flick. Only you can pull it off Joerg. I don't think you will be able to get it through customs for the next shoot in Alverton though







. Be safe, can't wait to see the video.
Philly


----------



## dgui

There can be no doubt.


----------



## Ace

Jorg you are taking it to a WHOLE NOTHER LEVEL.............. AND I'M LOVIN' IT!!


----------



## TastelikeSnozberries

I wouldn't want to be the first to shoot it, but I can't wait to see the results! you've revolutionized the sport, and demonstrated proper safety the whole time, I have no doubt your creation will be absolutely epic


----------



## JoergS

TastelikeSnozberries said:


> I wouldn't want to be the first to shoot it


The first shot with a new weapon is always a bit high on the adrenaline side.









Especially when the ammo of choice is sharp and generally dangerous...

I will make a "dummy" blade that is very dull, and wear a motorbike helmet plus protective clothes.

Of course then nothing will happen. Precautions always turn out not needed in case you take them! Which does not mean that you can skip them, unfortunately...


----------



## Bert

Joerg, I would not like to get on the wrong side of you! What's your engineering background?


----------



## JoergS

Bert said:


> What's your engineering background?


I don't have one. I have a master in business administration and have been a manager all my life. Picked up some mechanical skills with the "learning by doing" method.

Jörg


----------



## Hrawk

I reckon it's going to turn out something like this:


----------



## JoergS

Hrawk said:


> I reckon it's going to turn out something like this:


Great pics, and yes, this is about how it will look like.

The guide rails will only guide the top part, and only for a few inches, though - the friction is supposed to add spin to the blade, and for the rest of the flight, my experience is that it is best to have nothing solid in the way of the projectile. Free flight is best. More power and accuracy.


----------



## Hrawk

I was just thinking, with the design I drew, if you were to glue a strip of rubber (TB gold etc) to the top of the bottom rail, it would impart spin the whole length of the rails. Even expand on this with a thin delrin strip on the underside of the top rail.

Were you perhaps watching day of the triffids when you came up with this idea ?


----------



## JoergS

The friction would slow the blade down very much. The contact with the rail has to be very brief. Don't forget that the power in a slingshot band is very limited at best.

Have never heard of that show! If it contains saw blade shooting, I want to buy all of its episodes on DVD...


----------



## Hrawk

Here's what I expect of your gun when it's finished:






It's the original BBC Day of The Triffids TV series. One of the chatacters has a rifle/gun that shoots 4-5" circular saw blades. He uses it to decapitate the Triffids.

I'll see if I can find a link for you.


----------



## CRO-josip14

nice vid but its impossible..=)


----------



## Gwilym

I agree but would like to know how its done. I love day of the triffids they are in the book as well but they work from a spring I think. I would assume they would be in the new tv thing as well as they feature pretty heavily in the book.


----------



## JoergS

Saw blades arrived, heavy, sharp things. They weigh 168 gramms (6 ounces). That is really heavy, so I have to use quite a bit of rubber to make them fly fast. Not a problem, the way how I designed this you attach one side first, then the other side.

I think I can get them to fly at about 50 m/s, 164 fps or 180 km/h, 112 mph.

Jörg


----------



## Nico

JoergS said:


> Saw blades arrived, heavy, sharp things. They weigh 168 gramms (6 ounces). That is really heavy, so I have to use quite a bit of rubber to make them fly fast. Not a problem, the way how I designed this you attach one side first, then the other side.
> 
> I think I can get them to fly at about 50 m/s, 164 fps or 180 km/h, 112 mph.
> 
> Jörg


Make a video slaugtering some giant plant matter like watermelons or something similar..

Sounds like a very scary weapon either way..

Nico


----------



## shawnr5

You rock. I can't wait to show my coworkers the video. Do it as safely as possible. As cool as it looks, it's not worth seriously injuring yourself.


----------



## ZDP-189

If anyone can (or would want to) do it Jörg would be the man. I reckon spin trumps velocity.


----------



## JoergS

Did some throwing tests, and yes, rotation is a must. To be specific, the blade must be thrown vertically with a back spin to fly straight and far.

If you throw it like a frisbee, it drifts off to the side and down after a short distance.

