Go to Post you know you have overdosed to first when while you are reading all of these things, you can smile and say "oh yeah, i miss doing that" and then, you start to tear up and scream "I MISS FIRST!!!" - amanda547 [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 14-01-2014, 23:30
jaykris284 jaykris284 is offline
Registered User
FRC #1261
 
Join Date: Jan 2014
Location: Suwanee,GA
Posts: 24
jaykris284 is an unknown quantity at this point
Maintaining Ball Size at Competition

Hello,

After discussing for a bit and checking around with different teams team 1261 found that the ball diameters varied greatly from the two feet (or 24 inches). Some teams had balls as low as 20 inches and some as high as 28 inches.

Our question is, how is FIRST going to maintain a consistent ball size throughout the regionals?

It seems like a good idea would be to have a sizing cylinder at the events to ensure balls are at 24 inches.

Additionally couldn't balls be pumped with nitrogen to ensure that their diameter stays about the same throughout the events?
Reply With Quote
  #2   Spotlight this post!  
Unread 14-01-2014, 23:35
MrForbes's Avatar
MrForbes MrForbes is offline
Registered User
AKA: Jim
FRC #1726 (N.E.R.D.S.)
Team Role: Mentor
 
Join Date: Feb 2006
Rookie Year: 2006
Location: Sierra Vista AZ
Posts: 5,952
MrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond repute
Re: Maintaining Ball Size at Competition

Quote:
Originally Posted by jaykris284 View Post
Additionally couldn't balls be pumped with nitrogen to ensure that their diameter stays about the same throughout the events?
isn't that what air is? mostly

A better plan might be to make sure your robot will work with balls from 20 to 28 inches diameter....( perhaps less range, to allow for how different teams measure)
Reply With Quote
  #3   Spotlight this post!  
Unread 14-01-2014, 23:35
MrRoboSteve MrRoboSteve is offline
Mentor
AKA: Steve Peterson
FRC #3081 (Kennedy RoboEagles)
Team Role: Mentor
 
Join Date: Mar 2012
Rookie Year: 2011
Location: Bloomington, MN
Posts: 572
MrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond reputeMrRoboSteve has a reputation beyond repute
Re: Maintaining Ball Size at Competition

Note the precision of this statement from the rules:

Quote:
The BALLS are approximately 2 ft. diameter exercise BALLs
Our team is assuming that the size of the balls will vary.
__________________
2016-17 events: 10000 Lakes Regional, Northern Lights Regional, FTC Burnsville Qualifying Tournament

2011 - present · FRC 3081 Kennedy RoboEagles mentor
2013 - present · event volunteer at 10000 Lakes Regional, Northern Lights Regional, North Star Regional, Lake Superior Regional, Minnesota State Tournament, PNW District 4 Glacier Peak, MN FTC, CMP
http://twitter.com/MrRoboSteve · www.linkedin.com/in/speterson
Reply With Quote
  #4   Spotlight this post!  
Unread 14-01-2014, 23:42
Andy A. Andy A. is offline
Getting old
FRC #0095
Team Role: Coach
 
Join Date: Jun 2001
Rookie Year: 2001
Location: New Hampshire
Posts: 1,013
Andy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond reputeAndy A. has a reputation beyond repute
Re: Maintaining Ball Size at Competition

The manufacture describes them as 25", not 24" (or two feet).

The cover is really what should be controlling the diameter. Carefully look at the seams and how the zipper functions to verify that you've got it inflated to the same approximate size as FIRST is expecting them to be.

The big point, though, is to expect variation and design your mechanisms to tolerate that.
Reply With Quote
  #5   Spotlight this post!  
Unread 15-01-2014, 00:02
Jon Stratis's Avatar
Jon Stratis Jon Stratis is online now
Electrical/Programming Mentor
FRC #2177 (The Robettes)
Team Role: Mentor
 
Join Date: Feb 2007
Rookie Year: 2006
Location: Minnesota
Posts: 3,736
Jon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond reputeJon Stratis has a reputation beyond repute
Re: Maintaining Ball Size at Competition

If I remember right, one of the videos FIRST had on after kickoff talked about how to properly inflate the ball within the cover to ensure you were at the proper diameter. If FIRST went to the trouble of making a video with a specific process and acceptance criteria, I think we can trust them to do what the video says to give us as consistent a ball size as possible.
__________________
2007 - Present: Mentor, 2177 The Robettes
LRI: North Star 2012-2016; Lake Superior 2013-2014; MN State Tournament 2013-2014, 2016; Galileo 2016; Iowa 2017
2015: North Star Regional Volunteer of the Year
2016: Lake Superior WFFA
Reply With Quote
  #6   Spotlight this post!  
Unread 15-01-2014, 01:42
MrForbes's Avatar
MrForbes MrForbes is offline
Registered User
AKA: Jim
FRC #1726 (N.E.R.D.S.)
Team Role: Mentor
 
