Who has drozd type full-auto BB gun? It's going inside a UAV

[kiwi of nitro]

Hi,

I like to build FPV aircraft and I've equipped them with rockets before, but never a full auto cannon of any sort...

I need to know how much the DROZD type guns can be stripped down (to shed weight and size) I plan to wire the firing circuit directly into my onboard receiver via a couple R/C relays. I will be able to toggle through firing settings and fire the gun electronically from my transmitter. I will most likely use a high wattage green laser plus a cross-hairs on my OSD (on screen display) to aim.

I have a pusher style propeller on this aircraft so the barrel will protrude right under the nose, below my camera (which is on top of the nose). The rest of the gun will be arranged within the (cramped) fuselage.

The gun will have to shed it's housing, and keep only the bare firing circuit, solenoid, clip, barrel, hammer valve assembly and Co2 cartridge, plus enough of the housing or maybe I'll make a new housing to hold these parts together inside the fuselage. EVERYTHING ELSE NOT NECESSARY FOR FIRING MUST GO.

I don't own one of these guns yet so I don't know whether this will work, I'd like to hear from someone who has a DROZD as to how much the can be stripped down before I buy one.

I might end up making my own gun... However I would MUCH prefer to just buy this one and make it work.




[youtube][/youtube]

Here's a video of a common FPV ship and the RVOSD v2.01 onscreen display. In case you haven't a clue what I'm talking about.






Most FPV setups looks something like that...

[Technician1002]

Hi,

I like to build FPV aircraft and I've equipped them with rockets before, but never a full auto cannon of any sort...

Most FPV setups looks something like that...

I don't know much about the gun, but the display pinpoints the location very nicely. Plug this into google maps to see the launch site.
46.797348 -96.02232. This was shot in Minnesota USA near the town of Audubon. Launch site is between Leaf lake and Little Comorant Lake.

[POLAND_SPUD]

all I can say is - WOW

now I think that these things are so advanced that they might be dangerous... just think how easy it would be to convert it into a homemade cruise missile

[kiwi of nitro]

You could almost call this guy's flying a little dangerous... But he's got to be the best fpv pilot on earth.

[youtube][/youtube]



This diagram shows what may be the next generation of FPV flying, right now wi-fi and encoding isn't used, video is analog.




And what's so scary about cruise missiles? they're lots of fun!

http://www.interestingprojects.com/crui ... iary.shtml

[jackssmirkingrevenge]

I might end up making my own gun... However I would MUCH prefer to just buy this one and make it work.

This would seem like the best idea - a cloud type BBMG with an electronically actuated valve would be a good equivalent. You don't even need high pressure air, a couple of soda bottles would make good lightweight tanks capable of holding 100 psi or so. Heck, you could even make a PVC tube fuselage that is also the airtank. Incorporating the air supply into the structure instead of as a separate entitity will surely save weight. As a valve, you might want to consider a small diaphragm valve from a dishwasher/washing machine like this one.

Also, why have a forward firing gun when it could poke out the side

[youtube][/youtube]

edit: JSR^TM - giving you consistent advicesince 2007

[kiwi of nitro]

I can add about 250g to this aircraft without suffering too much of a performance loss, my brushless system's thrust MATCHES the weight of my airframe at 75% throttle! The reason I don't like the cloud chamber is because of the decreased accuracy, power and efficiency, it has a higher rate of fire, but it will weigh more and take more space from batteries/fuel and electronics. I'm looking for a system that can be controlled precisely & electronically and my idea is to be able to shred a target as small as a soda bottle with a 3 rd. burst while flying 3ft off the deck at 70mph.

100psi is nothing compared to the 850psi in the more compact 12g co2 cartridge.

Mainly I really like the drozd's firing control board, using a few RC relays I can plug that right into my flight control receiver and toggle firing settings from the ground using an extra channel and 3 position toggle.


The structures of my aircraft are carbon fiber sheeted with polyurethane or a glass fiber and carbon cloth saturated in epoxy and adhered to the carbon fiber or carbon composite structure light ply and high density foam is also used but PVC is not good for an airframe that is capable of high-G maneuvers.

I have lots of reasons for the forward firing gun, At 70mph my airspeed will add 100fps to the drozd's velocity, making it 540fps... Plus I would like to make use of the drozd's rifled barrel, I'll have much less accuracy with a side firing gun. I want to sight the gun up with a cross-hairs on my display, this way I can deliver precise onwage to targets ahead of the aircraft.

If I wanted to make a serious combat drone, I would put the drozd on a linear pan and tilt with the camera, then I could aim in any direction using my gyroscopic head-tracker (pan&tilt controlled by pilot's head movements). Rather than just have the cross-hairs lined up with the gun only when the camera's pan and tilt was in the neutral forward facing position.


I'm going to mount it A-10 style

[jackssmirkingrevenge]

The reason I don't like the cloud chamber is because of the decreased accuracy, power and efficiency, it has a higher rate of fire, but it will weigh more and take more space from batteries/fuel and electronics.

