OCCRA
Go to Post Word of advice:Don't eat a whole box of nutrigrain bars that are loaded with fiber in one sitting...Yeah.. Bad thing. - Elgin Clock [more]
Home
Go Back   Chief Delphi > Technical > Pneumatics
CD-Events   CD-Media   CD-Spy   FRC-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 03-29-2012, 08:14 PM
JP Carlin's Avatar
JP Carlin JP Carlin is offline
Registered User
FRC #2487 (Mechanical Animals)
Team Role: Programmer
 
Join Date: Feb 2010
Rookie Year: 2008
Location: Sayville NY
Posts: 42
JP Carlin is on a distinguished road
Bridge reset

So tomorrow is our fist day of actual competition at the Long Island Regional and our original bridge reset plan did not work. We are now reorienting the pneumatics that were going to lower the bridge to get them to direct more force on to the bridge hoping that that would bet us able to push it down more successfully, My question is that I know very little about pneumatics and all I really need to know is where I can get the specifications on the pneumatics im using to do the math and find out if im getting enough force out of it.

Dont know if I made complete sense so ill just add the main points of what I need to find here:
-where can I look up the specifications of my pneumatics and find out how much force they are delivering?
-What is the minimum amount of force needed to lower the bridge?

-And if anyone has tested both of the following which one have you had more success with: An arm lowering the bridge, or a wedge coming down and then driving into the bridge
  #2   Spotlight this post!  
Unread 03-29-2012, 08:19 PM
kevin.li.rit's Avatar
kevin.li.rit kevin.li.rit is offline
Imaginary Friend
AKA: Kevin Li
FRC #0596 (SciClones)
Team Role: Student
 
Join Date: Jan 2003
Rookie Year: 2001
Location: Hopkinton, Massachusetts
Posts: 862
kevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant future
Send a message via Yahoo to kevin.li.rit
Re: Bridge reset

I'm told it is about 16 lbs.

The force your pneumatics delivers is dependent on the bore size.

The max working pressure on the robot is 60 PSI( Pounds per square inch). Calculate the area of the bore size to get the force.
__________________
Kevin Li

596 - Sciclones
1405 - Finney Falcons
2262 - Holliston Panthers
  #3   Spotlight this post!  
Unread 03-29-2012, 08:22 PM
JustinRueb1891's Avatar
JustinRueb1891 JustinRueb1891 is offline
FRC 1891 alumni 2012
AKA: Justin Rueb
FRC #1891 (Bullbots)
Team Role: College Student
 
Join Date: May 2011
Rookie Year: 2009
Location: Boise, ID
Posts: 34
JustinRueb1891 is a jewel in the roughJustinRueb1891 is a jewel in the roughJustinRueb1891 is a jewel in the roughJustinRueb1891 is a jewel in the rough
Re: Bridge reset

Quote:
Originally Posted by JP Carlin View Post

-And if anyone has tested both of the following which one have you had more success with: An arm lowering the bridge, or a wedge coming down and then driving into the bridge
We used a wedge, and it worked perfectly (until we bent the mechanical lock to keep it in place in elims ). IMO, the best way to manipulate the bridge is to lower a wedge and lock it into place, so the bridge won't fold your wedge right back into the robot. Good luck!
__________________
FRC Team 1891 - The Bullbots (2009-2012)
2012 Industrial Safety Award - Utah Regional
2011 Regional Chairman's Award - Utah Regional
2010 Gracious Professionalism Award - Utah Regional
2009 Gracious Professionalism Award - Portland Regional
  #4   Spotlight this post!  
Unread 03-29-2012, 08:41 PM
Peck's Avatar
Peck Peck is offline
worse then failing: proving murphy
FRC #1619 (Up-A-Creek Robotics) and FTC # 4633)
Team Role: College Student
 
Join Date: Mar 2012
Rookie Year: 2007
Location: Colorado
Posts: 237
Peck will become famous soon enough
Re: Bridge reset

