25 replies to this topic

[PVC Arsenal 17]

Semi-auto dry-fire video (I have no darts): http://s237.photobuc...ent=airtest.mp4
Electro Pneumatic Revolver (EPR) proof of concept.

More pics and vids tomorrow... I'm exhausted.

Edited by PVC Arsenal 17, 21 February 2011 - 12:47 AM.

[WicketTheModder619]

Good job and nice build!
It looks pretty, it's semi-auto, and it works! The only other thing is ranges. How far can this thing fling darts? Oh, and it is a little hard to tell, so could you clarify how many barrels there are?

[PVC Arsenal 17]

Good job and nice build!
It looks pretty, it's semi-auto, and it works! The only other thing is ranges. How far can this thing fling darts? Oh, and it is a little hard to tell, so could you clarify how many barrels there are?

Thanks for the comment. There are 15 barrels per rotary clip, and they are removable if you need to reload quickly. I'll figure out ranges within the next few days, but as with anything pneumatic, it's up to the regulator settings to produce the results I want.

Edit: It's selectfire. There is also a full-auto mode that I did not demonstrate. I can also program a burst mode but I don't see the need.

Edited by PVC Arsenal 17, 21 February 2011 - 01:06 AM.

[WicketTheModder619]

That makes it even Awesomer! Removable clips, full auto, and burst fire. Will you be making a write-up? I have always wanted a burst fire blaster.

[the mod man]

On full auto, how fast do you think it shoots?

[MrPzowned]

What kind of regulator is in there? I would've used something by Norgren or Monnier, they make nice stuff.

[Kyrativ]

That is hands down one of the most awesome homemades I've ever seen.

I look forward to ranges and any more details on the build process. The whole build looks quite well put together and is very organized looking.

[Kid Flash]

Are you using co2 in that co2 tank? Is this just a dumbed down paintball gun? I'm just trying to understand.

[PVC Arsenal 17]

The regulator is a Palmer Stabilizer and yes it runs on CO2. This gun was designed from the ground up to be a reliable platform for shooting odd-shaped 1/2" diameter projectiles - nerf darts among other things. The heart (or should I say brain) of the gun is a microcontroller programmed to synchronize the indexing and firing sequences.

It is not a paintball gun, though I suppose it has much in common with one.

[Eh Watt]

Oh, man. You've done it again, Peavy-C. This thing is fantastic. All of the guns you ever build seem to fit my definition of dream cannon perfectly!! The turret, the stuff on top all combine to make this look great. The coolest part is that you used that microcontroller to synchronize the entire rotation mechanism!! Ha! Just... just awesome. Fabulous, fabulous job.

[PVC Arsenal 17]

Thanks for the comments.

Once again I've discovered the huge advantage of tweaking projects like this in code. In the previous video I was using the gun with the solenoid's firing duration set a bit too high. I changed a few numbers and realized that I can now get a huge RoF boost. Here is full-auto uncapped: http://s237.photobuc...current=fau.mp4

[Kyrativ]

I'm wondering if it would be possible to combine the burst fire functions of this with the homemade magstrike piston doo-dad that was around here a while back...seriously this could revolutionize nerf homemades. Could you imagine a magazine fed burst fire capable nerf homemade?

[Boot]

Wow, this is very impressive! It is interesting to see that an electronic valve mechanism seems to be much more effective and flexible at creating a semi or full auto setup. From what I gather, this has no "airtank", at least in the way a normal air pressure blaster does, does it work by simply opening and closing an output from the high pressure air tank very quickly?

As usual, impressive work. I am amazed at how well the turret rotation is synchronized with the valve activation (do they operate from the same servo, is the turret turned pneumatically, or are the two systems separate?)

Also @Kyrativ

From what I gather, this accomplishes full/semi auto fire through electronic activation of solenoid valves. It is the digital solution to creating a automatic blaster.

The cleverly made homemade MS valve works as an analogue solution to the same problem. Pressure is constantly introduced into the system, and it acts as a kind of pneumatic capacitor, releasing bursts of air.

Combining the two would give exactly the same effect, just with the disadvantages of both (except the oscilating motion could be used to work a breech and clip, although the same thing could be done in this case, using the turret servo to open and close a breech). You would need some source of electric power, and you would not have the flexibility of the "Archangel".

