6 replies to this topic

[Doom]

I had intended to post this when the gun was 100% complete including an involved simulation and optimization procedure, but the project will have to go on the back-burner while my finger heals from a somewhat deep cut so I decided to post my progress so far.

A fair number of people here saw my original FANG Nerf gun. I didn't have too many expectations for the project, but I was satisfied with the result even though it wasn't perfectly reliable in its last state. FANG 2 is a different method of achieving semi-automatic operation. This time I am using a rotating barrel assembly much like the Eclipse but simpler as mine only involves rotating barrels and not a belt or revolver magazine.

I'd like to get this gun right, so I'm using an evolutionary development process. Multiple prototypes will be made or at least revised and each new/revised prototype will improve on the previous. Prototype 1 is nearly complete and will be shown below. Prototype 1 uses a manually advanced turret for simplicity.

I could go on and explain in detail precisely what I did and my justifications, but I type too slow at the moment and have already said most of what has been done on my personal website. I'd suggest reading the following links:

http://trettel.org/fang2.html
http://trettel.org/blog/cat/fang2



The gun is obviously incomplete in the photo above. The structural piece holding the trigger valve and trigger is temporary and only serves to help figure out the correct geometry. A second structural piece to attach the turret seal piece to the tees above it is not made yet. There's no handle shown because it hasn't been made yet. And the most obvious omission is every barrel--as I mention in the links, the barrel lengths are to be determined with computer simulation.



The gun part is shown closer above.



This photo shows the intended ergonomics, which actually are pretty good as is considering the trigger angle is wrong and there's no handle.

Edited by Doom, 30 March 2009 - 09:19 PM.

[b00m13]

I only feel sorry about the Fang series because they'll never be allowed in Nerf wars (too hazardous~!!)
Remember,... these are still supposed to be toys~!!
But other then that, I still want to say I love how your work's always so clean
*thumbs WAAAY UP~!!*

Edited by b00m13, 20 March 2009 - 12:04 PM.

[Daniel Beaver]

I only feel sorry about the Fang series because they'll never be allowed in Nerf wars (too hazardous~!!)

We would use them in Minnesota. We like homemades

Doom, this is very cool. I hadn't seen your website before, but I may be spending some more time there. I see that you link to spudfiles a lot; are you an active member over there?

[Doom]

Thanks for the replies.

I only feel sorry about the Fang series because they'll never be allowed in Nerf wars (too hazardous~!!)
Remember,... these are still supposed to be toys~!!
But other then that, I still want to say I love how your work's always so clean
*thumbs WAAAY UP~!!*

If you mean the power is hazardous, realize that my guns aren't any more powerful than most guns allowed at wars. I already had a silly rant about how pneumatic and dangerous are not synonyms. You can have any power level with any style of gun.

I intend to have a total gas chamber volume of less than 1 cubic inch if my earlier simulation is at least reasonably accurate. For comparison, the Titan has about 7 cubic inches of volume. Mine is very significantly less.

The muzzle velocity will be less than other guns allowed at wars (ex. the +Bow and some higher end SNAPs). This is intentional so I don't get safety complaints and I can get more shots per tank.

If you don't mean the darts will be hazardous, I hope you don't mean the gun itself will be. The aluminum gas reservoir, which is perhaps the weakest component, will have a safety factor of 4 over the burst pressure, which is higher than DOT certifications. Any components under pressure are made from metal with equal or greater safety factors than the gas reservoir's. My regulator acts as a safety to prevent pressurization of the primary gas chamber when it is not desired. A check valve prevents the QEV from firing when pressure is lost on the gas reservoir side. I also have a pop-safety valve to prevent overpressurization of the gas reservoir (which would open before the tank reaches the DOT certified operating pressure). This gun is a huge improvement over everything else in this aspect of safety.

I've done all I can to make this gun safe. Whether or not the public will perceive it as safe is another story.

</safetyrant>

Thanks for the complement about clean work. I try, but it doesn't always happen. This one looks pretty nice though, mainly because of all of the metal. There are some rough edges and sloppy constructions but they're not very visible in the images.

For the record I make no attempt to make my guns look like anything in particular. Function determines the form of my guns. I can appreciate the minimalist look I go for though.

We would use them in Minnesota. We like homemades

Doom, this is very cool. I hadn't seen your website before, but I may be spending some more time there. I see that you link to spudfiles a lot; are you an active member over there?

Yes, I am a member of Spudfiles. My username is btrettel. Recently I've been much more active there than here, though, I'm barely active here at all. 2009 should change that.

Edited by Doom, 20 March 2009 - 08:26 PM.

[rork]

Glad to see this baby coming to fruition. It may not look like it, but this is a massive improvement over FANG 1. I'm eager to see how it turns out.

[Doom]

My thumb is nearly healed and I should be able to put the finishing touches on this prototype starting Thursday at the earliest. I've already detailed what will be done from this point on in my blog.

There are plans brewing for a war at the University of Maryland this weekend, so I intend to debut the gun there if a war is actually organized. The gun will be singled as shown in the last photo and operate at a relatively low pressure and volume so I can gauge how many shots are necessary for a certain time duration (and to silence critics of my gun's supposed safety issues).

I plan to start futzing with semi-automatic mechanisms and larger turrets relatively soon. A small air cylinder with some sort of rotation mechanism is all that is necessary. I have a small list of improvements to include to existing pieces and those will be included in the final design. The biggest improvements would be adding stops to prevent side-to-side rotation and increasing the use of polycarbonate instead of expensive FDM so I can use a higher capacity turret.

I'd appreciate any thoughts, questions, or suggestions.

[um7kay]

My thumb is nearly healed and I should be able to put the finishing touches on this prototype starting Thursday at the earliest. I've already detailed what will be done from this point on in my blog.

There are plans brewing for a war at the University of Maryland this weekend, so I intend to debut the gun there if a war is actually organized. The gun will be singled as shown in the last photo and operate at a relatively low pressure and volume so I can gauge how many shots are necessary for a certain time duration (and to silence critics of my gun's supposed safety issues).

I plan to start futzing with semi-automatic mechanisms and larger turrets relatively soon. A small air cylinder with some sort of rotation mechanism is all that is necessary. I have a small list of improvements to include to existing pieces and those will be included in the final design. The biggest improvements would be adding stops to prevent side-to-side rotation and increasing the use of polycarbonate instead of expensive FDM so I can use a higher capacity turret.

I'd appreciate any thoughts, questions, or suggestions.

His name (Doom)explains his gun.