Drozd type of bb gun

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
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Antonio
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Thu Jan 03, 2008 5:27 am

This gun works with a sleeve valve. Once the valve is hit at the back with a solenoid, the valve moves forward taking a bb with it. When it is far enough forward the valve gives a burts of air and shoots the bb. The valve closes and the whole process can begin again. Like this u can get semiauto/auto fire which is very controlled due to the use of a solenoid. At the moment I am working on making this gun feasable. The only problem for me is that the valve stem cant move that freely through the o-rings.


The valve I made according to this design
Image
Plz see homemade valves for more info.
Attachments
Magazine cutaway.
Magazine cutaway.
co2mag makarov.jpg (16.54 KiB) Viewed 13803 times
Drozd bases
Drozd bases
drozddiag.gif (36.12 KiB) Viewed 13803 times
Outside
Outside
cat911.jpg (18.14 KiB) Viewed 13796 times
Magazine again
Magazine again
AK-Mag-web.jpg (17.59 KiB) Viewed 13796 times
Drozd side shot. With view of the valve system. So simple but so great!
Drozd side shot. With view of the valve system. So simple but so great!
DrozdValveGif.png (10.46 KiB) Viewed 13172 times
Last edited by Antonio on Sat Jan 26, 2008 5:33 pm, edited 6 times in total.
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f.c
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Thu Jan 03, 2008 5:39 am

wow that looks quite advanced. **waits for jsr**
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)DEMON(
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Thu Jan 03, 2008 5:58 am

The same sort of valve is used in a lot of co2 pellet pistols. It is a fairly simple hammer valve, incorporated into the mag.

Good luck building this valve, it will be difficult with the small diameter holes you need to drill.
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jackssmirkingrevenge
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Thu Jan 03, 2008 6:10 am

)DEMON( wrote:The same sort of valve is used in a lot of co2 pellet pistols. It is a fairly simple hammer valve, incorporated into the mag.
The difference is that the Drozd uses a solenoid hammer, not spring-loaded like normal CO2 pistols. This means that it can be set to fire to single shots or full auto in bursts, controlled precisely by fiddling with the electronics.

Ant, trying to replicate this for CO2 would need very precise machining to contain the valves. Are you planning on using it full auto with a solenoid or manually cocked semi-auto?

The mechanism is conceptually identical to what I had proposed here.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Antonio
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Thu Jan 03, 2008 7:03 am

jackssmirkingrevenge wrote:
)DEMON( wrote:The same sort of valve is used in a lot of co2 pellet pistols. It is a fairly simple hammer valve, incorporated into the mag.
The difference is that the Drozd uses a solenoid hammer, not spring-loaded like normal CO2 pistols. This means that it can be set to fire to single shots or full auto in bursts, controlled precisely by fiddling with the electronics.

Ant, trying to replicate this for CO2 would need very precise machining to contain the valves. Are you planning on using it full auto with a solenoid or manually cocked semi-auto?

The mechanism is conceptually identical to what I had proposed here.

Hey thnx I had not seen ur post before. Ill post some pics of the valve I made. But as i said it has too much friction due to the tight fit> I think u had the same problem in ur project. I will try to sanddown the bolt'' to the right size and then c if it works.
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experament-u2
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Thu Jan 03, 2008 6:45 pm

i just found this ant thought it might help

i never realized the hammer and all that was part of the mag that is brilyant
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TwitchTheAussie
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Thu Jan 03, 2008 7:17 pm

Looks like another illegitimate child of JSR's has popped up. Good thinking tho it confuses me too no end with all those diagrams but I get the concept.
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jackssmirkingrevenge
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Fri Jan 04, 2008 12:27 am

experament-u2 wrote:i never realized the hammer and all that was part of the mag that is brilyant
It's a bit like the magazine in my yunker, the magazine containts the hammer, valve and effectively can be fired while out of the gun.
Looks like another illegitimate child of JSR's has popped up
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hectmarr wrote:You have to make many weapons, because this field is long and short life
jon_89
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Fri Jan 04, 2008 1:16 am

so is the bb shot with the spring or the co2?
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jackssmirkingrevenge
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Fri Jan 04, 2008 1:26 am

The solenoid hits the purple valve section, which pushes a BB into the barrel and releases a burst of CO2, which fires the BB. The spring then returns the the valve, closing off the CO2 and allowing a new BB to be pushed in place.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Antonio
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Fri Jan 04, 2008 3:33 pm

experament-u2 wrote:i just found this ant thought it might help

i never realized the hammer and all that was part of the mag that is brilyant
Hey man thnx so much! I was looking/searching for this pic for a long time. I got how the gun worked but this makes it all more visual. I couldnt read those russian sites where it was on so I could never find the real gif.
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Antonio
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Fri Jan 04, 2008 3:39 pm

[quote="jackssmirkingrevenge
It's a bit like the magazine in my yunker, the magazine containts the hammer, valve and effectively can be fired while out of the gun.
[/quote]




The picture that I posted is from the Yunker AK 47 I think. As I couldnt find a good picture of the magazine I used that one. But yeah its all the same. Jack u should check out the new post I placed on valves. The third valve is one like in these the magazines. I noticed that u can tighten the fit'' by pressing on the copper orings holders. Like this you can get the right tension'' for low friction on the hammer but still 100% sealage.

[quote="jackssmirkingrevenge
Ant, trying to replicate this for CO2 would need very precise machining to contain the valves. Are you planning on using it full auto with a solenoid or manually cocked semi-auto?
/quote]

I dont work with CO2 rather with air, not sure if that makes a difference. I just bought a new aircompressor (8bars). I am first planning to make it recock manually as I am not that good in electronics. But I have tried this other valve (valve 2 in my recent post) with an electric doorbell spool and pin before. It worked really nice. In this case I will need a stronger spool with more displacement, that could be a problem. At the end I will try to make it semiauto using the solenoid or using a part of the air that comes from the valve. I think this valve is better for autorecocking as you dont need to overcome so much force to open the valve (like in poppet valves). In previous tests I have seen that as my valve head is about the size of my tubing; the pressure that comes outof the valve is about the same. This means that I have to increase the surface area of the bolt by more than twice the valve head area inorder for autorecocking. But then the problem arises that my dwel time is too short. etc etc lol
Last edited by Antonio on Fri Jan 04, 2008 3:54 pm, edited 1 time in total.
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Acdcmonkey1991
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Fri Jan 04, 2008 3:47 pm

If you want I have an old crosman mag that works exactly like this that I don't want... pm me if you want it
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SPG
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Sat Jan 05, 2008 10:26 am

Ok so dumb question..... how's the gas get to the barrel? I can see how the BB does, but the gas?

In this picture

Image

I presume the solenoid taps on part 4, which moves forwards compressing spring 6 and also loading a BB. But how does the gas get round part 4? or is part 4 craftily tubular and complicatedly made?

The perk to a solenoid operated valve like this for us I've always thought is that we could put the solenoid inside the pressure vessel too. One of the things I think we have a lot of difficulty replicating is the tight tolerances need for effective sealing. Put the solenoid inside the chamber and you only have to seal the two wires coming out, which is a lot easier.

Now can anyone build a circuit board to replicate the drozd's?
Hawkeye
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Sat Jan 05, 2008 10:45 am

The coloured diagram shows diagonal lines through the wider section of the valve which probably indicates a channel that runs from the back out the front, directly behind the BB. The wider section of the valve would be hollow.
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