At 100 psi, a cloud with a reasonably sized chamber (say enough for 200 BBs) will match the standard drozd for power. As to accuracy, you're firing unrifled BBs either way, I doubt one is better than the other. The standard drozd only has 30 rounds on board, so that's hardly efficient. If you use lightweight chambers like Soda bottles I think the all up weight will be better than the drozd. There's no way you're going to have a functional drozd at 250 grams down from the original 1600 grams.

I'm looking for a system that can be controlled precisely & electronically and my idea is to be able to shred a target as small as a soda bottle with a 3 rd. burst while flying 3ft off the deck at 70mph.

That sounds a bit unrealistic to me, accuracy is not going to be out of this world so if it were me I would try to make up for it with weight of fire.

100psi is nothing compared to the 850psi in the more compact 12g co2 cartridge.

More compact and fairly heavy, considering the beefy metal structure that needs to contain it. I've managed to get 400 fps with steel BBs from a 100 psi BBMG, that's better than the factory spec of 360 fps for the drozd.

Mainly I really like the drozd's firing control board, using a few RC relays I can plug that right into my flight control receiver and toggle firing settings from the ground using an extra channel and 3 position toggle.

That I can't argue with, but maybe you could build a similar burst fire device from scratch.

The structures of my aircraft are carbon fiber sheeted with polyurethane or a glass fiber and carbon cloth saturated in epoxy and adhered to the carbon fiber or carbon composite structure light ply and high density foam is also used but PVC is not good for an airframe that is capable of high-G maneuvers.

I'm sure a length of PVC pipe would make a perfect fuselage in terms of strength (though perhaps not weight), you're hardly going to apply enough G-force to snap it.

I have lots of reasons for the forward firing gun, At 70mph my airspeed will add 100fps to the drozd's velocity, making it 540fps... Plus I would like to make use of the drozd's rifled barrel, I'll have much less accuracy with a side firing gun. I want to sight the gun up with a cross-hairs on my display, this way I can deliver precise onwage to targets ahead of the aircraft.

Ah, you'll be aiming with a camera display? Maybe you'll get a bit more accuracy then but the drozd's rifled barrel is completely irrelevant for steel BBs, they are too small (4.4mm) to grip the rifling and indeed you get plenty of blowby through the groves, reducing efficiency.

[inonickname]

How much power do you need? You could research into mechanical guns such as the dread if it's just to impress people/practise etc.

Though I love the idea.

[psycix]

I'd also use a cloud/vortex BBMG. Being able to "draw a line" makes it way easier to hit a target.
What about some carbon fiber/glass fiber body which is also the air tank?
Mount the barrel coaxial with an electronic valve and BB hopper on the breech end.
If the air tank is strong enough to hold the pressure but isn't airtight, maybe insert a balloon or something.

[jackssmirkingrevenge]

What about some carbon fiber/glass fiber body which is also the air tank?

I proposed PET soda bottles as a cheaper alternative but obviously this would be a better solution if you had the resources.

I believe the best option is to incorporate the air tank in the structure, interesting to note that when pressurised considerable rigidity is added.

[kiwi of nitro]

Ah, you'll be aiming with a camera display? Maybe you'll get a bit more accuracy then but the drozd's rifled barrel is completely irrelevant for steel BBs, they are too small (4.4mm) to grip the rifling and indeed you get plenty of blowby through the groves, reducing efficiency.

YES! I'll be aiming with the cross-hairs on my ON SCREEN DISPLAY through a video headset!

The drozd is not supposed to fire steel BBs it is only for lead BBs steel will wear it out. I've heard the gun fires 440fps consistently, 540 with the airspeed added on.

I think I can strip the drozd down to make it meet the constraints of my airframe. I've heard the CLIP contains the hammer valve, ammo and co2, just the solenoid, barrel and firing circuit is left in the housing. The drozd has weight added to make it more realistic as well.

Here's a close picture of an OSD, notice the cross hairs I will use to aim.


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[Technician1002]

Can you tell me a little about the GPS coordinates on the OSD? They are not showing the true location of the plane. That does not look like the street next to a baseball diamond. Is that a way point for autopilot?

[kiwi of nitro]

I don't know I found that pic on google, it's not the RVOSD, I think those are the coordinates of the base station.

[kiwi of nitro]

Most common GPS module...

http://www.rangevideo.com/index.php?mai ... cts_id=182

[jackssmirkingrevenge]

[YES! I'll be aiming with the cross-hairs on my ON SCREEN DISPLAY through a video headset!

Sorry, I had gone into the projectile firing nitty gritty completely bypassing the whole "FPV" affair

I think I can strip the drozd down to make it meet the constraints of my airframe. I've heard the CLIP contains the hammer valve, ammo and co2, just the solenoid, barrel and firing circuit is left in the housing. The drozd has weight added to make it more realistic as well

Pretty much:



Still, that's only 30 rounds capacity, and frankly I doubt you're notice the difference between a rifled and unrifled barrel. I would still go for a scratch built flying airtank with a BBMG hooked up to it, the rate of fire and magazine capacity will make it a lot more viable as an aerial gun platform, and by using the air tank as a structural member there's much less of a weight penalty incurred.