Go to Post A well learned individual knows themselves and how to collect and use the tool of knowledge. - techhelpbb [more]
Home
Go Back   Chief Delphi > Technical > Motors
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
  #16   Spotlight this post!  
Unread 25-08-2011, 13:29
JesseK's Avatar
JesseK JesseK is online now
Expert Flybot Crasher
FRC #1885 (ILITE)
Team Role: Mentor
 
Join Date: Mar 2007
Rookie Year: 2005
Location: Reston, VA
Posts: 3,722
JesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond repute
Re: 2012 motors?

Quote:
Originally Posted by AdamHeard View Post
If you have a lot of 500 sized motors left, whats to stop people from putting multiple sets in drive and getting ridiculously powerful drivetrains?

Even if teams did end up only going with 2 cims per drive, isn't that the new standard then? and pinning/pushing will still happen?
CIMs can get closer to stall conditions multiple times before burning out. We've had BB550's & 775's smoke after a few iterations of running them around 30-35 amps for prototype lifts. I'm a bit smarter now than I was then so I can calculate for some safety margins, but for a drive train I don't think there's enough safety margin for these motors.

I think, iirc, 25 tried 2 BB550's + 2 CIMs in '08, and said they had to replace the 550's a couple of times. I think they wound up going down to 2 CIMs only in Atlanta? I could be mistaken.

Of course, I could totally be missing something; I wasn't around for the drill motors of '04 so I don't know how many of those burned out on field.
__________________

Drive Coach, 1885 (2007-present)
CAD Library Updated 5/1/16 - 2016 Curie/Carver Industrial Design Winner
GitHub
  #17   Spotlight this post!  
Unread 25-08-2011, 15:24
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: 1,190
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: 2012 motors?

Quote:
Originally Posted by JesseK View Post
CIMs can get closer to stall conditions multiple times before burning out. We've had BB550's & 775's smoke after a few iterations of running them around 30-35 amps for prototype lifts. I'm a bit smarter now than I was then so I can calculate for some safety margins, but for a drive train I don't think there's enough safety margin for these motors.

I think, iirc, 25 tried 2 BB550's + 2 CIMs in '08, and said they had to replace the 550's a couple of times. I think they wound up going down to 2 CIMs only in Atlanta? I could be mistaken.

Of course, I could totally be missing something; I wasn't around for the drill motors of '04 so I don't know how many of those burned out on field.
Smaller motors , by nature, have issues dissipating heat. CIMS, due to their large size, can be run closer to stall because they can dissipate the associated heat.

A non-defective 775 should be better at running at or near stall for limited periods of time, unlike the 500 series, since, once again, its larger size can dissipate the heat that results from inefficient operation, but if there is an internal short, the resistance is less than it would normally be and the current can exceed the rated stall current producing more heat faster than the motor can dissipate it which eventually breaks down the enamel insulation on the wires and causes more shorts which causes more heating and, if it allowed to continue, the motor could potentially catch on fire.

500 series motors are much more susceptible to overheating. Their small size prevents them from dissipating much heat at all passively. Instead, they rely on internal fans to actively cool the armature. 500 series motors, as a result, will overheat if they even get close to stalling. It is best to allow 500 series motors run fast and gear them to the desired speed.
__________________
  #18   Spotlight this post!  
Unread 25-08-2011, 15:35
JamesCH95's Avatar
JamesCH95 JamesCH95 is online now
Hardcore Dork
AKA: JCH
FRC #0095 (The Grasshoppers)
Team Role: Engineer
 
Join Date: Dec 2004
Rookie Year: 2001
Location: Enfield, NH
Posts: 1,890
JamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond repute
Re: 2012 motors?

Quote:
Originally Posted by Hawiian Cadder View Post
I hope we get better motors this year. 4 cims, 4 FP, 4 window, 4 tiny motors (395's or something similar)

keep it simple.
What motors did you dislike last year?

The RS775-18 was an awesome motor, and with the ability to use 4 of them there was plenty of power on tap for many applications, including stalled-motor setups. We had two 775s on our arm (see pic below) that routinely stalled and were fine. It only took a few watts at stall for each motor to maintain position, FWIW.