What is best to manipulate the bridge depends on what you have. Making a wedge that would work well requires a lot of things like:
space for the mechanism (wedge is often bigger then a pusher)
To be reliable, you have to have 2 wedges applying even force to both sides
it has to be joined together at farthest extent at all times (per the rules)
you have to be able to lower the entire system efficiently
greater attention to detail (a wedge is usually an all or nothing and if you get something wrong, you have to re-engineer the whole thing while with something pushing it down, if you don't go far enough, you cut a bigger whole, attach something to the end, or make a brace)
And the wedge design usually has more fail points though this depends on how u build it.

now, if u built a big wedge as part of your frame, that is a different story but right now is likely a little late to implement that.
__________________
Cad, Electrical, Machining, Debugging (old school), PR, Distraction elimination


TEAM 1619
__UP-A-Creek Robotics__
It ain't done till it's over-done
  #5   Spotlight this post!  
Unread 03-29-2012, 08:50 PM
JP Carlin's Avatar
JP Carlin JP Carlin is offline
Registered User
FRC #2487 (Mechanical Animals)
Team Role: Programmer
 
Join Date: Feb 2010
Rookie Year: 2008
Location: Sayville NY
Posts: 42
JP Carlin is on a distinguished road
Re: Bridge reset

So i made the measurements and for what I intend on working with I have 2 pneumatics with a 1.5 inch bore and I believe an 10in stroke. I found a table giving the extending force of a pneumatic and my results are more then double what the table says so if someone could just double check my math and tell me if they have the same thing.
so force=area * psi
(3.14)(1.5in)*(60psi)=282.6lbs of force
table says that the force with this should be 106lbs

Here the link to the table I found
http://www.usfirst.org/sites/default... %20Manual.pdf

any idea on which force I should use
  #6   Spotlight this post!  
Unread 03-29-2012, 08:52 PM
kevin.li.rit's Avatar
kevin.li.rit kevin.li.rit is offline
Imaginary Friend
AKA: Kevin Li
FRC #0596 (SciClones)
Team Role: Student
 
Join Date: Jan 2003
Rookie Year: 2001
Location: Hopkinton, Massachusetts
Posts: 862
kevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant future
Send a message via Yahoo to kevin.li.rit
Re: Bridge reset

Quote:
Originally Posted by JP Carlin View Post
So i made the measurements and for what I intend on working with I have 2 pneumatics with a 1.5 inch bore and I believe an 10in stroke. I found a table giving the extending force of a pneumatic and my results are more then double what the table says so if someone could just double check my math and tell me if they have the same thing.
so force=area * psi
(3.14)(1.5in)*(60psi)=282.6lbs of force
table says that the force with this should be 106lbs

Here the link to the table I found
http://www.usfirst.org/sites/default... %20Manual.pdf

any idea on which force I should use
106

It is pi*.75inch^2 * 60 PSI = 106lbs

This is because a 1.5 inch bore has a radius of .75 inches.
__________________
Kevin Li

596 - Sciclones
1405 - Finney Falcons
2262 - Holliston Panthers

Last edited by kevin.li.rit : 03-29-2012 at 08:54 PM. Reason: units.
  #7   Spotlight this post!  
Unread 03-29-2012, 08:54 PM
Shaun Coon's Avatar
Shaun Coon Shaun Coon is offline
Registered User
FRC #2487
 
Join Date: Jan 2012
Location: New York
Posts: 45
Shaun Coon is a jewel in the roughShaun Coon is a jewel in the roughShaun Coon is a jewel in the roughShaun Coon is a jewel in the rough
Re: Bridge reset

your math is correct
  #8   Spotlight this post!  
Unread 03-29-2012, 08:54 PM
DonRotolo's Avatar
DonRotolo DonRotolo is offline
Feeling Honorable
FRC #1676 (Pascack PI Oneers)
Team Role: Mentor
 
