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 66 users online :: 4 registered, 0 hidden and 62 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

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

The Team
Administrators
Global Moderators
global_moderators.png CS

Wrinkled ductape on piston

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: mark.f » Sun Sep 16, 2007 8:16 am

How close is the piston diameter to the pipe inside diameter?

I've found that if there's only a tiny bit of space and you use only a layer or two of duct tape, it tends to get wrinkled up because moisture from the compressed air can get into the adhesive easier.

I used 1-7/8" PVC rod for my piston, and wrapped it in several layers of duct tape to fit. As for lubrication, I used normal petroleum jelly. Works fine and doesn't eat away the duct tape too bad.
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: jrrdw » Sun Sep 16, 2007 8:26 am

The piston should slide in the aluminum.
The reason the piston shouldn't be wrapped is because if the aluminum slides in the cylinder it would chew the cylinder walls up.
  • 0

Last edited by jrrdw on Sun Sep 16, 2007 8:30 am, edited 1 time in total.
When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6538
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: noob of noobs » Sun Sep 16, 2007 8:27 am

Without duct tape, there's probably less than 1/8" clearance. It only took about one wrap of duct tape to make it tight.

EDIT: So then do you epoxy the aluminum to the inside of the piston carrige?
  • 0

User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

Unread postAuthor: jrrdw » Sun Sep 16, 2007 8:31 am

noob of noobs wrote:Without duct tape, there's probably less than 1/8" clearance. It only took about one wrap of duct tape to make it tight.

EDIT: So then do you epoxy the aluminum to the inside of the piston carrige?


Yes, read the edit to the above post.
  • 0

When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6538
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: noob of noobs » Sun Sep 16, 2007 8:40 am

That's a good idea. I'll try that as soon as I have time.
Thanks.
  • 0

User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Sun Sep 16, 2007 9:31 am

noob of noobs wrote:My parents are divorced.


sorry to hear that, apologies if that wasn't funny.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: noob of noobs » Sun Sep 16, 2007 1:45 pm

No, it is funny. I was joking by the way. :lol:
Also, do you think it would be possible to tape the aluminum or use regular glue instead of epoxy? I'm not very good with epoxy to say the least... :oops:

EDIT: They're not divorced, but they don't spend much time together either.
  • 0

User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: Velocity » Sun Sep 16, 2007 3:11 pm

Here are a few tips (some will apply, others won't, I am just listing things that I can think of)

1) Sand the actual piston in order to allow the tape to get a slightly better grip on the piston.
2) Wrap the tape EXTREMELY tightly so it won't fall off.
3) Make sure the piston with the tape is the right thickness; too much, and there will be too much friction and it will get ripped off, along with poor performance; too little, and the air will rush by and the extra space that the piston has to move might also help to rip the tape off.
4) White lithium grease works great for me when I make pistons with duct tape.
5) Make sure your piston seat is smooth.
  • 0

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

Unread postAuthor: jackssmirkingrevenge » Sun Sep 16, 2007 4:49 pm

edit: enough with the lewd KY jokes, this is getting out of hand hehe
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: noob of noobs » Sun Oct 07, 2007 11:45 am

Okay, I'm terribly sorry for kicking up an old thread, but I haven't been able to do anything with cannons for a long time due to school.
I tried doing the aluminum can thing, and I still have the problem. Using my mouth, I can blow air into the piston valve through the ball valve pilot, and the piston seals fine. I can also suck air through it, and the piston moves back and forth. But when I charge the valve to 60 psi (much stronger than my mouth) and release the air, nothing happens. I lubed it up with petrolium grease, and it should work fine, but doesn't.
Any help?
  • 0

User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

Unread postAuthor: mopherman » Sun Oct 07, 2007 11:46 am

noob of noobs wrote:Okay, I'm terribly sorry for kicking up an old thread, but I haven't been able to do anything with cannons for a long time due to school.
I tried doing the aluminum can thing, and I still have the problem. Using my mouth, I can blow air into the piston valve through the ball valve pilot, and the piston seals fine. I can also suck air through it, and the piston moves back and forth. But when I charge the valve to 60 psi (much stronger than my mouth) and release the air, nothing happens. I lubed it up with petrolium grease, and it should work fine, but doesn't.
Any help?

what are using to pilot? try a 1/4 ball valve if you havnt already
  • 0

searching for a modern day savior from another place,inclined toward charity,everyone's begging for an answer,without regard to validity,the searching never ends,it goes on and on for eternity
-Bad religion
User avatar
mopherman
Brigadier General
Brigadier General
 
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Reputation: 0

Unread postAuthor: noob of noobs » Sun Oct 07, 2007 12:28 pm

I was using a 1/4" blowgun, but now I'm using a 1/2" ball valve.
  • 0

User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

Unread postAuthor: jrrdw » Sun Oct 07, 2007 1:23 pm

Can you get a pic up of the entire valve and pilot set up?
  • 0

When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6538
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: noob of noobs » Sun Oct 07, 2007 4:28 pm

Sure, but it'll be a while. The digital camera's in Wisconsin with my dad right now, but he'll be back tonight.
  • 0

User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

Unread postAuthor: noob of noobs » Sun Oct 07, 2007 5:50 pm

Ah, here we go.
Here's the setup of the valve: http://img264.imageshack.us/my.php?image=img2419kn4.jpg

And here's the piston: http://img172.imageshack.us/my.php?image=img2421dl3.jpg
Thank's for your help.
  • 0

User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

PreviousNext

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'