16 replies to this topic

[Carbon]

SPANO was pretty cool in a lot of ways, one of which was all the cool mods and projects that were being shown about. This project came about from several different conversations and observations:

1. Finding for myself that Mavs really suck for outdoors,
2. A secondary with several ready shots would be nice.
3. A mod that leaks doesn't matter if the gun puts out enough air.

Thinking about where the seal is bad on a Mav led to a turret design, which I thought would go well on a SNAP...because it doesn't matter if it leaks, as the SNAP puts out plenty of air. So, here's my proof of concept turret:



The barrel disk has half couplers on it, glued down. The back is just a stub of 1/2" PVC for attachment ot the gun.

The concept is prety simple. The leakiest part of any turret is the interface between the gun and the barrel disk. So, I coated that entire area with foam craft sheet, to minimize the leaks. I made the squared out of hardboard, something that is easily workable, but very stiff.

Here's the exploded view:


And, I tossed it on the SNAP-1 with a few dogbone barrels:


It's a beautiful day with no breeze, so I got to do outdoor range tests...and I was pretty surprised.
63'
66'
78'
78'
85'
85'

It definitely loses range, but not as badly as I had thought. Since my goal for this is a springer sidearm, I could use a smaller SNAP body and still get the kind of range I'm hoping for.

Now, the biggest thing: improvements to be made. And there's plenty.

1. I'll be swapping the hardboard for some manner of plastic, as it's just cleaner to cut.
2. Epoxy. This thing wouldn't last 5 minutes in a war, as it's all held with just hot glue.
3. Additional support. The center screw will lend itself for this perfectly.
4. Straight cuts on my couplers. My couplers weren't cut straight, so my barrels aren't straight. There's ways around that, for the second version.
5. More barrels. This design will work for as many barrels as you want, for air or spring, I'd imagine. A 3" square worked well for the math of centering everything. It also allows you a good way to center up the barrels for each turn without an indexing system.
6. An indexing system. A round turret would demand it.
7. And the holy grail, an auto-rotate system.

Edited by Carbon, 15 July 2007 - 04:31 PM.

[sam]

Awesome! Here are some ideas/suggestions:
1.Try to find a spring that will hold the two pieces of the turret together for a better seal, like the AT2k turret
2. If it's for a sidearm, just use stationary barrels it should save a lot of space, and hopefully you won't have to use your sidearm a lot so reload time shouldn't be an issue
3. The indexing system should be super key, it should allow you to make the turret smaller, and give you a better seal.
Nice work, and I can't wait to see what you end up throwing this on.

[NiteWalker]

Another suggestion: make it so that the top barrel on your gun is under that barrel that shoots. I would think it would be easier to aim and I find it would look better. Any reason you placed it like you did?

[Carbon]

The spring is a good idea. I'll try addng one in between the two washers on the back. I was wondring what would happen when I had to start bearing down on the nut to keep it tight. As far as fixed barrels...they would keep it simpler, but I'm trying to avoid ramrods altogether, especially with my foam fit. Maybe if I can get some of that thinwall PETG...

I put it that way mainly so I could better support it while I was test firing it...it's only held together with hot glue, and I'm amazed it didn't blow apart. But you're right, and I didn't even think about it...down will look and work better, and the support rod will integrate nicely into the trigger cover.

Edited by Carbon, 15 July 2007 - 05:10 PM.

[Prometheus]

Nice Write-up. The improvements alone will helps others with turreted guns improve the ranges and accuracy of their guns. And I would cut down the back plate, so that you can load the darts from the back of the barrels, instead of ramrodding them, and it can still be a fixed system. Look at kBarkers clip mod for the NF to see what I mean.

[Carbon]

Excellent suggestion, Prometheus....anything to get around ramrods, and even easier than flipping barrels. Plus it's the advantage of always having the dart at the very back of the barrel.

Thanks for the ideas, everyone, I like where it's going. The general idea is taking shape...I tossed it on the front of the Syringe Popgun.


