Go to Post Losing is important. In some cases, more so than winning. - JackS [more]
Home
Go Back   Chief Delphi > FIRST > Robot Showcase
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #136   Spotlight this post!  
Unread 26-11-2012, 14:08
Madison's Avatar
Madison Madison is offline
Dancing through life...
FRC #0488 (Xbot)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1999
Location: Seattle, WA
Posts: 5,244
Madison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

These threads are interesting -- and we don't see many of them around anymore, unfortunately -- because they document someone's effort to make a better mousetrap. What becomes clear as the discussion progresses is that there are still lots of folks that still have a lot to learn about the forces at work and considerations we face while making decisions about how a mechanism will work. I might've appreciated this a bit more if there were not 6+ pages of attention-seeking.

As shown, this almost absolutely will not work. It appears to offer no advantage over swerve drive but has several disadvantages that swerve does not suffer. I'd like to see some math justifying ANY of the claims y'all have made re: friction, pneumatic cylinder size, etc.
__________________
--Madison--

...down at the Ozdust!

Like a grand and miraculous spaceship, our planet has sailed through the universe of time. And for a brief moment, we have been among its many passengers.
  #137   Spotlight this post!  
Unread 26-11-2012, 14:41
Ryan Dognaux's Avatar
Ryan Dognaux Ryan Dognaux is offline
Back Home in Indiana
FRC #4329 (Lutheran Roboteers)
Team Role: Mentor
 
Join Date: Apr 2002
Rookie Year: 2001
Location: Indianapolis, IN
Posts: 2,675
Ryan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond repute
Send a message via AIM to Ryan Dognaux
Re: Be afraid... Be VERY Afraid

Quote:
Originally Posted by bhumudar View Post
Lets suppose you see an incoming robot front the right of our robot, we would turn the wheels so that they face front to back (perpendicular to the incoming force).
Maybe I'm not thinking clearly, but why would you ever want to do this with the drive module you're intending to build? If anything with this drive you would want to avoid robot to robot contact if at all possible. I just see this probably losing any pushing matches with a standard 4 CIM 6WD setup, but would love to be proven wrong.
__________________
Ryan Dognaux :: Last Name Pronounced 'Doane Yo'
Team 234 Alum: 2002 - 2005 :: Purdue FIRST Member: 2006 - 2009
Team 1646 Mentor: 2007 - 2009 :: Team 357 Mentor: 2009 - 2012
Team 4329 Mentor: Current
STL Off-Season Event: www.gatewayroboticschallenge.com
  #138   Spotlight this post!  
Unread 26-11-2012, 14:41
sanddrag sanddrag is offline
On to my 16th year in FRC
FRC #0696 (Circuit Breakers)
Team Role: Teacher
 
Join Date: Jul 2002
Rookie Year: 2002
Location: Glendale, CA
Posts: 8,519
sanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond reputesanddrag has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

I'm curious what particular product or material he intends to use for the ball.

You might be interested in this: http://www.autoblog.com/2012/09/19/s...eering-studen/
__________________
Teacher/Engineer/Machinist - Team 696 Circuit Breakers, 2011 - Present
Mentor/Engineer/Machinist, Team 968 RAWC, 2007-2010
Technical Mentor, Team 696 Circuit Breakers, 2005-2007
Student Mechanical Leader and Driver, Team 696 Circuit Breakers, 2002-2004
  #139   Spotlight this post!  
Unread 26-11-2012, 22:05
BJC's Avatar
BJC BJC is offline
Simplicity is Complicated!
AKA: Bryan Culver
FRC #0033 (The Killer Bees)
Team Role: Alumni
 
Join Date: Jan 2010
Rookie Year: 2009
Location: Kettering/Greenville
Posts: 708
BJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond reputeBJC has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

Hey there,

I see that this idea/module was pretty much completely picked apart and shown to be a horrible idea so I won't bother with telling you any of that. Hopefully, you’re not too disappointed that the module/idea that you probably spent a long time designing isn't as great as you thought it was.

I just wanted to take a second to encourage you to continue thinking, inventing, and innovating. The people on this forum just want your team to be successful. Posting your designs on the forum is a gutsy move as any new design will be dismembered by many smart people. It is also one of the best things you can do as you get free constructive criticism from a bunch of smart people that have collective experience beyond what you could ever hope to gather by yourself.

Anyways, I hope you can take this away as a positive experience. If you hadn't posted on here and instead just went ahead and built your drivetrain for the 2013 season you would almost certainly be fighting your design the entire season and had a not-fun-at-all experience as a result.

Good Luck in your 2013 season and your future design endeavors.

Kind Regards, Bryan
__________________
robot robot robot? Robot. Robot? Robot!
-----------------Team 33------------------
  #140   Spotlight this post!  
Unread 26-11-2012, 22:31
BrendanB BrendanB is offline
Registered User
AKA: Brendan Browne
FRC #1058 (PVC Pirates)
Team Role: Mentor
 
Join Date: Feb 2008
Rookie Year: 2003
Location: Londonderry, NH
Posts: 3,104
BrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond reputeBrendanB has a reputation beyond repute
Thumbs up Re: Be afraid... Be VERY Afraid

Wow I was not expecting to see that when I logged in today!

I do agree that this drive isn't the best choice for FRC application unless the game changed to limit robot to robot contact and it wasn't so complex. Every drive has its weaknesses.

I do want to congratulate you for thinking outside the box. Too many of us get caught up in trying to keep up with the elite teams by making swerves, WCDs, octocanums, etc without really trying to come up with the something new or reinvent the wheel er... ball! Great model and design! Keep it up!

I would encourage to keep working on this model. Maybe you could build one as an off-season/fun build project! You could even rework your wheel choice and have a sweet module for octocanum by switching one wheel for a mecanum!

To everyone else. Is the design far fetched? Maybe. Are there some problems in the design? Possibly. But let's keep this as a positive discussion. Someone put a lot of time and effort into designing and modeling something cool and by keeping positive discussions going we encourage more designs to come forth instead of lurking on members' desktops in fear that we will tear it apart in our posts. Every year I dream of 8wd WCD swerves!

Nice work and good luck in your future designs!
Brendan
__________________
1519 Mechanical M.A.Y.H.E.M. 2008 - 2010
3467 Windham Windup 2011 - 2015
1058 PVC Pirates 2016 - xxxx

Last edited by BrendanB : 27-11-2012 at 00:56.
  #141   Spotlight this post!  
Unread 26-11-2012, 22:52
EricH's Avatar
EricH EricH is offline
New year, new team
FRC #1197 (Torbots)
Team Role: Engineer
 
Join Date: Jan 2005
Rookie Year: 2003
Location: SoCal
Posts: 19,825
EricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

I would say that if the module were used in FRC competition, you'd probably run into some difficulties in steering and traction, as noted already. (Aside from the potential for terrain popping the ball out if there wasn't a retaining device--I didn't see one in the model.)

But... I would suggest building one as an offseason project if you don't do it in season. Build a T-shirt cannon (or other promo device) on top of it. Offseason demobots need a "COOL!" factor, which I think this has--especially if it works as advertised.
__________________
Past teams:
2003-2007: FRC0330 BeachBots
2008: FRC1135 Shmoebotics
2012: FRC4046 Schroedinger's Dragons

"Rockets are tricky..."--Elon Musk

  #142   Spotlight this post!  
Unread 26-11-2012, 23:51
Garret's Avatar
Garret Garret is offline
Standing on the Shoulders of Giants
AKA: Garret Smalley
FRC #0691 (Hart District Robotics)
Team Role: Mentor
 
Join Date: Dec 2009
Rookie Year: 2008
Location: Goleta, CA (UCSB)
Posts: 203
Garret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

I spend my free time making crazy designs like this in CAD, as such I enjoy seeing these designs whenever I get the chance.

From my personal experience. It always sucks when people criticize a design a lot. I would advise you to hear it as trying to help, rather than that the design is bad or not worth pursuing. You should still listen to most of what has been said, but I think giving up on this design would be a real shame. I know of at least one instance where a company shot down an idea in a brainstorming session, and a number of years later made that one idea the most important distinguishing feature of their technology (and it still is to this day).

In my opinion FIRST would be much cooler if more teams were trying these crazy new designs, rather than just making another WCD and doing stuff purely because "its what the Einstein teams do". I hate hearing people say that a team shouldn't do something because no teams on Einstein used it. Reasons a team should use or not use those designs would be that they are what works for that team and because they would be the most effective for that challenge, not because some other really good team has done it or, the other extreme, no one else has done it.

These types of out-of-the-box designs are always fun/inspirational to design and look at. I found this design inspirational and it is a beautiful CAD model.
__________________
7 Years of FRC
"You students are at the top of the mountain, at the pinnacle of success, and what is it that you do?
You become the future guides to help others climb the mountain."

Last edited by Garret : 27-11-2012 at 00:21. Reason: clarifying
  #143   Spotlight this post!  
Unread 27-11-2012, 00:04
Cory's Avatar
Cory Cory is offline
Registered User
AKA: Cory McBride
FRC #0254 (The Cheesy Poofs)
Team Role: Engineer
 
Join Date: May 2002
Rookie Year: 2001
Location: Redwood City, CA
Posts: 6,824
Cory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond repute
Send a message via AIM to Cory
Re: Be afraid... Be VERY Afraid

Quote:
Originally Posted by Garret View Post

In my opinion FIRST would be much cooler if more teams were trying these crazy new designs, rather than just making another WCD and doing stuff purely because "its what the Einstein teams do". I hate hearing people say that a team shouldn't do something because no teams on Einstein used it. Reasons a team should use those designs would be that they are what works for that team and because they would be the most effective for that challenge, not because some other really good team has done it so let's do what they do.
There's nothing wrong with investigating "crazy new designs" from a learning perspective, the reality is just that in real life when you get a job you don't innovate for the sake of innovating, you only do it when existing solutions do not provide the solution to your problem.

Innovative is also not synonymous with good, or indicative of sound engineering. Both are important.
__________________
2001-2004: Team 100
2006-Present: Team 254
  #144   Spotlight this post!  
Unread 27-11-2012, 00:13
rcmolloy's Avatar
rcmolloy rcmolloy is offline
Remote Mentor
AKA: Robert Cory Molloy
FRC #0973 (Greybots)
Team Role: Engineer
 
Join Date: Jan 2009
Rookie Year: 2009
Location: Los Angeles, California
Posts: 425
rcmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond reputercmolloy has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

Quote:
Originally Posted by Cory View Post
There's nothing wrong with investigating "crazy new designs" from a learning perspective, the reality is just that in real life when you get a job you don't innovate for the sake of innovating, you only do it when existing solutions do not provide the solution to your problem.

Innovative is also not synonymous with good, or indicative of sound engineering. Both are important.
This has everything wrapped up in a nutshell regarding this entire thread.

Also to the original poster of the other quote, these teams aren't doing crazy designs because of their limitations and just the amount of work and effort required to realistically do some of them. Even though the crazy and novel ideas are very cool, they usually aren't the best practical ideas that you would like to go with.
__________________
FRC 1647: Iron Devils - 2009 - 2011
FRC 973: Greybots - 2011 - 20XX
"While I was a student in FIRST, it was all about becoming inspired. Now as a mentor/engineering student, it's all about making sure learn everything I can so I can carry that on inspiration for future generations while having a hell of a lot of fun!"
  #145   Spotlight this post!  
Unread 27-11-2012, 00:15
Garret's Avatar
Garret Garret is offline
Standing on the Shoulders of Giants
AKA: Garret Smalley
FRC #0691 (Hart District Robotics)
Team Role: Mentor
 
Join Date: Dec 2009
Rookie Year: 2008
Location: Goleta, CA (UCSB)
Posts: 203
Garret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond reputeGarret has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

Quote:
There's nothing wrong with investigating "crazy new designs" from a learning perspective, the reality is just that in real life when you get a job you don't innovate for the sake of innovating, you only do it when existing solutions do not provide the solution to your problem.

Innovative is also not synonymous with good, or indicative of sound engineering. Both are important.
I agree with you completely, I was more saying that people should use (or not use) designs for the right reasons.
__________________
7 Years of FRC
"You students are at the top of the mountain, at the pinnacle of success, and what is it that you do?
You become the future guides to help others climb the mountain."
  #146   Spotlight this post!  
Unread 27-11-2012, 00:20
Madison's Avatar
Madison Madison is offline
Dancing through life...
FRC #0488 (Xbot)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1999
Location: Seattle, WA
Posts: 5,244
Madison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond reputeMadison has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

Okay, I have a bit more time now that I'm not at work and can list some of the questions I have about how this would work and what the benefits are.

Years ago, I was able to receive a lot of fantastic feedback from engineers on this site, so there's definitely merit to posting ideas and soliciting feedback. That should continue, but a bit of humility goes a long way.

Questions/Concerns --

0. What problems were you trying to solve when making this design? What were the criteria you used to guide your decision making process and how did each of this model's elements satisfy that criteria?

1. Do you intend for the sphere to slip sideways against either driving roller? If not, no part of the sphere that isn't touched by a roller will ever contact the ground, so why use a sphere at all? If yes, the maximum possible force of friction between the sphere and the driving rollers must be less than the maximum force of friction between the roller and the carpet; this sacrifices available pushing force, putting your robot at a disadvantage in pushing matches.

2. The sphere is driven by a roller using friction. The available force of friction will be determined by the pneumatic cylinder pushing the roller against the sphere. You can use leverage here to make a smaller cylinder provide force that nears or exceeds your practical maximum possible friction force as determined by the coefficient of friction between your roller and sphere/sphere and carpet, but in all cases, the maximum friction force the robot can exert on the ground will be dictated by the sphere/carpet interaction.

3. When a roller is being pressed onto the surface of the sphere, because there is currently nothing shown to retain the ball from moving away from the drive rollers and ball casters, your mechanism will push the robot away from the sphere, unseating it from within the four ball casters. You will now be riding only on the thin interface between your drive roller and the sphere.
Driving forward or backward will cause the sphere to shift in the opposite direction. Any sideways motion will cause the sphere to slide sideways off the driven roller and, for lack of a better explanation, wedge itself into place between the drive rollers and two of the ball casters. You may not be able to recover from this condition except by going to a middle position that removes both rollers. The condition will repeat anytime you try to drive, however. You absolutely have to capture the sphere so that it cannot move vertically independently of the rest of the module for this to have ANY shot at working at all.

There are a lot of problems here and I think that, if you worked through them, you'd end up at a swerve module.
__________________
--Madison--

...down at the Ozdust!

Like a grand and miraculous spaceship, our planet has sailed through the universe of time. And for a brief moment, we have been among its many passengers.
  #147   Spotlight this post!  
Unread 28-11-2012, 08:22
Akash Rastogi Akash Rastogi is offline
Jim Zondag is my Spirit Animal
FRC #2170 (Titanium Tomahawks)
Team Role: Mentor
 
Join Date: Feb 2007
Rookie Year: 2006
Location: Manchester, Connecticut
Posts: 7,006
Akash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond reputeAkash Rastogi has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

Quote:
Originally Posted by Siri View Post
What's the full weight of the unit (with swerve)? And what leads you to believe the ball system will be lighter than using wheel?
Going to add to this: Why not try to further the efficiency of existing designs? If you have the capabilities to create a carbon fiber sphere correctly and within budget, why not try to mold your own wheels or other parts out of carbon fiber? (doing either one properly is pretty difficult from what I've learned in materials classes... http://helix.gatech.edu/classes/ME41...inalpaper.html)
__________________
My posts and opinions do not necessarily reflect those of my affiliated team.
['16-'xx]: Mentor FRC 2170 | ['11-'13]: Co-Founder/Mentor FRC 3929 | ['06-'10]: Student FRC 11 - MORT | ['08-'12]: Founder - EWCP (OG)

Last edited by Akash Rastogi : 28-11-2012 at 08:32.
  #148   Spotlight this post!  
Unread 28-11-2012, 21:02
cmrnpizzo14's Avatar
cmrnpizzo14 cmrnpizzo14 is offline
Registered User
AKA: Cam Pizzo
FRC #3173 (IgKNIGHTers)
Team Role: Mentor
 
Join Date: Jan 2011
Rookie Year: 2006
Location: Boston
Posts: 522
cmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond reputecmrnpizzo14 has a reputation beyond repute
Re: Be afraid... Be VERY Afraid

First off, awesome concept. I really can't believe that I just spent 30 minutes reading through all of this, but it is a fantastic concept. Your presentation of it leaves much to be desired but it's forgiven (imho).

Secondly, I have a question about the maintenance of it. If you have the balls held in place by something other than the weight of the robot (which I heavily advise!) replacing a ball will be difficult. Hopefully you will never need to actually replace one, but just in case....

Also, the actual balls you will use will possibly be carbon fiber? Carbon fiber is cool, that is not deniable. However, how will you make them to resist impact. I am no expert on carbon fiber by any stretch of the imagination, but I do know that it is fragile. In addition, your wheels are what takes the most weight on the robot. I understand that a sphere is ideal for force distribution, but I still would be worried about damage to your balls.

Lastly, if you get this to work in any way at all, please put up some sort of video of it driving. This would be amazing to see work, even if it was not in a competition. Please keep us updated!
  #149   Spotlight this post!  
Unread 15-12-2012, 09:53
RedLeader342's Avatar
RedLeader342 RedLeader342 is offline
Fabrication/Drive Coach
AKA: Justin White
FRC #0342 (Burning Magnetos)
Team Role: Mentor
 
Join Date: Mar 2010
Rookie Year: 2009
Location: Mooresville, NC
Posts: 59
RedLeader342 is a jewel in the roughRedLeader342 is a jewel in the roughRedLeader342 is a jewel in the rough
Re: Be afraid... Be VERY Afraid

it looks like the small one could be a build up wheel to the big one which then shoots a foam basketball.
__________________
2009-Mechanical and Scouting student,342
2010~12-Mechanical, Fabrication, Operator,342
2012~13- Fabrication Mentor,3196
2013~Present- Fabrication/Drive Coach, 342
  #150   Spotlight this post!  
Unread 15-12-2012, 11:54
Andrew Lawrence
 
Posts: n/a
Re: Be afraid... Be VERY Afraid

Read through the thread, Redleader. The final design was released a long yime ago.
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 23:30.

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