Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 55 users online :: 5 registered, 0 hidden and 50 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

tennis ball ?'s

Post about things you have launched or thought about launching. Also post about various materials used for building cannons. No posts about explosive projectiles!
Sponsored 
  • Author
    Message

tennis ball ?'s

Unread postAuthor: zach12 » Sun Nov 09, 2008 1:28 pm

there is a store almost a mile from my house that sells 2.5 in. pvc.... but its schudale 80. can i still use that?
  • 0


zach12
Private
Private
 
Posts: 20
Joined: Wed Jul 16, 2008 7:50 pm
Reputation: 0

Unread postAuthor: daberno123 » Sun Nov 09, 2008 1:55 pm

Maybe, but it will be a really tight fit. In SCH 40, the fit is already pretty tight.

You should just take a tennis ball with you to the store and see if you can jam it in.
  • 0

User avatar
daberno123
Colonel
Colonel
 
Posts: 594
Joined: Mon Nov 19, 2007 5:56 pm
Location: Ohio
Reputation: 0

Unread postAuthor: ALIHISGREAT » Sun Nov 09, 2008 2:34 pm

2.5" should be the inside diameter of the pipe, SCH 80 is just the wall thickness.

so a tennis ball should fit in any 2.5" bore tube.
  • 0

<a href="http://www.bungie.net/stats/halo3/default.aspx?player=ALI H IS GREAT"><img src="http://www.bungie.net/card/halo3/ALI H IS GREAT.ashx"></a>
Image
User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: daberno123 » Sun Nov 09, 2008 2:51 pm

ALI, 2.5" is the nominal outside diameter of the pipe. The actual OD is 2.875". Both SCH 40 and 80 pipe have the same OD but different wall thicknesses, and therefore different IDs.

ID of 2.5" SCH 40= 2.445"

ID of 2.5" SCH 80= 2.29"

So a tennis ball may not fit in SCH 80 pipe.
  • 0

User avatar
daberno123
Colonel
Colonel
 
Posts: 594
Joined: Mon Nov 19, 2007 5:56 pm
Location: Ohio
Reputation: 0

Unread postAuthor: zach12 » Sun Nov 09, 2008 3:25 pm

a really tight fit is good. right?
  • 0


zach12
Private
Private
 
Posts: 20
Joined: Wed Jul 16, 2008 7:50 pm
Reputation: 0

Unread postAuthor: ALIHISGREAT » Sun Nov 09, 2008 3:57 pm

daberno123 wrote:ALI, 2.5" is the nominal outside diameter of the pipe. The actual OD is 2.875". Both SCH 40 and 80 pipe have the same OD but different wall thicknesses, and therefore different IDs.

ID of 2.5" SCH 40= 2.445"

ID of 2.5" SCH 80= 2.29"

So a tennis ball may not fit in SCH 80 pipe.


Really? in the UK, imperial pipe sizes always refer to the nominal bore, so 2.5" means a 2.5" bore, then our metric system refers to the OD, so 75mm pipe is 75mm OD.

it appears you are right :wink: http://www.engineeringtoolbox.com/pvc-cpvc-pipes-dimensions-d_795.html
  • 0

<a href="http://www.bungie.net/stats/halo3/default.aspx?player=ALI H IS GREAT"><img src="http://www.bungie.net/card/halo3/ALI H IS GREAT.ashx"></a>
Image
User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: Velocity » Sun Nov 09, 2008 4:13 pm

zach12 wrote:a really tight fit is good. right?


A loose fit is bad, because air can rush past the projectile, hurting efficenticy

A tight fit is bad, because friction will greatly slow down the speed of your projectile

You are looking for a firm fit. In my opinion, the fit of a tennis ball in 2.5" SCH 40 is the tightest fit that is still acceptable. 2.5" SCH 80 will be way too tight, and in fact, probably won't fit the tennis ball at all. Look for 2.5" SCH 40.
  • 0

User avatar
Velocity
Brigadier General
Brigadier General
 
Posts: 1039
Joined: Tue Feb 07, 2006 5:42 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: starman » Sun Nov 09, 2008 5:20 pm

Yep sched 80 2.5 won't work...go sched 40 2.5. Also, as you shoot tennis balls, especially with a combustion, the fuzz will wear or burn down and they will fit in the barrel a little easier.
  • 0

User avatar
starman
Donating Moderator
Donating Moderator
 
Posts: 3041
Joined: Wed Dec 12, 2007 12:45 am
Location: Simpsonville, SC
Reputation: 0

Return to Construction Materials/Ammo Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'