P. 3 Stacked tube

[rna_duelers]

I love it.Small pneumatics aren't a favorite of mine but I do like this a lot.With a little bit of money and time you could make some impressive guns no doubt.Hope to see more out of you yet!

[Antonio]

I love it.Small pneumatics aren't a favorite of mine but I do like this a lot.With a little bit of money and time you could make some impressive guns no doubt.Hope to see more out of you yet!

Hey thnx man! Yeah small pneumatics can be really annoying due to all the fitting etc. But it is a good project which doesnt need lots of money nor tools. The materials costs around 12$, and simple tools like a dremel, a soldering burner'', and a drill machine with some drill bits. It will take some time for me to share my ideas over the automatic airguns. I am looking at the design of the tippman and the spyder and a new reversed (mirrored spyder) which uses the barrel as the bolt.

[Strake]

absolutely love how this works i might give something like this a try for my next one but bigger scale.

[fretmelter]

i like how u took the whole spyder design and used it for small projectiles but i have some questions. How many shots do u get off of tht air suply and how much psi is in it. Also did u use a sear to firer your hammer or did u make something els. also i was thinking of using other paintball gun designs like the autococker not much different from spyder, besides its closed bolt. what did u make your hammer out?

thnx im attempting a similar project

[Antonio]

i like how u took the whole spyder design and used it for small projectiles but i have some questions. How many shots do u get off of tht air suply and how much psi is in it. Also did u use a sear to firer your hammer or did u make something els. also i was thinking of using other paintball gun designs like the autococker not much different from spyder, besides its closed bolt. what did u make your hammer out?

thnx im attempting a similar project

The airgun shoots about 30-40 times on a 1.5 liter bottle at a operating pressure of about 5atm (using a bicicle pump> nothing fancy). To release my hammer I made a whole trigger setup just like the spyder paintball gun. http://www.ultratwistedpaintball.biz/mm ... ation.gif

I did try to make an autococker before, but it made the gun very inefficient in air and loading via a magazine was very difficult as well due to jamming. I have read some stuff about open and closed bolts, and that the effeciency is not much different between ehm. Btw my gun is closed bolt bc when u pull the bolt back it cocks and pulls the barrel back (thus closes the loading hole), when fired the barrel moves forward due to the airfriction on the inner side with the air and reopens the ball port''.
I will get some more detailed pictures on these parts as its hard to explain:)

Further the hammer/bolt is made out of an aluminium tube as seen on the picture, with a nail in it (so it blocks up the hole). This is a bit of a problem as the holes in the aluminium where the nails goes through tends to get bigger due to the force of hitting the valve. I also found out that a heavier steel bolt/hammer is more efficient. I have done some dynamic calculations on this before, but I think trial and error with different spring constants is easier. It is too hard to calc the friction between the tubes and the time the valve is open, this all makes it very hard to find the optimum setup''.

[Antonio]

absolutely love how this works i might give something like this a try for my next one but bigger scale.

Yeah bigger scale could be great! Keep track of hammer mass and valve spring constant though. A too weak spring or a too heavy hammer may result in efficient working (too much air used up). A too strong spring or too light mass has the opposite effect ofcourse. As I dont use a regulator on my system I use a big air tank (1.5l coke bottle) instead to make the air pressure as constant as possible over mulitple shots.

[Strake]

thanks mate. was this your own design?? how long did it take you to build this?

[Antonio]

thanks mate. was this your own design?? how long did it take you to build this?

I have been working a long time on these airgun already. My first design was a waterbottle with a popcap that opens when u move it forward (the one from the drinking bottles), it was really powerfull but only had one shot. I started working on new designs and came up with the barrel bolt concept as seen on my other project. This stacked tube design is taken from the spyder type of paintball guns as I saw that they had optimum designs. Inorder to make it though I had to use past experience and knowledge from making valves and mechanisms used for airguns. I have know about this forum before, but never found anything like it. Eventhought the spyder paintball guns (stacked tube) are really famous''. The thing is, u can look at a paintballs design but it is always a challange to make something like it but then with the materials and tools that I have. So yeah to be honest it took me 5 years to get to this gun, ofcourse not working on it constantly, rather step by step. If you know how to make things like this and if you look at my pictures, it could take u up to a weekend. Some things have to be tried out, like the use/making of different valves. I think I have made a easily reproducibil valve now. So I use is on all my designs. I think that is the first step u should make: making a poppet valve. Things like magazines and fancy looks come later

[Strake]

ive got plenty of time now thanks to the holidays so im either going to try to build a valve like this or the one i drew up. i want everything to be hand made on this airgun im building. i most probably will try to make both and see which works the best and keep that.
once again good job

[Antonio]

ive got plenty of time now thanks to the holidays so im either going to try to build a valve like this or the one i drew up. i want everything to be hand made on this airgun im building. i most probably will try to make both and see which works the best and keep that.
once again good job

Hey if you are making ur own valve check my new posting:
homemade valves

[jon_89]

are shots consistant or do they with each shot?

[jackssmirkingrevenge]

Techincally, as you shoot, the pressure goes down (meaning less power) but the resistance on the valve is also less, meaning it opens for longer (more power) so there should be a reasonable level of consistency.

[jon_89]

hey ant you know what would be really nice? maybe post a how to on this gun.

[Antonio]

Techincally, as you shoot, the pressure goes down (meaning less power) but the resistance on the valve is also less, meaning it opens for longer (more power) so there should be a reasonable level of consistency.

Thats exactly correct. As thought I have done measurements of speed decrease over shots, and it does go down eventhough the dwell times go up. I guess bc the barrel has a certain length and a longer dwell time has no effect. I have this graph here of the stacked tube airgun (check attachment). I am not sure what bottle I used on this test though, 0.5L or 1.5L I also did this test before I had a compressor so I dont know the pressures I used.

hey ant you know what would be really nice? maybe post a how to on this gun.

Hey yeah I know, but I am focusing on more simple guns posting whise as I think ppl should first get going on making a valve who are interesting in this project. This airgun looks good and is veeery efficient but its recocking system is slower then the other guns i made. I was ganna try to make this one auto just like spyder paintball guns. But this doesnt really work out due to leakage of the hammer. So yeah my advice is to look at my other projects and start of a bit easier. As I live in a othercountry as well I dont know what is available in other countries.
Btw if u are really into this airgun just look up on P.4 what materials I used (same ones for all projects) and then look at the pictures I posted how I put it togethor. Thnx for ur interest btw

[st.croixsurfer]

At the moment im currently reproducing this on a larger scale think. [m1 garand]