Go to Post No, nothing secret unless you include the following: will it work?, can it be driven and will it release the balls. - twolf [more]
Home
Go Back   Chief Delphi > Technical > Pneumatics
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
 
Thread Tools Rating: Thread Rating: 3 votes, 3.67 average. Display Modes
  #1   Spotlight this post!  
Unread 30-09-2006, 16:41
Kevin Sevcik's Avatar
Kevin Sevcik Kevin Sevcik is offline
(Insert witty comment here)
FRC #0057 (The Leopards)
Team Role: Mentor
 
Join Date: Jun 2001
Rookie Year: 1998
Location: Houston, Texas
Posts: 3,701
Kevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond reputeKevin Sevcik has a reputation beyond repute
Send a message via AIM to Kevin Sevcik Send a message via Yahoo to Kevin Sevcik
Re: Optimizing Air Cannon Range

Your cannon is honking when you fire it? If so, I suspect your fancy rainbird valve isn't working as well as you think. I'm actually surprised it's even sealing particulary well, since the one I used for my ping-pong ball cannon refused to seal with air without heavy modifications.

At any rate, you probably need to make the whole air system more efficient. 10' of 1" tubing is going to restrict a lot of your air flow. Chances are that your t-shirt will be mostly down your barrel before any of the air from te storage tank gets to the valve. Secondly, your valve needs to open rapidly and completely. Right now, it sounds like it's mostly opening, and the are rusing past the membrane inside is making it vibrate and disrupt the airflow. You can either switch to a butterfly valve actuated with a pneumatic piston, or modify your solenoid valve. I sealed up the hole in the membrane, and pressurized the top chamber seperately. I also put a spring inside the valve to push the membrane up and out of the way more completely.

That's all assuming you want to improve your design. Your other option is to simply throw more PSI at everything, and hope nothing explodes and injures you. Seriously. Your tubing and valve there are only meant to work with water, which is fairly incompressible. Filling up that 1" tube with compressed air is an accident waiting to happen. Especially since it sounds like the only pressure control in your system is the 120 psi relief valve on the compressor.

At any rate, efficiency is more fun. My ping-pong cannon was about 1' long, total. The air chamber was 4" of 1.5" PVC, and the barrel was about 3" long. It still launched balls farther than the huge monstrosities other teams built with 2 foot long barrels and 2'x3" air chambers. Unfortunately, the goal was accuracy, and that's a bit hard with a cannon that shoots things 30' on 20 psi.
__________________
The difficult we do today; the impossible we do tomorrow. Miracles by appointment only.

Lone Star Regional Troubleshooter
  #2   Spotlight this post!  
Unread 30-09-2006, 16:54
Andrew Blair's Avatar
Andrew Blair Andrew Blair is offline
SAE Formula is FIRST with Gasoline.
FRC #0306 (CRT)
Team Role: Alumni
 
Join Date: Feb 2005
Rookie Year: 2004
Location: Corry
Posts: 1,193
Andrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond repute
Send a message via AIM to Andrew Blair Send a message via Yahoo to Andrew Blair
Re: Optimizing Air Cannon Range

Three things: like Cody said, rolling the t-shirt and taping it will significantly improve your range. Secondly, the valve has an ID of like 3/4", so your tank with the 1/2" fitting may be a bottleneck, but thirdly, t-shirts are not really the best projectiles for perfomance. If you really want to see capability, find a ball that more or less perfectly fit's the ID of your barrel. Shirts, unless rolled in a very tight, almost bullet like shape with a perfect mate to your barrel, will not fly extremely well, no matter what you do.
__________________
Reading makes a full man, conference a ready man, and writing an exact man.
-Sir Francis Bacon

"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."
-Albert Einstein
Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
potato cannon northendchopper Chit-Chat 14 16-12-2009 12:19
pic: Toltech Air Cannon Prototype Andrew Schuetze Extra Discussion 2 29-05-2007 15:29
FIRST air cannon robots PVC?? Andrew Schuetze Pneumatics 40 03-01-2007 15:16
Air Cannon Michael223 Technical Discussion 13 14-06-2006 10:23
Are we allowed to use a Bimba air-to-air booster? Alex Minot Pneumatics 1 20-02-2005 22:32


All times are GMT -5. The time now is 06:23.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi