Go to Post This is why I love this game. It's like high speed chess with flashing lights and lots of noise. - Karthik [more]
Home
Go Back   Chief Delphi > FIRST > General Forum
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Reply
 
Thread Tools Rating: Thread Rating: 2 votes, 5.00 average. Display Modes
  #1   Spotlight this post!  
Unread 05-01-2014, 18:55
Richard Wallace's Avatar
Richard Wallace Richard Wallace is offline
I live for the details.
FRC #3620 (Average Joes)
Team Role: Engineer
 
Join Date: Jan 2003
Rookie Year: 1996
Location: Southwestern Michigan
Posts: 3,646
Richard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond reputeRichard Wallace has a reputation beyond repute
Re: Using an air cannon to launch the balls - Arial Assist

Your cannon barrel bore diameter would need to be about two feet to accept the ball -- that is about 450 square inch cross-section area. Robot rule <R82> limits working air pressure to 60 pounds per square inch. The ball weighs about 2.75 pounds.

The numbers do not appear favorable for launch.
__________________
Richard Wallace

Mentor since 2011 for FRC 3620 Average Joes (St. Joseph, Michigan)
Mentor 2002-10 for FRC 931 Perpetual Chaos (St. Louis, Missouri)
since 2003

I believe in intuition and inspiration. Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution. It is, strictly speaking, a real factor in scientific research.
(Cosmic Religion : With Other Opinions and Aphorisms (1931) by Albert Einstein, p. 97)
Reply With Quote
  #2   Spotlight this post!  
Unread 05-01-2014, 19:54
yash101 yash101 is offline
Curiosity | I have too much of it!
AKA: null
no team
 
Join Date: Oct 2012
Rookie Year: 2012
Location: devnull
Posts: 1,191
yash101 is an unknown quantity at this point
Re: Using an air cannon to launch the balls - Arial Assist

Quote:
Originally Posted by Richard Wallace View Post
Your cannon barrel bore diameter would need to be about two feet to accept the ball -- that is about 450 square inch cross-section area. Robot rule <R82> limits working air pressure to 60 pounds per square inch. The ball weighs about 2.75 pounds.

The numbers do not appear favorable for launch.
450*60 = 27000 lbf! I think that is quite some power, unless that is the wrong formula!

27,000 lbf would probably be enough to move a big-rig! I wonder what would happen to the ball!

Just remember: The compressor is a decent-sized motor in charge of storing a ton of energy as compressed gas. Over time, this power builds up until you have stored, for example, 100 watts of energy which you release it within a second! I think that would be:
100w*60s*60m = 360,000 watts per hour are delivered!

THAT IS DANGEROUS!
Reply With Quote
  #3   Spotlight this post!  
Unread 05-01-2014, 21:17
PAR_WIG1350's Avatar
PAR_WIG1350 PAR_WIG1350 is offline
Registered User
AKA: Alan Wells
FRC #1350 (Rambots)
Team Role: Alumni
 
Join Date: Dec 2009
Rookie Year: 2009
Location: Rhode Island
Posts: 1,189
PAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond reputePAR_WIG1350 has a reputation beyond repute
Re: Using an air cannon to launch the balls - Arial Assist

Quote:
Originally Posted by yash101 View Post
Just remember: The compressor is a decent-sized motor in charge of storing a ton of energy as compressed gas. Over time, this power builds up until you have stored, for example, 100 watts of energy which you release it within a second! I think that would be:
100w*60s*60m = 360,000 watts per hour are delivered!

THAT IS DANGEROUS!
I don't mean to pick on you, but I will take this opportunity to explain the importance of understanding your units.

You are correct in saying that the compressor stores energy in the form of compressed gas, but it isn't stored as power.

Power is a measurement of energy transferred per unit of time. One Watt is equal to one Joule of energy per second. As the compressor operates, it converts electrical potential energy into mechanical energy (by compressing air) and heat. If It does this at 12 volts and 15 Amps, It would be running at 12*15, or 180 watts. If it runs for 1 hour, It converts 180 Watt-hours of energy, or 180 * 3600 Joules.