__________________
Theory is a nice place, I'd like to go there one day, I hear everything works there.

Maturity is knowing you were an idiot, common sense is trying to not be an idiot, wisdom is knowing that you will still be an idiot.
  #19   Spotlight this post!  
Unread 25-08-2011, 15:50
lemiant's Avatar
lemiant lemiant is offline
the Dreamer
AKA: Alex
FRC #4334 (Alberta Tech Alliance)
Team Role: Leadership
 
Join Date: Feb 2009
Rookie Year: 2008
Location: Calgary, AB, Canada
Posts: 562
lemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond repute
Re: 2012 motors?

Quote:
Originally Posted by PAR_WIG1350 View Post
Smaller motors , by nature, have issues dissipating heat. CIMS, due to their large size, can be run closer to stall because they can dissipate the associated heat.
I don't understand this. If power consumption is linearly related to volume then maximum heat production increases in a cubic curve, while maximum heat dissipation is quadratic, thus a larger motor actually has a harder time dissipating heat.
What makes larger motors better at dissipating heat?
  #20   Spotlight this post!  
Unread 25-08-2011, 15:54
AdamHeard's Avatar
AdamHeard AdamHeard is offline
Lead Mentor
FRC #0973 (Greybots)
Team Role: Mentor
 
Join Date: Oct 2004
Rookie Year: 2004
Location: Atascadero
Posts: 5,526
AdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond repute
Send a message via AIM to AdamHeard
Re: 2012 motors?

Quote:
Originally Posted by lemiant View Post
I don't understand this. If power consumption is linearly related to volume then maximum heat production increases in a cubic curve, while maximum heat dissipation is quadratic, thus a larger motor actually has a harder time dissipating heat.
What makes larger motors better at dissipating heat?
I think he's making the case where the motors are the same power, but only differ size. Which was pretty true when comparing the 550/775 and FP this year.
  #21   Spotlight this post!  
Unread 25-08-2011, 16:36
JamesCH95's Avatar
JamesCH95 JamesCH95 is online now
Hardcore Dork
AKA: JCH
FRC #0095 (The Grasshoppers)
Team Role: Engineer
 
Join Date: Dec 2004
Rookie Year: 2001
Location: Enfield, NH
Posts: 1,890
JamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond reputeJamesCH95 has a reputation beyond repute
Re: 2012 motors?

Quote:
Originally Posted by lemiant View Post
I don't understand this. If power consumption is linearly related to volume then maximum heat production increases in a cubic curve, while maximum heat dissipation is quadratic, thus a larger motor actually has a harder time dissipating heat.
What makes larger motors better at dissipating heat?
The virtue of the CIM is it's tremendous thermal inertia. It weighs about 2.8lbs whereas the next largest motor (RS775-18) is about 0.7lbs. This allows the CIM to absorb much more heat than any other motor in the kit. In a 2m:15s match it can usually get by no problem.

It also has an aluminum case that probably helps conduct heat away quite nicely, better than the steel cases on most of the smaller motors anyway. They're also bolted to other big pieces of aluminum (tough boxes for one) that are great heat-sinks.

On our arm, there were two RS775-18s, one in a dewalt transmission (plastic) one in a bane-bots transmission (aluminum and steel). The one in the bane-bots transmission ran noticably cooler because it dissipated heat through the transmission well. We did thermographics to confirm:

__________________
Theory is a nice place, I'd like to go there one day, I hear everything works there.

Maturity is knowing you were an idiot, common sense is trying to not be an idiot, wisdom is knowing that you will still be an idiot.
  #22   Spotlight this post!  
Unread 25-08-2011, 16:41
Andrew Schreiber Andrew Schreiber is offline
Joining the 900 Meme Team
FRC #0079
 
Join Date: Jan 2005
Rookie Year: 2000
Location: Misplaced Michigander
Posts: 4,079
Andrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond repute
Re: 2012 motors?

Quote:
Originally Posted by JesseK View Post
Heh, if they wanted to reduce the number of pinning/pushing matches, they could take us down to 2 CIMs max with plenty of 500-sized options available with other motors.

Let the magic smoke commence!
Or they could write the game in such a way that such behavior is naturally discouraged. In a perfect world defense would not be a viable strategy due to multiple methods of scoring being more valuable (RP/QP/Score etc) without having to rely on clunky penalties to enforce gameplay.

Al, I also have to ask: Does anyone know if the GDC and the KOP Engineers coordinate to make sure that the game is tailored to what motors we have available and vice versa?
__________________




.
  #23   Spotlight this post!  
Unread 25-08-2011, 17:15
thefro526's Avatar
thefro526 thefro526 is offline
Mentor for Hire.
AKA: Dustin Benedict
no team (EWCP, MAR, FRC 708)
Team Role: Mentor
 
Join Date: Aug 2006
Rookie Year: 2005
Location: New Jersey
Posts: 2,599
thefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond reputethefro526 has a reputation beyond repute
Send a message via AIM to thefro526 Send a message via MSN to thefro526
Re: 2012 motors?

I have heard talk of removing the CIM motor from the KOP in 2012 - which may be why AM has them on sale. I'm not sure whether or not this is true, but I've been playing with some other ideas for power since I've heard this.

I would say that Window Motors are almost definitely a guarantee, along with some sort of 500-series or 700-series Mabuchi/Banebots motor.
__________________
-Dustin Benedict
2005-2012 - Student & Mentor FRC 816
2012-2014 - Technical Mentor, 2014 Drive Coach FRC 341
Current - Mentor FRC 2729, FRC 708
  #24   Spotlight this post!  
Unread 25-08-2011, 17:19
Andrew Schreiber Andrew Schreiber is offline
Joining the 900 Meme Team
FRC #0079
 
Join Date: Jan 2005
Rookie Year: 2000
Location: Misplaced Michigander
Posts: 4,079
Andrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond reputeAndrew Schreiber has a reputation beyond repute
Re: 2012 motors?

Quote:
Originally Posted by thefro526 View Post
I have heard talk of removing the CIM motor from the KOP in 2012 - which may be why AM has them on sale. I'm not sure whether or not this is true, but I've been playing with some other ideas for power since I've heard this.

I would say that Window Motors are almost definitely a guarantee, along with some sort of 500-series or 700-series Mabuchi/Banebots motor.
Perfect... every year my dream of 6 hamster powered robots on a field comes closer to reality! Imagine the overwhelming cuteness!
__________________




.
  #25   Spotlight this post!  
Unread 25-08-2011, 17:38
AdamHeard's Avatar
AdamHeard AdamHeard is offline
Lead Mentor
FRC #0973 (Greybots)
Team Role: Mentor
 
Join Date: Oct 2004
Rookie Year: 2004
Location: Atascadero
Posts: 5,526
AdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond repute
Send a message via AIM to AdamHeard
Re: 2012 motors?

Quote:
Originally Posted by thefro526 View Post
I have heard talk of removing the CIM motor from the KOP in 2012 - which may be why AM has them on sale. I'm not sure whether or not this is true, but I've been playing with some other ideas for power since I've heard this.

I would say that Window Motors are almost definitely a guarantee, along with some sort of 500-series or 700-series Mabuchi/Banebots motor.
Talk from who?
  #26   Spotlight this post!  
Unread 25-08-2011, 18:06
AlexH AlexH is offline
Registered User
no team
Team Role: College Student
 
Join Date: Sep 2010
Rookie Year: 2010
Location: PA
Posts: 215
AlexH is a name known to allAlexH is a name known to allAlexH is a name known to allAlexH is a name known to allAlexH is a name known to allAlexH is a name known to all
Re: 2012 motors?

Quote:
Originally Posted by lemiant View Post
I don't understand this. If power consumption is linearly related to volume then maximum heat production increases in a cubic curve, while maximum heat dissipation is quadratic, thus a larger motor actually has a harder time dissipating heat.
What makes larger motors better at dissipating heat?
The larger motor casing works better as a heat sink.
__________________
My Instructables
  #27   Spotlight this post!  
Unread 25-08-2011, 19:42
s1900ahon s1900ahon is offline
Registered User
AKA: Scott McMahon
FRC #2468 (Appreciate)
Team Role: Mentor
 
Join Date: May 2008
Rookie Year: 2008
Location: Austin, TX
Posts: 156
s1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant futures1900ahon has a brilliant future
Re: 2012 motors?