If you throw it with a foreward spin, the flight is very short...


----------



## Hrawk

How are your soldering skills Jeorg ?
Two small electric motors (or two big ones if you want to be really evil







), put pulleys on them with o-rings on the pulleys. Mount one each side of the blade so they are just touching the blade. Add batteries and a switch.

Load, aim, flick the power on to the motors, get the revs up, pull trigger, destroy!

You could probably get most of the parts you would need from a cheap RC car or an old cordless drill, including batteries and chargers. Nah, go for an RC car, then you can use the radio gear and servos for remote firing, YEAH!



Gwilym said:


> I agree but would like to know how its done.


Yarr, it's fake.

IIRC Timber was cut to with a papers thickness left on the visible two sides to the camera. The throw was real enough, he just had to hit it close to the weak spot. The sawdust and saw sound were probably added in something like after effects.

There's about 5 or 6 of these videos about, one painting pictures with a nail gun and another with retractable tape measures opening doors and turning off light switches.


----------



## JoergS

I am a bit afraid about very fast rotations. It could lead to an unpredictable flight, possibly coming back to the shooter (that would be me).

To stabilize the flight, very fast rotations aren't needed. When I throw them, one rotation every five meters is all I need to get a stable flight. I think I can do that without motors.


----------



## dgui

Hrawk said:


> Here's what I expect of your gun when it's finished:
> 
> 
> 
> 
> 
> 
> It's the original BBC Day of The Triffids TV series. One of the chatacters has a rifle/gun that shoots 4-5" circular saw blades. He uses it to decapitate the Triffids.
> 
> I'll see if I can find a link for you.


He put a deep saw kerf in it first underneath it leaving 1/8th inch wood on top just enough to hold the light weight spruce 2 by 4. But he did manage to hit the two by with the 7-1/4 inch saw blade. A nice hit and a nice lie.


----------



## Aras

Wooow, when it is finished, go to the forest and cut naturals from trees


----------



## PandaMan

JoergS said:


> Saw blades arrived, heavy, sharp things. They weigh 168 gramms (6 ounces). That is really heavy, so I have to use quite a bit of rubber to make them fly fast. Not a problem, the way how I designed this you attach one side first, then the other side.
> 
> I think I can get them to fly at about 50 m/s, 164 fps or 180 km/h, 112 mph.
> 
> Jörg


If your prediction is correct, that will have 154.90 ft/lbs (210J) of energy and will have sharpness and spin on its side as well! This will be some weapon!









You could make a meal just with your slingshots I reckon. Tenderise some meat with steel balls, cut up said meat and some vegetables with this fine contraption, then simply launch a molotov over the top and it's done! And it's all cooked in alcohol as well!









One more thing! If you added a scope to this, and zeroed it at, say 15 yards it would be the most awesome weapon in existence. I certainly, honestly, can't think of anything cooler than this!


----------



## JoergS

Before I make a scope mount and other fancy accessories, I have to make a very simple and raw test crossbow. Once I know that it is

- safe
- accurate
- effective
- manageable

I see no point in optimizing it any further before these issues have been solved.

Jörg


----------



## PandaMan

Good point...


----------



## Rayshot

dgui said:


> Here's what I expect of your gun when it's finished:
> 
> 
> 
> 
> 
> 
> It's the original BBC Day of The Triffids TV series. One of the chatacters has a rifle/gun that shoots 4-5" circular saw blades. He uses it to decapitate the Triffids.
> 
> I'll see if I can find a link for you.


He put a deep saw kerf in it first underneath it leaving 1/8th inch wood on top just enough to hold the light weight spruce 2 by 4. But he did manage to hit the two by with the 7-1/4 inch saw blade. A nice hit and a nice lie.
[/quote]
Yeah, I like the way the board is still shooting saw dust after the blade is well past. And the buzzing sound.


----------



## Ted

How about cutting a short piece (say 1 1/8" long) of wooden dowel that is just slightly smaller in diameter than the hole in the center of the saw blade. Now glue rubber (e.g. TheraBand) around the dowel piece so this short cylinder of dowel is covered with rubber over its entire curved surface. So we have a rubberized dowel now. Then carefully work the dowel into the hole in the center of the saw blade so about 1/2" of the rubberized dowel sticks out on each side of the saw blade. The diameter of the dowel and the thickness of the rubber glued to it has to be just right so when you rotate the dowel around its axis, it will make the saw blade rotate along with the dowel. Now if the dowel can be made to roll down the entire length of the slingshot rifle barrel then it will be forcing the saw blade to rotate the entire length of the barrel, not just a few inches of rotation at the beginning when the trigger is pulled. Maybe this will result in the saw blade rotating faster when it leaves the rifle.

To make the dowel rotate down the entire length of the barrel, cut two more short pieces of dowel (say 1" long each) and place one on each end of the rubberized dowel. These two short pieces of dowel are left entirely wood - no rubber glued on to them. The slingshot bands will wrap around these two wood-only dowels and pull them the full length of the barrel, with one wood-only dowel on each side (left and right) of the barrel. Then we need a metal pin of some sort that will connect the two wood-only dowels to the rubberized dowel so that all 3 dowels are positioned along a common axis. Drill holes along the dowel axes in all 3 dowels and put the pins in those holes. Glue the pins into the holes of the wood-only dowel, but do not glue the pins into the holes of the rubberized dowel. The wood-only dowels do not rotate along their axes as they are pulled down the barrel length. But they pull the rubberized dowel with them because they are connected by the pins. And the pins allow the rubberized dowel to rotate while the wood-only dowels do not. Maybe put some soap in the inside of the holes of the rubberized dowel so it can spin more easily.

Now we need a way to pull the wood-only dowels away from the rubberized dowel as the saw blade gets close to the end of the rifle barrel. When the saw blade flies away from the rifle, we want the wood-only dowels and the pins to stay with the rifle while the rubberized dowel goes with the saw blade. There could be some channel that the wood-only dowels ride in that starts with the two wood-only dowels say 1 1/4" apart when the saw blade is first loaded into the rifle and ready to shoot, but widens to 2" or so by the time the saw blade has reached the end of the barrel and is ready to start flying. Depends on how long the pins are. The pins are free to move in and out of holes drilled into the rubberized dowel. So when the wood-only dowels get pulled apart at the end of the barrel, they pull the pins out of the rubberized dowel, and the rubberized dowel with the rotating sawblade attached to it flies off to the target.

Since the channels that the wood-only dowels ride in are not parallel but are at an angle of maybe a few degrees relative to each other (1 1/4" apart at one end, 2" apart at the other), the wood-only dowels would need to be cut at the same few degrees off of 90 degrees so that they can ride smoothly in the channels but still have a common axis with the rubberized dowel. Maybe it's better to use square cross-section pieces of wood instead of round dowels for the two wood-only pieces.

Possible problems: (1) These small wooden dowels cannot stand that much force and will split apart when the slingshot is fired. Metal dowels would work better but are harder to make. (2) Suppose the metal pins do not exit the holes in the rubberized dowel at exactly the same moment. This may cause the saw blade to twist as it leaves the rifle. May need some precision machining here. (3) The "hand-tight" fit between the rubberized dowel and the saw blade would slip due to inertia of the saw blade when the slingshot is fired, and the rotating rubberized dowel won't actually rotate the saw blade that much. May need a way for the rubberized dowel to grip the saw blade more firmly. Maybe grip the saw blade on the sides of the saw blade right around the center hole of the blade, instead of just on the inside surface of that center hole? (4) This design spins the saw blade in one direction. I don't know if that's "forward" or "backward" spin. If only backward spin works for the flight of the saw blade, then this design may be completely opposite what we want. (5) The friction of the rubberized dowel against the barrel for the entire length of the barrel may slow it down too much. Maybe overcome this with stronger slingshot bands?

Sorry for the long description - it's hard to put it into words. It would be fun to see how this works! But pretty dangerous to try out. Need to fire the thing from behind the Mythbuster plexiglass shield.


----------



## JoergS

Ted said:


> When the saw blade flies away from the rifle, we want the wood-only dowels and the pins to stay with the rifle while the rubberized dowel goes with the saw blade.


That is the problem I see with your idea. Things that "stay with the rifle" have a lot of energy stored, which means they have to be decellerated without breakage.

Wooden dowels at 180 feet per second will break on impact when hitting pretty much any surface. Metal is worse as the dowels will be heavier.

I experimented with crazy constructions a lot, and here are two facts that I found to be true every time:

1. Never attach things to the rubber bands. Even the pouches have to be as small and lightweight as possible.

2. Never let things touch moving parts. Give your bands and projectiles as much free flight as at all possible. Otherwise the friction will take a way a lot of power and make the shot unpredictable.

Jörg


----------



## Ted

Hmmm...then the wood-only dowels need to fly away with the rubberized dowel and the saw blade. If the hole drilled through the rubberized dowel goes all the way through, and the metal pin is long enough to extend from one wood-only dowel, through the rubberized dowel, into the other wood-only dowel, and is glued into place in both wood-only dowels with a tiny bit of space between the 3 dowels, then we can still get the rotation of the saw blade while the wood-only dowels are not rotating. I think this will take care of #1. But maybe not #2 since there is still friction between the rubber on the rubberized dowel and the frame of the rifle as the bands contract.


----------



## SlingMan

JoergS said:


> When the saw blade flies away from the rifle, we want the wood-only dowels and the pins to stay with the rifle while the rubberized dowel goes with the saw blade.


That is the problem I see with your idea. Things that "stay with the rifle" have a lot of energy stored, which means they have to be decellerated without breakage.

Wooden dowels at 180 feet per second will break on impact when hitting pretty much any surface. Metal is worse as the dowels will be heavier.

I experimented with crazy constructions a lot, and here are two facts that I found to be true every time:

1. Never attach things to the rubber bands. Even the pouches have to be as small and lightweight as possible.

2. Never let things touch moving parts. Give your bands and projectiles as much free flight as at all possible. Otherwise the friction will take a way a lot of power and make the shot unpredictable.

Jörg
[/quote]

Jorg,


I've noticed you seem to always find problems with others ideas. It seems part of being a genius as yourself
is to think solely on your own.


You're very consistent about discarding others input and only going with your own.


Just an observation, nothing personal.


Interesting...


----------



## JoergS

Do you see it that way? Hmmm.

I have in fact picked up many ideas from others and have given several people credit over the years. The gloveshot, the flechette shooters, Warhammer for the rotational speed slingshot "trebuchet", Bill Herriman for the "W" design, and lots more.

I really try to read everything people suggest to me, and often I don't fully understand what they are trying to explain. That may be the case because English is not my first language.

But I also tried a million different things, and have significant experience. Quite often I have to discard input from others as I have already tried that in the past and it did not work.

Jörg


----------



## Ted

I think the idea of a circular saw slingshot is outrageous and interesting and fun to think about designing. Jorg, you are taking it a step further and actually creating one! I for one am looking forward to the test results.


----------



## JoergS

OK, here is the shootable, but unfinished weapon. Besides the stock and trigger details, the friction bar for adding the spin is missing.

Note the solid fork construction! This is shooting super strong bands.


----------



## NightKnight

Impressive!! I wouldn't want to be on the wrong end of that thing!


----------



## Rayshot

JoergS said:


> I am thinking about making a slingshot rifle that shoots circular saw blades. I ordered some today, 6 inches diameter. Shouldn't be too heavy.
> 
> I want to use a wooden axis that goes through the sawblade's center hole and that I can lock into the trigger mechanism. I want to have a little slotted rail that guides the top of the blade on the first few inches of the flight, and gives just enough friction to make the blade rotating. A bit like a hop up for soft air guns.
> 
> On the one hand this sounds scary and dangerous, but I think if I construct it right and build it well, it should work.
> 
> What do you guys think?


I am quite interested to see the firing of this.

The only thing that makes my stomach get a funny feeling is that the extremely big and flat blade is being pulled from both sides of the blade, of what I see. Unlike the machete that was being pulled from a single pull point and thus directed in proper alignment and path of flight. It would appear susceptible to any unevenness of pull from one band or the other or split second release differential of the hold and release mechanism. Whereas things of flat shape are typically given their "fling" from a point more along the edge.

You no doubt thought of this so that is why I am interested to see it completed and fired.


----------



## SlingMan

JoergS said:


> Do you see it that way? Hmmm.
> 
> I have in fact picked up many ideas from others and have given several people credit over the years. The gloveshot, the flechette shooters, Warhammer for the rotational speed slingshot "trebuchet", Bill Herriman for the "W" design, and lots more.
> 
> I really try to read everything people suggest to me, and often I don't fully understand what they are trying to explain. That may be the case because English is not my first language.
> 
> But I also tried a million different things, and have significant experience. Quite often I have to discard input from others as I have already tried that in the past and it did not work.
> 
> Jörg


Thanks for the response Jorg!


I better understand now.


You're still a genius in my opinion!!!


----------



## Rayshot

Jorg,

You mentioned testing the slingsaw with a test disc. What would be very engaging to watch would be any video footage of test shots up to a shot(s) from a completed model. I don't know if you have done something like that except the crafting of a slingshot video. From what videos I have done I know this would mean extra work setting up the cameras to capture test shots, but tests to finale would be great.

Hopefully you will find this idea worthwhile. Even if there are missfires. Seeing them corrected/overcome if needed, would be interesting too.

Thanks for all your time, efforts and sharing.

Ray


----------



## JoergS

Ray, great idea. I have in fact bought a GoPro camera some time ago that has a really wide angle and comes with an undestructable action case. These cams are used for helmet mounts and so on. Great image quality for the money (250 $).

This camera is pretty much ideal for the task. I can't have my camerawoman around when I do test shots, for obvious reasons. But I can have the GoPro camera sitting on the roof of my truck when I test fire.

Jörg


----------



## Rayshot

Alright Jorg!

Not only did you get a cam to accommodate your videoing but you may get to share some behind the scenes footage, I am sure many will very much enjoy.

You da man!

Ray


----------



## JoergS

Here it is!

Did something wrong with the GoPro so the video of the test shots wasn't recorded. But I added two slomo studies from the test phase that show how pathetic this shoots without rotation.


----------



## mckee

brilliant!


----------



## PandaMan

LOL just when I thought the flechette slingbow was the best, you made this! Well done Jörg!


----------



## Brooklyn00003

Cool .
On the video you are using tubes and here in picture you are showing TG what happened?

Now let's see it in action.


----------



## JoergS

The flatbands got nicked during the tests (when the blade tumbled). I had some tubes lying around, they do a good job throwing the heavy blade.


----------



## Hairu

terrifyingly beautiful


----------



## JoergS

Not sure if you guys noticed, but this is the fourth vid of mine in a row that is going viral. Almost 100,000 views (and counting) after two days! Quite the record.

I sure hope this will drive more members to this forum.

I have to up the ante again, not easy.

Jörg


----------



## TastelikeSnozberries

I'm not sure if it's legal in Germany, but upping the ante doesn't get too much more legally upped than Tannerite,

http://www.tannerite.com/


----------



## NoSugarRob

cat + grenade = ratings........ trust me


----------



## JoergS

I see this got censored at the Trumark forum... they deleted my thread.


----------



## Tex-Shooter

Joergs, That was a fun video! -- Tex-Shooter


----------



## slingshot awesome

cool but ur out yo frickin mind dude


----------



## NaturalFork

NICE!!!! going viral.


----------



## Rayshot

Is in a news article/link on Msnbc.msn.com

News link, to circular blade shooting


----------



## M.J

Rayshot said:


> Is in a news article/link on Msnbc.msn.com
> 
> News link, to circular blade shooting


That's great!
It's funny that I never think of Joerg's stuff as "deadly" like the article says.
Anyone who knows him from the forum knows he's just having a good time.
That doesn't make for a zesty headline, though. 
Good work, Joerg!


----------



## e~shot

Wow, just saw the video...


----------



## Nico

JoergS said:


> I see this got censored at the Trumark forum... they deleted my thread.


They deleted your thread?

Why?

If anything you just gave great press to the use of tubular rubber and how well it handles heavy projectiles..

I really like this video and I feel that this idea of yours can be expanded upon as I have always wondered of ways to fire circular blades and your project and video are a step in that direction which can still be evolved further. I have heard of similar things before in conversations with some people but you are the first to bring life to these ideas.

Nico


----------



## Slingshots rule

cool


----------