Not all of that is stored, however, since a lot of it is lost as heat while the motor is running. Still, even a fraction 648kJ could be quite lethal if it is released carelessly.
__________________
Reply With Quote
  #4   Spotlight this post!  
Unread 05-01-2014, 22:19
yash101 yash101 is offline
Curiosity | I have too much of it!
AKA: null
no team
 
Join Date: Oct 2012
Rookie Year: 2012
Location: devnull
Posts: 1,191
yash101 is an unknown quantity at this point
Re: Using an air cannon to launch the balls - Arial Assist

Quote:
Originally Posted by PAR_WIG1350 View Post
I don't mean to pick on you, but I will take this opportunity to explain the importance of understanding your units.

You are correct in saying that the compressor stores energy in the form of compressed gas, but it isn't stored as power.

Power is a measurement of energy transferred per unit of time. One Watt is equal to one Joule of energy per second. As the compressor operates, it converts electrical potential energy into mechanical energy (by compressing air) and heat. If It does this at 12 volts and 15 Amps, It would be running at 12*15, or 180 watts. If it runs for 1 hour, It converts 180 Watt-hours of energy, or 180 * 3600 Joules.

Not all of that is stored, however, since a lot of it is lost as heat while the motor is running. Still, even a fraction 648kJ could be quite lethal if it is released carelessly.
I know that. However, I am contrasting to a unit that most people would know about!

and just for the sake of lols, I have Copioli opened in another tab and someone's singing the Friday Song
Reply With Quote
  #5   Spotlight this post!  
Unread 06-01-2014, 08:19
wireties's Avatar
wireties wireties is offline
Principal Engineer
AKA: Keith Buchanan
FRC #1296 (Full Metal Jackets)
Team Role: Mentor
 
Join Date: Jan 2006
Rookie Year: 2004
Location: Rockwall, TX
Posts: 1,170
wireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond repute
Send a message via AIM to wireties
Re: Using an air cannon to launch the balls - Arial Assist

The nylon bag around the ball will make sealing against your air cannon aperture quite difficult. Personally I would not try it.
__________________
Fast, cheap or working - pick any two!
Reply With Quote
  #6   Spotlight this post!  
Unread 06-01-2014, 10:45
RRLedford RRLedford is offline
FTC 3507 Robo Theosis -- FRC 3135
AKA: Dick Ledford
FRC #3135 (Robotic Colonels)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2009
Location: Chicago, IL USA
Posts: 286
RRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond reputeRRLedford has a reputation beyond repute
Re: Using an air cannon to launch the balls - Arial Assist

Quote:
Originally Posted by wireties View Post
The nylon bag around the ball will make sealing against your air cannon aperture quite difficult. Personally I would not try it.
Do you mean that if ball is a tight not a enough fit in the canon bore, then when you apply air pressure to launch it, the ball will not be deformed enough to keep a good seal, or perhaps the pressure may deform ball too much and make it start to act like a brake?

-Dick Ledford
__________________
FTC 3507 RoboTheosis
FRC 3135 Robotic Colonels
Reply With Quote
  #7   Spotlight this post!  
Unread 06-01-2014, 12:31
wireties's Avatar
wireties wireties is offline
Principal Engineer
AKA: Keith Buchanan
FRC #1296 (Full Metal Jackets)
Team Role: Mentor
 
Join Date: Jan 2006
Rookie Year: 2004
Location: Rockwall, TX
Posts: 1,170
wireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond repute
Send a message via AIM to wireties
Re: Using an air cannon to launch the balls - Arial Assist

Quote:
Originally Posted by RRLedford View Post
Do you mean that if ball is a tight not a enough fit in the canon bore, then when you apply air pressure to launch it, the ball will not be deformed enough to keep a good seal, or perhaps the pressure may deform ball too much and make it start to act like a brake?

-Dick Ledford

one can imagine that if there were a fixed air gap around the ball it would be difficult to launch and that a zero air gap (a good seal) is ideal - so how does having that nylon bag compromise the seal, how much air escapes without doing any work?
__________________
Fast, cheap or working - pick any two!
Reply With Quote
Reply


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


All times are GMT -5. The time now is 15:22.

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