If you want burst fire, this can achieve that with some different programming, or, in the case of the homemade MS valve you could set up some sort of time activated valve (which would be super cool )

[PVC Arsenal 17]

To clear up any confusion, the solenoid valve merely pilots a quick exhaust valve which releases air from the small reservoir above the barrels. I could have used it to shut on and a off a stream of air but then the gun wouldn't have nearly the same performance. The barrel assembly is turned by a DC motor with a planetary gearbox. The reason for using two electronic systems in this way is to have complete control over the entire operation.

Thanks again for your replies.

[Kyrativ]

ahh I see, i was kinda really excited about this when i first saw it and my ideas were running a little rampant haha.

Anyway still great design!

[GeshmanWG]

That makes it even Awesomer! Removable clips, full auto, and burst fire. Will you be making a write-up? I have always wanted a burst fire blaster.

I too would like to know if you plan on making a write-up for this baby. It looks very impressive and seems like it would be a fun weapon to use. Especially considering you can tweak it to your liking.

[TantumBull]

That makes it even Awesomer! Removable clips, full auto, and burst fire. Will you be making a write-up? I have always wanted a burst fire blaster.

I too would like to know if you plan on making a write-up for this baby. It looks very impressive and seems like it would be a fun weapon to use. Especially considering you can tweak it to your liking.

Its not a full write-up by NH's standards, but his thread here offers some more in-depth information.

[shmmee]

That's really impressive. What's your professional/educational background? This deffinately isn't something the un-trained idiot could create.

[Doom]

PVC Arsenal 17 is still in high school as far as I know! He's definitely one of the best, and he can only get better with more knowledge.

[PVC Arsenal 17]

Thanks again for the comments.

EDIT: better video: http://s237.photobuc...nt=HPIM0976.mp4

Here are some videos, excuse the crappy quality:

http://s237.photobuc...current=fa1.mp4

http://s237.photobuc...=0225012021.mp4

As you can see there was not one misfire in either mode. The indexing is dead-on accurate. However, if the barrel assembly is put back on out of line with the air outlet, there is a "synchronizing period" of a couple shots before it gets back in tune. Once it is, though, it's consistent. I'm still working on ways to eliminate that problem but overall I can't complain about how well the whole system is working.

And of course a size comparison to my other toys:



Note the electronic guts sticking out... there is much refining left.


BTW I'm a first year mechanical engineering student. My building ability is mostly due to years of tinkering, though. I want to share what I've learned throughout this project so others can build things like this too, so yes I will do a writeup when I get time.

Edited by PVC Arsenal 17, 25 February 2011 - 11:00 PM.

[Aj]

Absolutely awesome project, have you ever considered making a 'heavy' version (ie higher firepower but lower mobility) - That turret coule be made into a great feeding mech for a belt rather easily.

Aj

[angelfalcon]

Great work.

I don't see the need for a 3 shot burst option - within the intended range, you'll almost always hit what you're aiming at. Using 3 times as many darts doesn't help. At longer ranges, I can see it helping a but more, but you're still going to loose the same amounts of darts on average to tag the target. You may as well use manual burst fire, seeing as there's no recoil.

One of my suggestions is this: More ammo. The auto fire seems to run out fairly quickly on full auto. I think for you're next iteration, you should add about 6-8 more barrels to the turret system - unless that raises issues with the indexing system, which I admit I don't completely understand.

The other is: Longer barrels. If that thing is as powerful as it seems, and has the potential the become more powerful - potential which it seems to have - then longer barrels are a necessity.

Lastly, I'm planning on going into a mechanical engineering program once I'm out of high school. Where are you studying, and how's it been so far?

Edited by angelfalcon, 01 March 2011 - 05:18 PM.

[utahnerf]

Is that handle Plasti-dipped? Also, sweet Ion, I have one too.

[Inferno Falcon]

Awesome, can't wait for a writeup.

Reminds me a bit of this: http://nerfhaven.com...ndpost&p=276864

[Doom]

The layout is fairly similar, especially with regard to the valve and gas reservoir (which really are in the only positions you can put them in). I didn't like what I did in FANG 3, so I scraped the thing shortly after taking that photo. PVC seems to have avoided a number of issues I had by building the entire thing off a tube and using electronics. I considered a similar layout for FANG 4, but I'm going for something completely different at the moment. Watch FANG 5 be a copy of this.

PVC, if you ever have any questions about math, engineering, or physics, I'd be happy to help. I might not have the free time to help often as I'm practically in grad. school right now and I'll be officially starting grad. school next semester, but I'd still be happy to help you. (And yes, I am studying fluid dynamics. Interior ballistics is basically a subset of that field, so I'd be even more knowledgeable about Nerf ballistics during and after grad. school.)

Edited by Doom, 01 March 2011 - 10:15 PM.