Quote:
Originally Posted by Andrew Schreiber View Post
Al, I also have to ask: Does anyone know if the GDC and the KOP Engineers coordinate to make sure that the game is tailored to what motors we have available and vice versa?
I can say for certain that the KoP team is aware of the GDC musings.
  #28   Spotlight this post!  
Unread 25-08-2011, 22:20
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1996
Location: Wheeling, IL
Posts: 10,798
Al Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond repute
Re: 2012 motors?

Quote:
Originally Posted by Andrew Schreiber View Post
Al, I also have to ask: Does anyone know if the GDC and the KOP Engineers coordinate to make sure that the game is tailored to what motors we have available and vice versa?

Andrew,
Not to my knowledge. If you take a long look back at previous games, none depended on a specific motor for play. If you check (I have, obviously) you will see many winning robots over the years that had only a few of the available motors. I think one year, a robot had only three motors total. While I have several favorites that are no longer part of the KOP, there other ways to skin a cat.

I can tell you this, the KOP engineers work for Bill and Bill is part of the GDC. Kate is a KOP engineer and on the GDC. You can draw your own conclusions on the discussions across lunch and coffee in the office. I don't know how the GDC operates during game design but I would expect them at some point to build a couple of prototypes to see if their ideas actually work in practice. We really haven't had a game that couldn't be played yet so they must be doing something right.

All we really have to know is that all teams get the chance to use the same subset of motors each year. As to the rumor about the CIMs being dropped, I won't get excited until that Saturday afternoon after New Years. Remember that even if I did know the real answer I can't and wouldn't tell you. The same for the folks at AndyMark. We play by the same rules.

As to the other discussion, you need to keep in mind the power curves, operating choices and peak efficiencies. You can obviously make an FP work efficiently and make more power than a CIM run way off the curve and heating up. Remember too, the motor windings is where the I^2 * R losses mount. In every motor we use, the path for that heat is through the shaft and bearings or through radiation across the gap to the magnet structure. In some of the smaller motors, a fan moves air through the gap/armature and carries away some heat. In the CIM the case is sealed so no air moves to pull heat out of the case.
__________________
Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
________________________
Storming the Tower since 1996.

Last edited by Al Skierkiewicz : 25-08-2011 at 22:27.
  #29   Spotlight this post!  
Unread 26-08-2011, 10:18
ayeckley's Avatar
ayeckley ayeckley is offline
Registered User
AKA: Alex Yeckley
FRC #2252 (Mavericks)
Team Role: Mentor
 
Join Date: Apr 2007
Rookie Year: 2007
Location: Sandusky, OH
Posts: 268
ayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond reputeayeckley has a reputation beyond repute
Re: 2012 motors?

Quote:
Originally Posted by thefro526 View Post
I have heard talk of removing the CIM motor from the KOP in 2012 - which may be why AM has them on sale.
I asked the AndyMark rep at IRI if they were discounting them in anticipation of no longer being FRC-legal. He said they were simply trying to move inventory.

If AM knew that they weren't going to be provided in the KOP for 2012 (but still FRC-legal), then the *last* thing they would do (from a for-profit business perspective) would be to put them on sale in the preceding off-season.

I'm betting/hoping that they will be legal in 2012, and still in the KOP.
__________________

  #30   Spotlight this post!  
Unread 26-08-2011, 11:30
lemiant's Avatar
lemiant lemiant is offline
the Dreamer
AKA: Alex
FRC #4334 (Alberta Tech Alliance)
Team Role: Leadership
 
Join Date: Feb 2009
Rookie Year: 2008
Location: Calgary, AB, Canada
Posts: 562
lemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond reputelemiant has a reputation beyond repute
Smile Re: 2012 motors?

Quote:
Originally Posted by ayeckley View Post
I asked the AndyMark rep at IRI if they were discounting them in anticipation of no longer being FRC-legal. He said they were simply trying to move inventory.

If AM knew that they weren't going to be provided in the KOP for 2012 (but still FRC-legal), then the *last* thing they would do (from a for-profit business perspective) would be to put them on sale in the preceding off-season.

I'm betting/hoping that they will be legal in 2012, and still in the KOP.
What else is the AM rep going to say? I doubt confidential knowledge goes that deep, and even if he did know they were going to be removed from the kit he couldn't exactly tell you
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 15:15.

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