Conceptual Drawing

[SNDM]

Im having a go at an automatic.
I have a lathe, Mill and experiance to boot.

I've planned it as the diagram.
Basically I was wondering wether people could see any faults,
and wether people could see it working.

Its pretty simple, absolutely nothing new.



The cycles are started by depressing the hammer valve pin.
I hope for pressure to build up in the elbow as it pushes the bolt and strong spring.

Thanks for the input!

[Sticky_Tape]

won't work the hamer valves give short blasts of air in small volumes so having high dead space will make it not work.

[SNDM]

That is why you hold the pin down, made easier with a levered handle.

I cannot see how that wouldnt work.
It would keep it open.
The hammer valve is held open to allow compressed air to fill up the shot chamber (the elbow).

[Sticky_Tape]

why not just ude a blowgun esencially they are hammer valves and they already have the lever.

[SNDM]

I:

• Don't have one.
  Can't be bothered finding the fittings. (on that note, what are the threads?)
  Want one with better airflow.
  Can build one myself.
  Can house it in tee piece to make it look neater.
  Like my own work, when it isn't crap. (Actually I like any work that isn't crap.)

Questions?

[pizlo]

I:

• Don't have one.
  Can't be bothered finding the fittings. (on that note, what are the threads?)
  Want one with better airflow.
  Can build one myself.
  Can house it in tee piece to make it look neater.
  Like my own work, when it isn't crap. (Actually I like any work that isn't crap.)

Questions?

1. They are 5 dollars and stocked at every homedepot or lowes I've ever been to.
2. See above^^ Mcmaster carr also carires them at around 4 dollars and has fast shipping.
3. a modded husky blowgun is going to be hard to beat.
4. Great Reason
5.That willl be hard!
6 Another good reason.

I'm no the peron who would tell you whats wrong with the design. listen the sticky, and others. They really do know what they're talking about. And If you have a Lathe and Milll I expect to see some sick guns from you!
And Tape is realy right, that deadspace will ruin performance.

[THUNDERLORD]

I enjoy the blow forward bolt designs.
The valve looks interesting.
What do you plan to build it out of?
What do you plan to shoot?
What size will it be? (Handheld or?)

I've been working on a cannon with a T configured similarly because it lowers the stock for better view of the sights.

BTW mine has a sprinkler valve where your design has the blow forward bolt, and the chamber runs from both sides of the T, The back section is threaded coupling for shorter configuration/take down to about 15inches.
Much different functionally, but the actual design shape is nice. 8)

@Pizlo, OOoops, I was typing still when you replied, or I wouldn't have replied so soon
Dang, When Pizlo write a longer reply it's really something to pay attention to also.
(Because Some of the most intelligent short replies I see here are written by him)!

[SNDM]

I live in Scotland, which voids the McMaster/Lowes/Home Depot thing.
I have no knowledge of Husky blowguns, so I cant really say anything abouit that.

Ok, I thought that the deadspace would work well as a chamber for each shot, but Im prepared to rethink that if it wont function as I want it.

@THUNDERLORD

Fittings and Pipe
15mm: Copper
10mm pipe: Thinwall Brass

"Hammer" valve:
Stainless Steel

Bolt:
Plastic

To shoot:
Err... I dont know any sizes of BBs in mm.
Anything thats cheap, in plentiful supply, that fits well in the barrel.
(I'll probably need some ideas on this.)

Size:
A combination of 15mm and 8mm pipe.
As compact as I can.
The stainless steel for the "hammer" valve had to be turned down for the copper tee. (I had to take out some of the copper tee that prevents the pipe going to far.)

I have done some of this.
The bolt is done, I just need a spring, and I need to drill a holl in the Hammer valve and finish the pin.
Then I get to assemble it all.

[jackssmirkingrevenge]

It's basically exactly the same principle as my 6mm semi, I see no reason why it shouldn't work. My one recommended change would be to have the barrel as one piece though the tee where magazine fits with a slot cut in to feed the ammunition, to reduce the possibility of jams.

[SNDM]

Ok, Ill fill in spaces in the tee, to keep a smooth supply.

*runs off to the lathe*

[SEAKING9006]

As for a spring, McMaster is the best place I've ever seen to get them. They use an on line order form, so your location shouldn't be an issue. Just make sure you calculate the force exerted on the piston correctly so you get the right spring for the job. For example, on my blow forward the pressure is exerted on the entire rear face of the piston which will be sealed with epoxy, so I used the O.D. of the pipe to determine the piston area, and then multiplied that by different pressures. For yours, I suggest the same thing.