My (hopefully easy and viable) piston design

[Pilgrimman]

If the image doesn't work, forgive me. I've never hosted one on a forum before... I added a link to the host site... although I've never linked on a forum either...

Anyway, the piston is made almost entirely of PVC, except the barrel sealing rubber, and the fill valve. To get a better tolerance between the 1" and 1 1/4", I might wrap it in electrician's tape. The reservoir will be bigger, I just made it small in the image for simplicity. Also, I omitted the pilot valve from the image, as it should be obvious where IT goes...

Thoughts and feedback are appreciated!

Edit: **** neither one worked... Could someone help me???

[/url]http://img403.imageshack.us/my.php?imag ... n9.png[url][/url]

[paaiyan]

<a href="http://img403.imageshack.us/my.php?imag ... ignkn9.png" target="_blank">Link to picture.</a>

I don't really know how all the bbcode stuff works, I use oldschool HTML.

EDIT: I'm not sure I completely understand how it's supposed to work, can you clarify a bit?

[iknowmy3tables]

that may not open cause the sufacearea of presure behind he piston is equal to the barrel size well almost, but the vacum of the barrel in holding it on and their in almost no presure ablible to push the piston back, you have to mesure the forces on both sides based on how much of the area is exposed to presure, the barrel has no presure inside so its side has less

[Gepard]

Code: Select all

 [url]http://url[/url] or [url=http://url]URL text[/url] 

Michael

[spudthug]

so uhh...wheres the chamber going to be

[Pilgrimman]

Everyone look at Paaiyan's link for my image, as I'm too much of an ignoramus to link to it properly

@Paaiyan
Fill it up through the valve, the air pushes the orange foreward, which is the piston. The air bleeds around the orange tube into the blue. Since the endcap on the orange pipe is wider than the pipe itself, in terms of surface area, it SHOULD open when the area behind the piston is piloted. This design is meant for simplicity of construction and low cost, as I have no access to a lathe or other tools.

@iknowmy3tables
The drawing of the endcap on the piston does not really convey it's surface area. The endcaps for the brand of PVC I use are significantly thicker than most. Example: The outside diameter on a 1 1/4" cap of this brand is too much for it to fit down a 2" pipe! That's at least 1/2" inch thick at it's widest point! For this reason, the surface area SHOULD be great enough to overcome the back of the piston.

Thanks to all who responded! I'm going to read more on piston valves, and potentially update my design!

[iknowmy3tables]

its still not big enough unless the endcap is lightly sealed against the 2" pipe, and the 1" in the 1 1/4" is just to guide it then thhere is not enough suface area diffrence from the barrel suface area to operate

[spudthug]

i still want to know where your chamber is going to be and you cant build a gun without a chamber so you should stop asking questions until u figure out where your chamber is...

[lukemc]

i think this should be stickied somewhere Forum code

[Pilgrimman]

@spudthug
The 2" part will probably be longer, and have a reservoir connected to it. I only showed the piston housing and design for simplicity, and the fact that I lack any ability to animate well.

Edit: Thanks to whoever posted the forum code link! Here's my next attempt...

http://img403.imageshack.us/my.php?imag ... ignkn9.png