37 replies to this topic

[Ranger Dave]

I am Ranger Dave, I'm a Mechanical Engineer at The Ohio State University, and i build unconventional nerf weapons. Recently I came across a pair of broken Tommy-20 flywheels in my friend Xellah's parts bin, I decided that there was just too much potential to leave them just sitting there and set to work. After one trip to radio shack and 7 hours of tinkering around i was left with a beautiful launcher that could sail darts farther than 50 feet. For anyone with a pair of flywheels just lying around gathering dust I highly recommend tinkering with them,they are the perfect size for integration because they can fit just about anywhere, plus they're just so fun.
This is my weapon so far, i plan to build and integrate a clip as soon as possible.

Materials Needed
1X Pair of flywheels
2X Radioshack Metal Gear 1.5-3 VDC Motor
1X Push-button or flip switch (don't use a momentary switch unless you plan on holding it down for as long as you use it, its a pain in the ass)
1X Three AAA Battery holder
Whatever you plan on mounting it to or integrating it into
Wires
Soldering Iron
Drill
Knife
Hot Glue

Step 1

The first thing your going to want to do is replace the motors in the flywheel sub-assembly, in short they suck and they are one of the main reasons the tommy twenty isn't taken seriously. You can replace the motors with any motors you like as long as you can get them centered properly. I choose two 3 volt motors with 8700 RPM (no load) because they were the exact same size and shape of the motors i was replacing, i went with these because it was easier, but if you get motors with higher RPM you could probably get even better distance than me.

Step 2

Now that its all apart, get rid of the shitty old motors, make them into a desk fan turn them into a RC car i don't care just keep them out of the gun. Next measure the gear on the top of your motor and find a drill bit about the same size or a little smaller.

Step 3

Once the wheels fit re-assemble the holder and make sure the motor leads are pointing at eachother. Then use hot glue to attach the wheels to the gears take care to get them as even as possible, too much wobble on the axle and your gun will be worthless.


Step 4

This is very simple the motors say which lead is positive so use one color of wire, i used green, to solder all of the positive motor leads to one side of the switch. Then solder the positive wire from your battery holder, this is the red wire, to the opposite side of the switch. Next solder the negative leads from the motors and the battery holder together, it couldn't be simpler. Now i used a 3 AAA battery holder which puts 4.5 volts through the two three volt motors, which makes them run a little faster than with just 3 volts but feel free to do whatever you want power wise, just don't do something stupid like pour 18 volts through these poor things you'll just end up frying them.

Step 5

Now just for proof of concept i used some rubber bracelets i had lying around to secure the contraption to my arm and confirm that it works, since it did i decided to put it into something a little more stable. This is where my instructions end because i'm pretty sure you can figure out how to attach your flywheels to whatever it is that you want to attach them to, i recommend mounting them on your arm just for the coolness factor and because if you do Humans vs. Zombies like me it could end up saving your life when your primary runs out of ammo, or you need something light and easy to run with but still has a lot of fire power. its like having a something better than a barricade strapped to your arm.

Step 6 (if your still reading)

It is a thing of beauty, the contours of the wrist guard that i used perfectly fit the shapes of the flywheels and battery pack, plus the palm is big and sturdy enough for me to cut a hole in and add a button. Just make sure that everything works before you glue it into place, it is no fun to have to take it all apart and figure out which wire snapped.

This is my setup so far, it is far from complete but it is still very effective. My next project is to create an automatic feeding system with an integrated easily re-loadable clip.

Range Test
I use whistler and tagger darts because they fly the best because of their big heads for the wheels to grab.
I shot them down my hall way which is covered in 1sf tiles.
A ten shot range test resulted in an average range of 54 feet with a standard deviation of 1.2 feet.
For a flywheel gun this is very good.

If anyone has any suggestions or questions feel free to let me know. I hope this has been informative and possibly changed some peoples opinions of flywheels. I can post a video of it working if you guys want. Also i can't come up with a good name for it.

Also my next write up will be how to turn the vulcan into a legitimate weapon not some piece of crap that is more effective to just throw at someone.

[KoRnEd]

That looks awesome. Just for clarification, do you hand feed the darts into the flywheel?

[Ranger Dave]

As of now i have to hand feed each dart into it which is a pain, but i plan on changing that and building some sort of clip as i need my other hand to hold my Uber-Vulcan

Edited by Ranger Dave, 24 January 2012 - 01:51 AM.