The size is about exactly what I want. What's interesting is that, even with the reduced air output of the popgun, it's not horrible...20' or so. Also, the hot glue isn't nearly as weak as I feared. I htink the hardboard fibers are giving the glue a bit more to grab onto.

Time to take up the saw and see about improving the syringe popgun a little...

Edited by Carbon, 15 July 2007 - 08:28 PM.

[Uncle Hammer]

Is there any o-ring seal between the turret the barrel of the gun? AT2k's perform much better with a seal there. The craft sheet is nice but an O-ring wouldn't hurt either.

Edited by Uncle Hammer, 16 July 2007 - 01:14 AM.

[Carbon]

Nope, no o-ring. The craft sheet is acting like a gasket to keep the seal (more like an engine block than anything else). I have the smooth surface of the hardboard facing the foam in order to maximize the surface area contact, as well. This actually provides more sealing surface area than an o-ring, anyway.

Edited by Carbon, 16 July 2007 - 08:25 AM.

[Athune]

Couldn't you drill holes in the stationary piece of hardboard to allow for rear loading of the barrels? That would cut down significantly on reload time. Of course, if you think that the darts would simply fall out, you could make the holes offset so that they would only line up with the barrels half-way between barrels lining up with the gun... If this isn't clear, let me know and I'll post a diagram.

[Carbon]

Couldn't you drill holes in the stationary piece of hardboard to allow for rear loading of the barrels?

Yeah, that's what Prometheus was saying, although he was talking about cutting away part of the back. Either way, it'll speed up the reloads and allow for fixed barrels.

[nerfer34]

Rear loading turrets would revolutionize nerf. That would be awesome.

Is there any reason why the turrets have square bases? Easier to cut? I think circular would look much better and be less danderous, and wouldn't catch on to clothing, etc.

If you want to mass produce these of just make them easier to make. You should design a base where the couplers fit into something, instead of you just really relying on the glue.

Great job so far.

[Carbon]

Square bases are a temporary measure, mainly because the cuts and math are easy for making everything nice and centered. That, and a square has a natural indexing system: if the corners are lined up, it’s correct. I’d like to use circles, but that’ll require a separate index system. I have some ideas, but didn’t want to cook those up with the initial test. That, and with raw materials I can think of offhand, I’d be stuck with making circles with a coping saw. No thanks.

A better design would see the front plate made out of 3/8” plastic, round, with milled holes that the barrels could be fitted into….but I’m no Captain Slug. My biggest limitation is the tools and workspace I have available.

My main concern with this phase was seeing if the craft foam could maintain enough of a seal. It’s been pretty successful. The next phase will be implementing the suggestions from here, seeing if the seal stands up with the back plate cut away, and making it more sturdy. I’m pretty sure that I can find off-the-shelf parts for what I have in mind, but I have to find them.

[Thom]

Two suggestions:

An octagonal shape would continue to aid in alignment while being perhaps more aesthetically pleasing.

If you were concerned about the dards falling out of the back of a rear-loading barrel, 17/32 brass might do the trick (and it has its own benefits, too).

[anders]

I am pretty sure that someone on this forum have done something very similar.
Here

[NerfFreak]

Yours isn't completely homemade. You had to use that factory-made plastic circle. There's a difference.

[anders]

Yours isn't completely homemade. You had to use that factory-made plastic circle. There's a difference.

Do you know how stupid that sounds? Yes I used a factory made plastic circle, but any moron could make their own plastic circle.

[Carbon]

Yes I used a factory made plastic circle, but any moron could make their own plastic circle.

I find it amusing that neither of us chose to do what a moron could accomplish.

Kidding aside, I didn't mean to imply that I was the first to make a turret..I was just testing out the foam seal as a concept. Our two designs are pretty different as a whole (at least, as different as turrets can be).

Redesign is under way; I found some circular off-the-shelf parts that I think will serve a turret purpose pretty well. Moron or not, I have no desire to make my own circle.