Join Date: Feb 2006
Rookie Year: 2006
Location: Sierra Vista AZ
Posts: 5,952
MrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond repute
Re: Maintaining Ball Size at Competition

Quote:
Originally Posted by Jon Stratis View Post
If FIRST went to the trouble of making a video with a specific process and acceptance criteria, I think we can trust them to do what the video says to give us as consistent a ball size as possible.
If history is any indication of the future....I kinda doubt it.
Reply With Quote
  #7   Spotlight this post!  
Unread 15-01-2014, 02:19
brandon.cottrell's Avatar
brandon.cottrell brandon.cottrell is offline
Vice President
FRC #1266 (The Devil Duckies)
Team Role: Leadership
 
Join Date: Nov 2013
Rookie Year: 2013
Location: San Diego
Posts: 235
brandon.cottrell has much to be proud ofbrandon.cottrell has much to be proud ofbrandon.cottrell has much to be proud ofbrandon.cottrell has much to be proud ofbrandon.cottrell has much to be proud ofbrandon.cottrell has much to be proud ofbrandon.cottrell has much to be proud ofbrandon.cottrell has much to be proud ofbrandon.cottrell has much to be proud of
Re: Maintaining Ball Size at Competition

While I'm glad that you're accounting that in the real world millimeters matter, I really don't think it will mess up your autonomous or tele-op that much. If a ball is visually different than what it's supposed to be, I'm sure the volunteers will regulate it.
Reply With Quote
  #8   Spotlight this post!  
Unread 15-01-2014, 09:13
Charles Boehm's Avatar
Charles Boehm Charles Boehm is offline
Build Team Lead, Weapons Officer
AKA: Charles
FRC #2175 (The Fighting Calculators)
Team Role: Leadership
 
Join Date: May 2013
Rookie Year: 2013
Location: Minnesota
Posts: 56
Charles Boehm is a jewel in the roughCharles Boehm is a jewel in the roughCharles Boehm is a jewel in the rough
Re: Maintaining Ball Size at Competition

Teams will have to be able to adjust to this. Its just like last year when frisbees became warped throughout competition. I know at least for our autonomous last year we had to choose very carefully which frisbees we pre-loaded because if they were warded they wouldn't always engage our limit switch.
Teams robots will have to be able to launch and pick up balls with varying diameters. Also the rule says the balls are roughly 2 ft in diameter. Not exactly.
Reply With Quote
  #9   Spotlight this post!  
Unread 15-01-2014, 09:58
Taylor's Avatar
Taylor Taylor is online now
Professor of Thinkology, ThD
AKA: @taylorstem
FRC #3487 (EarthQuakers)
Team Role: Teacher
 
Join Date: Jan 2006
Rookie Year: 2006
Location: Indianapolis, IN, USA 46227
Posts: 4,579
Taylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond reputeTaylor has a reputation beyond repute
Re: Maintaining Ball Size at Competition

Quote:
Originally Posted by Jon Stratis View Post
If I remember right, one of the videos FIRST had on after kickoff talked about how to properly inflate the ball within the cover to ensure you were at the proper diameter. If FIRST went to the trouble of making a video with a specific process and acceptance criteria, I think we can trust them to do what the video says to give us as consistent a ball size as possible.
Yes, Derek and Matt were able to get it to specifications easily and effectively. I wouldn't count on the teenager hanging out at a regional/district whose (one of many) job is to inflate the balls to have such a keen eye for detail.

Quote:
Originally Posted by Brandon1266 View Post
While I'm glad that you're accounting that in the real world millimeters matter, I really don't think it will mess up your autonomous or tele-op that much. If a ball is visually different than what it's supposed to be, I'm sure the volunteers will regulate it.
Depends on your manipulator. If the loader/ejector is relient on the ball having a specific size/surface consistency, the results on Saturday afternoon may be much different than those on Friday morning of competition.
__________________
Hi!
Reply With Quote
  #10   Spotlight this post!  
Unread 15-01-2014, 10:28
MechEng83's Avatar
MechEng83 MechEng83 is offline
Lead Mentor/Engineer
AKA: Mr. Cool
FRC #1741 (Red Alert)
Team Role: Coach
 
Join Date: May 2011
Rookie Year: 2011
Location: Indiana
Posts: 616
MechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond reputeMechEng83 has a reputation beyond repute
Re: Maintaining Ball Size at Competition

Quote:
Originally Posted by Taylor View Post
Depends on your manipulator. If the loader/ejector is relient on the ball having a specific size/surface consistency, the results on Saturday afternoon may be much different than those on Friday morning of competition.
Hence the reason having a ball launcher that is insensitive to inflation was weighted high on our design matrix.
__________________

2016 INWLA GP| INWCH Entrepreneurship | INPMH DCA | INCMP Team Spirit | CAGE Match Winner (w/ 1747 &868), Finalist (1471 w/ 1529 & 1018), Best Fans
2015 ININD Judges Award, Proud "Phyxed Red Card" alliance partners of 1529 & 1720 | INWLA EI | INCMP GP
2014 Boilermaker Creativity | Chesapeake Finalist, Safety, GP, Entrepreneurship | IN State Championship Winner (w/ 868 & 1018) | CAGE Match Winner (w/ 1024, 5402 & 1646)
2013 Boilermaker RCA, Innovation in Controls, Finalist | Crossroads Entrepreneurship | Newton Semi-finalist
2012 Boilermaker Entrepreneurship | Queen City EI | Curie Semi-finalist
2011 Boilermaker RCA, Entrepreneurship
Red Alert Robotics
Reply With Quote
  #11   Spotlight this post!  
Unread 15-01-2014, 10:50
Jared Russell's Avatar
Jared Russell Jared Russell is offline
Taking a year (mostly) off
FRC #0254 (The Cheesy Poofs), FRC #0341 (Miss Daisy)
Team Role: Engineer
 
Join Date: Nov 2002
Rookie Year: 2001
Location: San Francisco, CA
Posts: 3,073
Jared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond reputeJared Russell has a reputation beyond repute
Re: Maintaining Ball Size at Competition

20 to 28 inches does not sound plausible to me. All of the balls that I have seen have been in the 24 to 26 range. I might even buy 23 or 27. Are you sure all of the balls you handled were official FIRST game pieces and not COTS yoga balls or replacement bladders?
Reply With Quote
  #12   Spotlight this post!  
Unread 15-01-2014, 10:57
MrForbes's Avatar
MrForbes MrForbes is offline
Registered User
AKA: Jim
FRC #1726 (N.E.R.D.S.)
Team Role: Mentor
 
Join Date: Feb 2006
Rookie Year: 2006
Location: Sierra Vista AZ
Posts: 5,952
MrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond repute
Re: Maintaining Ball Size at Competition

Quote:
Originally Posted by MrForbes View Post
( perhaps less range, to allow for how different teams measure)
I tried to cover that...I guess I was too subtle
Reply With Quote
  #13   Spotlight this post!  
Unread 15-01-2014, 11:08
Bryan Herbst's Avatar
Bryan Herbst Bryan Herbst is offline
Registered User
AKA: Bryan
FRC #2052 (KnightKrawler)
Team Role: Mentor
 
Join Date: Sep 2007
Rookie Year: 2007
Location: Minneapolis, Minnesota
Posts: 544
Bryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond reputeBryan Herbst has a reputation beyond repute
Re: Maintaining Ball Size at Competition

Quote:
Originally Posted by Taylor View Post
Yes, Derek and Matt were able to get it to specifications easily and effectively. I wouldn't count on the teenager hanging out at a regional/district whose (one of many) job is to inflate the balls to have such a keen eye for detail.
Because there will be so few balls out on the field, the Field Supervisor can (and should) monitor this adequately.

2011 was a bit more difficult to monitor due to the number of inner tubes available, but I don't recall this being a problem that year.

If a team sees a ball that is significantly off from the specified "approximately 2 feet," they should ask to speak to the field supervisor. The field supervisor should be more than happy to correct the problem.
__________________
Team 2052- Knightkrawler
Mentor and volunteer
Reply With Quote
  #14   Spotlight this post!  
Unread 15-01-2014, 11:13
PayneTrain's Avatar
PayneTrain PayneTrain is offline
Trickle-Down CMP Allocation
AKA: Lizard King
FRC #0422 (The Meme Tech Pneumatic Devices)
Team Role: Mascot
 
Join Date: Mar 2010
Rookie Year: 2009
Location: RVA
Posts: 2,237
PayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond reputePayneTrain has a reputation beyond repute
Re: Maintaining Ball Size at Competition

I haven't bothered to investigate the ball with.without the cover, but I imagine the cover will do the job of keeping the ball within 2-3 inches of the recorded diameter and within 1oz of estimated weight. However, one little thing teams overlook every year is dealing with changing conditions of gamepieces throughout the event. Don't rely on the field staff to get every ball to work with your machine (they have more important things to do), engineer a robot that makes the change not matter.
Reply With Quote
  #15   Spotlight this post!  
Unread 15-01-2014, 11:14
Drivencrazy's Avatar
Drivencrazy Drivencrazy is offline
Mentor
AKA: Clint Ott
FRC #1011
Team Role: Mentor
 
Join Date: Mar 2009
Rookie Year: 2009
Location: Lee's Summit, Mo.
Posts: 177
Drivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant futureDrivencrazy has a brilliant future
Re: Maintaining Ball Size at Competition

Quote:
Originally Posted by Tanis View Post
2011 was a bit more difficult to monitor due to the number of inner tubes available, but I don't recall this being a problem that year.
I seem to recall this being quite a bit of a problem in 2011 because of the different shaped tubes. I think in 2011 they had a "device" (2 pieces of plywood a set distance apart) that checked for tube over inflation but don't quote me on that.

I don't think the inflation will vary much beyond 24-26 inches but it's definitely something to account for.
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 14:14.

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