Piston Questions

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
User avatar
veginator
Specialist
Specialist
Posts: 186
Joined: Tue Apr 10, 2007 4:02 pm

1. What kind of pressures con a well made piston take?

2. What are the best materials for a piston?

3.How much psi is needed to get the valve into position?

Any replies or comments would be greatly appreciated.
User avatar
DYI
First Sergeant 5
First Sergeant 5
Antigua & Barbuda
Posts: 2862
Joined: Sat Jul 07, 2007 8:18 pm
Location: Here and there

1. Depending on how well made it is, thousands of psi.

2. The best materials for pistons include lightweight, strong titanium alloys, carbon fiber, magnesium, UHMWPE, PTFE, etc...

3. A really good piston can be put into position with less than 1psi.

If you ask vague questions, you get equally vague answers.
Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6572
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

veginator wrote:1. What kind of pressures con a well made piston take?
2. What are the best materials for a piston?

3.How much psi is needed to get the valve into position?
Any replies or comments would be greatly appreciated.
Well made iron cannons, i've read 300 psi.

To many factors to list

To many factors to list.

You kinda have to know what you really want compaired to your abiltys to complete the cannon you have in mind to build.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26219
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 582 times
Been thanked: 347 times

tell us how big you want to make it and what materials you have access to and we can furnish you with more details.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
veginator
Specialist
Specialist
Posts: 186
Joined: Tue Apr 10, 2007 4:02 pm

I want to have a four inch chamber and a 2.5 inch barrel. I have access to any thing you can find at a hardware store for under $100.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26219
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 582 times
Been thanked: 347 times

looks like a 3" endcap is your best option, have a look here?

edit: here, have some energy preditions ;)
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
veginator
Specialist
Specialist
Posts: 186
Joined: Tue Apr 10, 2007 4:02 pm

what would be a good alternitive to noeprene rubber. also what kind of pressures do you think that could take.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26219
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 582 times
Been thanked: 347 times

That can take whatever pressure the pipes and fittings it's made of can take, but it's important to have a bumper between the piston and the back of the chamber to soften the impact.

As to the rubber, there's a few suggestions here.
Attachments
crosmanvalvemod.jpg
hectmarr wrote:You have to make many weapons, because this field is long and short life
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

  • Similar Topics
    Replies
    Views
    Last post