Join Date: Jan 2005
Rookie Year: 2005
Location: Montvale NJ
Posts: 6,510
DonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond repute
Re: Bridge reset

PI R Squared is the area of a circle.
We know this because we are the PI-O-Neers...
__________________

I am N2IRZ - What's your callsign?
  #9   Spotlight this post!  
Unread 03-29-2012, 09:03 PM
JP Carlin's Avatar
JP Carlin JP Carlin is offline
Registered User
FRC #2487 (Mechanical Animals)
Team Role: Programmer
 
Join Date: Feb 2010
Rookie Year: 2008
Location: Sayville NY
Posts: 42
JP Carlin is on a distinguished road
Re: Bridge reset

Quote:
Originally Posted by DonRotolo View Post
PI R Squared is the area of a circle.
We know this because we are the PI-O-Neers...
I see what you did there thanks for the corrections cant believe i mixed up diameter and radius but o well
  #10   Spotlight this post!  
Unread 03-29-2012, 09:19 PM
JP Carlin's Avatar
JP Carlin JP Carlin is offline
Registered User
FRC #2487 (Mechanical Animals)
Team Role: Programmer
 
Join Date: Feb 2010
Rookie Year: 2008
Location: Sayville NY
Posts: 42
JP Carlin is on a distinguished road
Re: Bridge reset

One last question and then i should have this pretty much down.

Ive only used these equations using metrics before so if
Torque=Force * Distance * sin of angle

Am i using distance as inches or feet when calculating this
  #11   Spotlight this post!  
Unread 03-29-2012, 09:20 PM
kevin.li.rit's Avatar
kevin.li.rit kevin.li.rit is offline
Imaginary Friend
AKA: Kevin Li
FRC #0596 (SciClones)
Team Role: Student
 
Join Date: Jan 2003
Rookie Year: 2001
Location: Hopkinton, Massachusetts
Posts: 862
kevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant futurekevin.li.rit has a brilliant future
Send a message via Yahoo to kevin.li.rit
Re: Bridge reset

Quote:
Originally Posted by JP Carlin View Post
One last question and then i should have this pretty much down.

Ive only used these equations using metrics before so if
Torque=Force * Distance * sin of angle

Am i using distance as inches or feet when calculating this
Either one.

106lbs with a 1 ft lever arm would be 106Ft*lbs or 1272inch*lbs.
__________________
Kevin Li

596 - Sciclones
1405 - Finney Falcons
2262 - Holliston Panthers
  #12   Spotlight this post!  
Unread 03-29-2012, 11:05 PM
slijin's Avatar
slijin slijin is offline
Pockets
AKA: Samuel Lijin
FRC #0694 (StuyPulse)
Team Role: Mentor
 
Join Date: Jan 2010
Rookie Year: 2010
Location: New York City
Posts: 537
slijin is a splendid one to beholdslijin is a splendid one to beholdslijin is a splendid one to beholdslijin is a splendid one to beholdslijin is a splendid one to beholdslijin is a splendid one to beholdslijin is a splendid one to behold
Re: Bridge reset

Quote:
Originally Posted by Coffeeism View Post
I'm told it is about 16 lbs.
Keep in mind that this is the vertical force required; if you're driving into the bridge with a wedge, that means the vertical component of the force has to be ~16+ lbf.
__________________

2010-12 CT Chairman's
2011 Galileo 5th seed
2010 NY Regional Winners
  #13   Spotlight this post!  
Unread 03-30-2012, 07:14 PM
JP Carlin's Avatar
JP Carlin JP Carlin is offline
Registered User
FRC #2487 (Mechanical Animals)
Team Role: Programmer
 
Join Date: Feb 2010
Rookie Year: 2008
Location: Sayville NY
Posts: 42
JP Carlin is on a distinguished road
Re: Bridge reset

Thanks for the help guys i was up manufacturing that part in the small shop I had in my garage all night and it worked out great. Doing very well so far in the competition
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


All times are GMT -5. The time now is 09:45 PM.

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


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi