Cloud bbmg barrel and air input position questions.

[Boomer58cal]

I'm experimenting with several bbmg designs and I have some questions. After much research I've yet to find any discussions about how far inside the chamber the barrel should go on a cloud design. I've seen designs with the barrel barely into the chamber and I've seen some where the barrel went almost to the back of the chamber.

Well...which is the best?

I would also like to know if anyone has found the optimum barrel to air input position. Basically I'm just curious if anyone had found the best spot for the air to enter the chamber. I've seen them toward the front of the chamber and the breach end of the barrel toward the back of the chamber. I've also seen the air input directly below the breach end of the barrel.

Has anyone found that one configuration seems to work particularly better than another configuration?

Thank you for any insight you may have, I just wanted to ask the knowledgeable people here before I built three or four chambers to experiment with. This particular one will use airsoft ammo and a piece of brake line for the barrel. For my final design I'd like to use a real airsoft barrel.

[jackssmirkingrevenge]

Frankly as long as the barrel sticks out a little into the chamber, and the air flows into it in such a manner that it directly agitates the main mass of BBs, it doesn't really make a difference.

Here is basically what is happening in slow motion:

[youtube][/youtube]

[Boomer58cal]

That's exactly what I wanted to hear! Like always Sir you are a wealth of knowledge. Thank you.

Well then mostly I'll have to experiment with the chamber and air supply volume. I have an old backpacking frame I'm going to turn into a portable air supply. I have a bunch of 3" sch 40 laying around. I'm going to start with about a gallon and a half or two gallons at 100-120 psi and see what kind of run time I get. I will test it with my smaller 3 gallon air compressor at 100 psi and start from there. I think that will give me a good idea of how large of air supply I need. I may add a pressure regulator to allow me to trade runtime for power and vice a versa. I would like to get 20+ seconds of runtime. Of course more is always better.

I also have 6 small 3000 psi o2 tanks but I haven't been able to find a regulator set up that fits them.

Thanks again.

Edit... Well I tested my prototype. It feeds great but accuracy isn't what I would call spectacular by firearm standards. For airsoft it probably good enough. The rate of fire is much slower than my tube feed .177 bb gun, but this one will sustain fire for much longer.

[jackssmirkingrevenge]

you might want to consider a valve with better flow for greater rate of fire and muzzle velocity, a small 1/4" solenoid valve is cheap to find and will dramatically improve performance.

Jimmy got some good results: http://www.inpharmix.com/jps/diaphram_valve_BBMG.html

[Boomer58cal]

A better valve is definitely in order. This was mostly built with scraps. I'm going to test this out tomorrow ( because my propane tank is empty today )

[NeoSpud]

That's exactly what I wanted to hear! Like always Sir you are a wealth of knowledge. Thank you.

Well then mostly I'll have to experiment with the chamber and air supply volume. I have an old backpacking frame I'm going to turn into a portable air supply. I have a bunch of 3" sch 40 laying around. I'm going to start with about a gallon and a half or two gallons at 100-120 psi and see what kind of run time I get. I will test it with my smaller 3 gallon air compressor at 100 psi and start from there. I think that will give me a good idea of how large of air supply I need. I may add a pressure regulator to allow me to trade runtime for power and vice a versa. I would like to get 20+ seconds of runtime. Of course more is always better.

I also have 6 small 3000 psi o2 tanks but I haven't been able to find a regulator set up that fits them.

Thanks again.

Edit... Well I tested my prototype. It feeds great but accuracy isn't what I would call spectacular by firearm standards. For airsoft it probably good enough. The rate of fire is much slower than my tube feed .177 bb gun, but this one will sustain fire for much longer.

Your "run time" on just a few feet of pipe carried as a backpack won't be good; it certainly wouldn't be enough for an airsoft game or skirmish. The cloud design is really best for compressor-based firing, and honestly is just the starting point when it comes to BBMG design. Without a doubt it's cool as hell and you should be proud for making one, but as soon as you get it working you should be striving to make another one that makes up for all the limitations of the cloud design! A basic vortex, whether outline or inline (yes, I am biased towards inline lol) should be your next step, and if you want to use this design in airsoft battles then you should start to save up for the required materials: a CO2 tank and low pressure regulator.

Kudos on being where you are, and much encouragement to where you eventually will be!

[jackssmirkingrevenge]

if you want to use this design in airsoft battles then you should start to save up for the required materials: a CO2 tank and low pressure regulator.

If you want to murder your friends, a HPA tank and no regulator

[youtube][/youtube]

[Boomer58cal]

Thanks for the input.

The backpack will also be used for a Uber-soaker I'm making to assault the neighborhood children this summer, so it won't be a wasted effort. It will be five 3"x24" sch 40 tanks, roughly 3.67 gal. or 848 ci. That should be enough to flame thrower a bunker. Weight is not an issue, I'm 6'4" 280 lbs.

A regulated HPA setup is waiting in the wings. I just have not been able to find a regulator that will fit my O2 tanks. They are the little ones, about a foot tall and 2.5" in dia.

Yes V-block is next on the list. I'm just not sure my skills on the leith are up to par yet, but I have a half a dozen small blocks of aluminum that are just the right size for a V-block, so I can screw up a couple of times. It would be a good learning experience for me. Although I may just start simple and make one on the drill press. That I can do.

Hopefully I'll get a chance to test it out on propane power later today. I have a feeling the propane tank will outlast the backpack, but won't have quite the power due to the nature of propane. It rarely gets over 80 degrees where I lived and propane expands rather slowly.

[Boomer58cal]

Ok so I've been promising some videos. I've spent the last two months trying to upload to YouTube! I don't know what changed but it worked today. Here's one to start. About 500 rds in around 10 sec. from a 3 gal. 100 psi tank. 90 psi at the gun. I need to build a larger chamber for more ammo capacity when I get the backpack done. I had about 70 psi left in the tank when I ran out of ammo. With 120 psi in my backpack, regulated to 80 or 90 psi, I think I can get a full 15 seconds with a slightly larger chamber. That should be good enough for a game with my MP5 for backup.

[youtube][/youtube]

Edit... Sorry I just realized in the excitement of finally posting a vid I committed the cardinal sin of double posting! Won't happen again. I stand ready for my 10 lashings.