[shmmee]

I like how it's basic enough to simply slap onto the side of nearly any sized blaster. Especially if the blaster already has an internal battery pack (NF, firefly...) Though those only have a pair of AA's, instead of a trio of AAA's.

[Xellah]

Wow, nice write-up. You turned a conversation between Mike and I at Cane's into... this.

As we spoke about before, a hopper of some sort would do the trick. You would have to control how fast you feed the darts (maybe through a spring-loaded RSCB-ish set-up). Plus you need to keep your magazine small enough so that it isn't interfering with your Vulcan firing hand.

[DudeRadster]

Pretty awesome. Think you could make a direct plunger that straps to your forearm?

[Pointman9]

Maybe you could mount a length of .5 in PVC pipe in line with the flywheels and blow the darts into the flywheels? You could always mount a ball valve on the end closest to you to keep them from falling out the wrong end, while still allowing easy reloading.

[Ranger Dave]

Pretty awesome. Think you could make a direct plunger that straps to your forearm?

Actually i don't think it would be that hard to make a direct plunger attachment, if you think about it all you really have to to is cut apart a nightfinder and create a trigger that is activated by your hand.
When i was looking up ideas for arm mounted guns i found spandxbunny had built a double nitefinder manta style gun which is a similar idea of adding a direct plunger to mine.

Maybe you could mount a length of .5 in PVC pipe in line with the flywheels and blow the darts into the flywheels? You could always mount a ball valve on the end closest to you to keep them from falling out the wrong end, while still allowing easy reloading.

That might work but i'm not entirely sure i understand what i would use to blow the darts into the flywheels. I think that my best bet is to have a mechanical arm the pushes the darts into the wheels, but i need to create some sort of clip first. One thing i was thinking of was just getting one of those quick load dart tag blasters and just "borrowing" the entire clip assembly from it.

*This 2 post a day allowance is kinda annoying, I'm just saying"

Edited by Ranger Dave, 25 January 2012 - 11:38 AM.

[Langley]

You could try using a linear clip. If you mounted a dart-filled tube (1/2" pvc?) behind the flywheels, you could attach a small spool to the axel of one of the flywheels that reels in a cord. Connect the other end of the cord to a rod or plunger that pushes the darts down the tube into the flywheels. You can change the feed rate by using different diameters of spool, and you can reset the whole thing by using a DPDT center-off switch and wiring it up so that one position reverses the motors.

You could also do something similar with a Rack-and-pinion instead of the cord and the spool. Maybe if you have some lego or knex parts lying around you can Frankenstein them into a feed mechanism.

[Pointman9]

Your lungs would work. But bringing essentially a short blowgun up to your face quickly and not hitting yourself with it could be challenging...

[cheyner]

The tube magazine could work, use a end cap with a hole drilled into it so you can attach some vinyl tubing. Then simply run it up your arm and to a clip on the neck of your shirt, simply blow to load another dart.

Edited by cheyner, 25 January 2012 - 04:15 PM.

[BOSS9]

The problem with all these ideas is that if you angled your arm down at all while the flywheels are on, you'd lose all your darts in a second. A tubular magazine with loose-ish fit (a dart won't fall out on its own) and a slot running the whole length of the tube. Make a follower to ride inside the tube with a small handle coming out of the slot. To fire, push the handle forward.

[Ranger Dave]

First off sorry about the long response, I'm just trying to make the most out of my two allowed posts a day. I must admit I didn't expect my first Mod to go over so well.

You could try using a linear clip. If you mounted a dart-filled tube (1/2" pvc?) behind the flywheels, you could attach a small spool to the axel of one of the flywheels that reels in a cord. Connect the other end of the cord to a rod or plunger that pushes the darts down the tube into the flywheels. You can change the feed rate by using different diameters of spool, and you can reset the whole thing by using a DPDT center-off switch and wiring it up so that one position reverses the motors.

You could also do something similar with a Rack-and-pinion instead of the cord and the spool. Maybe if you have some lego or knex parts lying around you can Frankenstein them into a feed mechanism.

A linear clip would be the most compact way to hold darts, however like BOSS9 said the darts would fall through every time I lowered my arm. i could potentially build a catch to prevent that from happening but i'm leaning towards the piston idea just because it would me much easier for me to build and plus it would make the gauntlet fully auto. I already have most of the parts and i'm pretty sure I could grab the rest from the machine shop on campus. Please excuse my crude drawing skills, i was just using MS paint and a track-pad.

I was thinking something like this for the feeding system, and i have a pretty good idea for the clip, although i'm going to use Auto CAD to draw it up first.

Your lungs would work. But bringing essentially a short blowgun up to your face quickly and not hitting yourself with it could be challenging...

You have much more faith in my reflexes than do. Technically, that would work the only thing is I am really good at hitting myself in the face. I don't trust myself with that level of coordination.

The tube magazine could work, use a end cap with a hole drilled into it so you can attach some vinyl tubing. Then simply run it up your arm and to a clip on the neck of your shirt, simply blow to load another dart.

That would work better and its not a bad idea, i might use it in another blaster i'm working on just because of how simple it is. I'm al for not having to do as much work.

The problem with all these ideas is that if you angled your arm down at all while the flywheels are on, you'd lose all your darts in a second. A tubular magazine with loose-ish fit (a dart won't fall out on its own) and a slot running the whole length of the tube. Make a follower to ride inside the tube with a small handle coming out of the slot. To fire, push the handle forward.

I'm planning on doing this actually, i'm in the midst of gathering parts to make a guitar gun and that's the perfect way to feed the darts up the neck.

[mysterio]

I would suggest using Boss9's dart fit idea with the vinyl tubing leading up to your mouth, Camelback style. It's too bad the clip length is limited by how large your forearms are though.

[KainZero0133]

my first thought: double barrel storm bolter (warhammer 40k: grey knights) like these:

http://www.40kforums...0faec13e457.jpg
http://3.bp.blogspot.../pagk1-gull.jpg

aside from my love of warhammer....This is a great idea overall, and perhaps finding a way to rig up a clip-fed nerf gun with double barrels and a shell would be practical and fun. as far as a trigger it could still be the button for ease of access, and maybe use most of a gun already out for the shell to hold it all together. either way its cool to see.

[Curly]

I think it would be easier and less of a pain to simply make a dart pusher for one dart. It's possible for this to be low-profile enough to allow for a normal primary, which is far more effective than a wrist-mounted blaster. I would prefer one quick backup shot than a vinyl cyborg arm. That's just me though.

[Ranger Dave]

I think it would be easier and less of a pain to simply make a dart pusher for one dart. It's possible for this to be low-profile enough to allow for a normal primary, which is far more effective than a wrist-mounted blaster. I would prefer one quick backup shot than a vinyl cyborg arm. That's just me though.

If you want to go unnoticed a simple one shot blaster would work because it doesn't draw attention, but if you want to intimidate people then the bigger the better. All of my blasters are used for Humans Vs. Zombies, so if the zombies see a seemingly unarmed human they attack, But if they see someone armed to the teeth they hesitate giving you the advantage.

So I got to thinking last night and came up with this design, it isn't quite finished yet mostly because i haven't designed the feeding mechanism i still have to do the calculations for the piston.

Depending on how I spring load the orange piece it should hold at the very least 25 tagger darts. At this point it is going to just become my secondary due to the decent range and now large clip.

Any Questions?

*Edit* In case you can't figure it out (I know at least one person won't be able to wrap their head around this) the case has been taken off and placed in front so you can see the internals.
Also it might not be obvious because an engineering drawing like this does not include measurements, but it fits around my arm. The outer diameter is 7.5 inches.

Edited by Ranger Dave, 26 January 2012 - 03:23 PM.

[mysterio]

Ranger, perhaps use the full-auto pusher in the Tommy 20?

[Ranger Dave]

Ranger, perhaps use the full-auto pusher in the Tommy 20?

If i can find the rest of the Tommy 20 that the Flywheels came from i would totally use it, but if not i'll have to replicate it somehow.


So i spent about half an hour just messing around with my design and i made a few changes.

I have to now get a hold of these parts.

[Xellah]

I still have the rotation mech from aforementioned Tommy 20. It's gone through some light modification (threaded rod through the center axis for a semi-failed franken-blaster), but it should still work for your purposes. I'll fetch that for you tomorrow at the mod party.

You are going to have to fabricate a new dart-pusher though. The mech is also quite bulky. These two factors will most likely make this feeding mechanism more work than it's worth. We'll try it out and see.

Langley's suggestion is probably your best bet for ease of use and simplicity.

[Ranger Dave]

I still have the rotation mech from aforementioned Tommy 20. It's gone through some light modification (threaded rod through the center axis for a semi-failed franken-blaster), but it should still work for your purposes. I'll fetch that for you tomorrow at the mod party.

You are going to have to fabricate a new dart-pusher though. The mech is also quite bulky. These two factors will most likely make this feeding mechanism more work than it's worth. We'll try it out and see.

Langley's suggestion is probably your best bet for ease of use and simplicity.

That's great news, i'll take a look at it today when i'm over. The only reason i'm hesitant about using it would be that it would turn my idea into basically just gutting a Tommy 20 and strapping it to yourself. Which is technically what i'm already doing but doesn't sound as cool.

Also which of Langley's suggestions are you talking about?

You could try using a linear clip. If you mounted a dart-filled tube (1/2" pvc?) behind the flywheels, you could attach a small spool to the axel of one of the flywheels that reels in a cord. Connect the other end of the cord to a rod or plunger that pushes the darts down the tube into the flywheels. You can change the feed rate by using different diameters of spool, and you can reset the whole thing by using a DPDT center-off switch and wiring it up so that one position reverses the motors.

You could also do something similar with a Rack-and-pinion instead of the cord and the spool. Maybe if you have some lego or knex parts lying around you can Frankenstein them into a feed mechanism.

Because he's dead on with the Rack and pinion idea if i were using a linear clip. The only problem is the three foot piece of 1/2" PVC would only hold about 13 darts instead of my cylinder clip which will hold 33 minimum depending on how it is spring loaded. (I must admit i read piston the first 8 times i read your comment Langley and for that I am sorry) I couldn't connect a cord to the flywheels because they do not have enough torque to pull a string/darts and spin up. Plus that would make one motor faster than the other which leads to bad things. Also the motors that I used are unidirectional so I couldn't reverse them.

A Rack and Pinion would probably work too if i have the rack spring loaded to return and the gear was missing teeth on one part of it.

By the time I'm done with my Sonic Gauntlet (Sonic because it makes noise, shoots sonic darts, and because i wanted to throw a Dr.Who reference into one of my guns) it will probably look like the love child of Samus, Megaman, and a Raider Drum. Hopefully I can keep it under 5 pounds.

Edited by Ranger Dave, 27 January 2012 - 12:36 PM.

[Ambience 327]

I like the design you have going for your "round the arm" drum-feed, but I have a question. The way I understand it, the reason Streamline darts were invented is because the standard Nerf darts (i.e. a head with a larger diameter than the foam behind it) wouldn't feed properly in a magazine due to the odd shape. How do you propose to solve this problem since you are planning to use sonics/taggers?

[mysterio]

He could add spacers to the back of the dart separators to offset that.

[shmmee]

To expound on Langleys linear clip idea - use a "retract-a-badge" as your spring and cord to pull darts towards the flywheels and an actuating escapement arm to limit dart feed to one per cycle. That would be the simple solution...

Though the arm mounted drum clip looks pretty friggin' cool.

[Ranger Dave]

I like the design you have going for your "round the arm" drum-feed, but I have a question. The way I understand it, the reason Streamline darts were invented is because the standard Nerf darts (i.e. a head with a larger diameter than the foam behind it) wouldn't feed properly in a magazine due to the odd shape. How do you propose to solve this problem since you are planning to use sonics/taggers?

Thank you for pointing this out Ambience, I hadn't considered that. Honestly I have no clue how to prevent this from jamming because of the inconsistent diameter of the darts.
For a quick fix mysterio is right on track, all I really need is to have the same diameter to prevent jamming, but then i would also sacrifice range because the longer something is in contact with the flywheels the more they slow down. And if i just added a spacer to the back of the dart then it would hit the flywheels after the head of the dart has already gone through and slowed it down which means the fly wheels will hit it with lower RPM which will then slow down the dart.

I could try and switch to streamlines but that really just postpones the problem. The real problem is nobody has really come up with a good design for a Tagger dart clip. (the reason is pretty obvious, i mean all clip guns are designed for streamlines) The legitimate clip i can think of is in the quick 16, I want to see how they solved the problem for that before i decide to do a complete design change.

Personally i like tagger darts more than streamlines so i'll start to work on this challenge. Some friends of mine and I meet every friday and do Nerf stuff, i'll see if we can't come up with a solution. in a mean time any ideas are appreciated.

*edit*
shmmee, if it turns out i eventually have to scrap the drum idea i like the "retract a badge" solution.

*edit 2*
After lurking on the forums more I've come to the conclusion that its about time someone figured out how to make a sonic/tagger clip.

Edited by Ranger Dave, 27 January 2012 - 04:35 PM.