265 replies to this topic

[CaptainSlug]

Secondly I would like to ask did you start constructing it yet or are you just in the design stage?

I started the first design but didn't get all that far before finding many mechanical problems. I have not started this version yet because I need to make sure the CAD version will be as easy to machine as possible with the equipment I have access to. Tolerances on this many moving parts are very tight and having a detailed plan before you start working will save a ton of time.

[Jergling]

Oddly (for me), that first idea made perfect sense to me. I was thinking about making an airsoft like that, especially the rotating loading, I thought it would be effective to crank the plungers back by screw-like threads in the outter casing. Is that what i'm seeing?

[CaptainSlug]

The mechanical energy required to prime a plunger strong enough to fire a dart is just too high for a battery powered motor to overcome. Hence why I eventually went with a mixed system.

Edited by CaptainSlug, 28 February 2007 - 07:22 PM.

[urbanfighter7]

Look at airsoft gun motors and airsoft gear boxes.

Edited by urbanfighter7, 04 March 2007 - 01:09 PM.

[Uncle Hammer]

Thats propelling 6mm bb .2 gram bb's, not fullsize nerf darts.

[Jergling]

Looking at the first design, I noticed that the hopper either moved or was removed, were the darts going to be picked up by a notched gear thing at the bottom of it, like a rotational breech? Is there any way we could view that model in 3D for ourselves? I understand things better visually, and the only 3D/CAD program that I have is Sketchup.

[CaptainSlug]

I'm not going to share any CAD files at present because I don't want anyone pre-empting me. Not only because I want this to be MY project, but also because I haven't done preliminary practical tests on individual parts vital to it's operation. Results of those tests will dictate potential changes to the design.

Now, the feeding teeth rotate with the barrels in order to push the darts along a ramp that rolls the darts until they are lined up with the barrels so they can be ram-rodded into place.

The old design used a sliding breech, but that required far more space and was much more complicated to actuate. The new design only has one part being actuated by the rotation of the barrels.

[Jergling]

Oh, I see. Is this whole thing based on rotating, I know you said it was initially to be drill driven, then hybrid. Just wondering. All the distinctly moving pieces I see seem to be threaded, spiraled or otherwise screw-like.

Regardless, the way you've worked this whole thing out is still amazing to me, my mechanical building skill is minimal.








Edit: had a few missing commas, periods, capitals (very careful about that now)

Edited by Jergling, 10 March 2007 - 09:32 AM.

[CaptainSlug]

It's a hybrid system because the rotation will be driven by a DC Gear Motor. The surplus motor I purchased is a motor from a Saturn, and is either a windsheild wiper or power window motor, I'm not sure which.
The rotation of the barrels and all of the mechanism attached to it work to cycle the darts. The ram rods get actuated forward to push the darts into the barrels by interacting with the cam track. The piece you see here in red.

They get retracted by an extension spring.
Once the ram rods reach the forward most position the trigger valve that's built into them releases the 10psi air supply and the dart fires.

The rotation also allows the feeding teeth to roll the darts into place against the ramp explained in the previous post.
Those are the only two things the drive motor actuates.

The electrical system triggers the solenoid valve that controls the air supply so that it's only vented when the trigger is pressed.
It also supplies power to the blower fan that feeds the darts through the tube feed.

The firing of the darts is a pneumatic action. An HPA tanks provides far more energy than a battery every could when it comes to firing a dart. It is down regulated a huge amount to conserve the tank, and to make the rest of the gun easier to engineer. The pressure level once it leaves the tank is only 10 to 15psi. The internal tank pressure can be upwards of 3000psi.


In other news I just sold a Nerf gun for more than enough money to help me purchase the initial supplies for this project. I just ordered the HPA tank and it's matching regulator.

Edited by CaptainSlug, 10 March 2007 - 05:08 PM.

[Flaming Hilt]

This is nothing but a note of encouragement. Your works never cease to amaze me, CS. This has come quite a way since your first post. Keep at it. : o)

[CaptainSlug]

Well bizarrely I had another stroke of inspiration as to how to feed the ammunition. I was worried that the fan on the hopper would have to be a centrifugal blower in order to output enough pressure to feed the darts through the tube. And that type of fan could have a rather high current draw and would produce quite a bit of noise.

I went ahead and researched actual vacuum conveyor systems and found out how they work.


The systems that don't have to lift heavy load use a ridiculously simple air jet coupling linked in the tubing to create suction through output flow. Making one of these would be very easy.

What it would accomplish is

1. Reduce weight
2. Reduce noise output
3. Reduce battery consumption (since it's an air powered part)
4. Remove the need to make the dart hopper air tight since it conveys by suction
5. Simplify the trigger operation (the trigger will only need to turn on the drive motor and the solenoid valve that lets gas operate the vacuum conveyor and dart firing)

I'm also interested in running experiments to see if this part alone would have enough power to fire darts in succession. I will try to make a prototype of this part some time soon since it doesn't involve any expensive materials.

Edited by CaptainSlug, 17 May 2007 - 11:01 PM.

[Z-man12]

Well I for one will be intrested to see how this works. I am curious to see how this teconology could be used, if it has enough power its slef to shoot darts, to make homeades.

Good luck CS.

[bored kid93]

The useability of this gun would be incredible, I could see the gun being used for weeding the enemy out their bunkers with the spray of foam around them , they would have no choice but to surrender. It could also be pretty effective as a psychological weapon. I know I'd be scared as hell if I encountered that thing on the field.

[wallymaniac]

All I know is no matter how well it works, I'd be scared shitless just seeing that thing in a war. If anyone could pull this off, it'd be CS.
Or maybe Boltsniper.
But probably CS.

[SirBlastalot]

If you could figure out a way to produce several of them, I would pay a LOT of money for one of these.

[CaptainSlug]

Depends on your definition of "a LOT of money". I can't work on this at present because I lack time and money to get it started/finished because I'm trying to graduate by August. I probably won't have either until September.

[SirBlastalot]

I understand that this is a huge project. I can wait, and even if you only ever make one, I'd love to just see a video of it. As to how much I'd pay, that would depend on the performance, assembly time, and how much your materials cost.

[Legion]

Making several of those would be very costly and time consuming. It might be easier, once he finalizes a model that meets or exceeds expectation, to make the schematics and sell those. Multiple CSHGs would probably cost a fortune just to ship.

[CaptainSlug]

I'm going to finish a working A.B.P.5K before even touching this project. I won't be able to make any progress on this gun until September.
Now that I have a working paintball tank setup I can perform more practical component experiments and determine how best to proceed to make the gun usable in a Nerf War. The first obstacle to tackle is developing a working and efficient ammunition carriage and feeding system since that's the most complicated part to get working properly.

I'm not even going to think about making more than one yet. So the answer for now is: No

Edited by CaptainSlug, 28 May 2007 - 03:21 PM.

[Ronster]

If you could, it would be really sweet if you made it look like the new machinegun turret in Halo 3.


Bigger


Bigger

[CaptainSlug]

No, just no. That's terribly unergonomic and this Gatling gun isn't even going to be much longer than a longshot. None of my projects are going to be about theatrics or styling. The shape is determined by the function.

Edited by CaptainSlug, 29 May 2007 - 07:07 PM.

[Ronster]

Just a suggestion. Sorry.

[CaptainSlug]

I'm currently having a change of heart on this project and I would like to explain what has been going through my head since attending the past two Nerf wars. Particularly after talking with some of the veterans about how Nerf modification has been reaching levels of complexity that only a small handful of people are able to reproduce.

1. Weight as a handicap.

Nerf wars are fun because you can run around and dodge the incoming projectiles. Using heavier or bulkier weapons makes it that much harder to maneuver effectively in a war. Even using a comparatively light system weighing only 5 or 10 pounds has had a noticeable effect on my ability to maneuver in a round.

2. Psychological effect of overpowered weapons.

If you are perceived as a serious threat by the other players they will tend to avoid you or give you an abnormally large space cushion. In large open playing fields this can lead to slow standoffs. Add to this being weighed down to the point that it's difficult to chase people, you end up with fairly boring rounds.

3. Keep it simple.

A complicated weapon does not lend itself to reliability in a Nerf war.

4. Larger targets are easier to hit.

This really doesn't need an explanation.


There's no guarantee that this post is a death knoll for this project. But I do need to reevaluate the direction that this project is heading in. But to me I will never see the point in spending alot of time making something that I cannot actually use for the purpose it was intended for. The current mechanism will work, but I need to think about alternative means for ammo storage.

Edited by CaptainSlug, 08 August 2007 - 11:52 AM.

[Rover]

I think you have touched on some important points CS. May I suggest re-evaluating the concept and taking it in a more "emplaced gunner" kind of direction? I could see this being a viable option for a weapon of this type. Just throwing out an idea mainly because I don't want to see this project die.

[Ronster]

Just camp the flag and your team'll awlways win!