First let me say that my presidency of the Seattle R-word Association has been
very fun.  The SRA, which includes, The Seattle OLEF Society, The R-word-thon
committee, Western Allied R-Word, FIRST WA and VEX WA, has grown to an amazing
organization.  I really do feel that all the members have made these
organization truly amazing.

In the last year and a half we have pulled off some very large events on very
little money and each and everyone of you deserve my thanks.  Unfortunately, it
is due to these very events that other Puget Sound Societies have take notice of
us.  One in particular has decided to have it's lawyers read through out Bylaws
and the have found a small loop hole, that, in a letter I received today, has
removed me as president of the board.  Dissolved the board, and replaced it with
their own associations board.

As of noon today the SRA and affiliated members are now under the control of the
Bellevue Botanical Association.  In the letter they praise us for being an
outstanding organization and wish not to make many changes.  However the changes
that they are going to make are:

1.The use of the R-word is banned.  The R-word is replaced with either the
R-word, or Our Little Electronic Friends (OLEF).

2.All power sources must be of renewable food acids, copper and zinc rods.  To
this end each of WAR's 30 pound R-words will have to be powered by 600 pounds of
lemons per match.

3.The use of plastic is banned and wood shall be used in it's place.  They are
switching FIRST Lego League to FIRST Lincoln Log League (FLLL)

4.Most of R-word-thon's contests will need to be re-worked.
     a.Magellan has been replaced with a 5cm by 5cm course in which snails will
have to find rocks.
     b.The sumo ring is now 4 inches round for the slug wrestling.  This will
allow us to have 25 matches running at the same time, which will we need since
each match now lasts an hour.
     c.Humming Bird Feeder Frenzy, in which contestants will build the most
attractive humming bird feeders.  During the contest we will release 20,000
humming birds into the Center House and the feeder with the lease amount of
water in it at the end of the day is the winner.

5.The SRS presentations will take on a bit of a change.  From now on speakers
can only be chosen from Biology and Horticultural departments of colleges.

Again let me say it was my pleasure being your president and I hope our new set
of leaders take us into a bright new future (of mostly outdoor activities).

-Jim Wright

20,000 hummingbirds should be able to power a few R-words for more than 15
minutes!
    Kevin.


-----Original Message-----
>From: Mike Payson <mike@...>
>Sent: Apr 2, 2010 12:07 AM
>To: SeattleRobotics@yahoogroups.com
>Subject: Re: [SeattleRobotics] Sad news from your ex-president of the SRA 
board
>
>So, based on this new mission, I think the oft-maligned 15 minute battery
>discussion is suddenly appropriate. Can I suggest that the first speaker for
>our newly rebranded organization be an expert on biorenewable power sources?
>
>On Thu, Apr 1, 2010 at 9:04 PM, Erik Knise <elknise@...> wrote:
>
>>
>>
>> Thanks Jim, great info!
>>
>> Hope to see you at the next meeting,
>>
>> --
>> Erik L. Knise
>> Pacific Shipping Company
>> Seattle, WA
>>
>>
>>

One question. Please clarify the new definition of legs for the
legged R-word contest.

I'm trying to teach my pet snail "slimey" to conform to the rules.
Unfortunately, he has only one foot and no legs, so I'm not sure what
to tell him.
He gets confused about the definition of rotary motion.

Larry


On Apr 1, 2010, at 8:50 PM, Jim wrote:

> First let me say that my presidency of the Seattle R-word
> Association has been very fun.  The SRA, which includes, The
> Seattle OLEF Society, The R-word-thon committee, Western Allied R-
> Word, FIRST WA and VEX WA, has grown to an amazing organization.  I
> really do feel that all the members have made these organization
> truly amazing.
>
> In the last year and a half we have pulled off some very large
> events on very little money and each and everyone of you deserve my
> thanks.  Unfortunately, it is due to these very events that other
> Puget Sound Societies have take notice of us.  One in particular
> has decided to have it's lawyers read through out Bylaws and the
> have found a small loop hole, that, in a letter I received today,
> has removed me as president of the board.  Dissolved the board, and
> replaced it with their own associations board.
>
> As of noon today the SRA and affiliated members are now under the
> control of the Bellevue Botanical Association.  In the letter they
> praise us for being an outstanding organization and wish not to
> make many changes.  However the changes that they are going to make
> are:
>
> 1.The use of the R-word is banned.  The R-word is replaced with
> either the R-word, or Our Little Electronic Friends (OLEF).
>
> 2.All power sources must be of renewable food acids, copper and
> zinc rods.  To this end each of WAR's 30 pound R-words will have to
> be powered by 600 pounds of lemons per match.
>
> 3.The use of plastic is banned and wood shall be used in it's
> place.  They are switching FIRST Lego League to FIRST Lincoln Log
> League (FLLL)
>
> 4.Most of R-word-thon's contests will need to be re-worked.
>     a.Magellan has been replaced with a 5cm by 5cm course in which
> snails will have to find rocks.
>     b.The sumo ring is now 4 inches round for the slug wrestling.
> This will allow us to have 25 matches running at the same time,
> which will we need since each match now lasts an hour.
>     c.Humming Bird Feeder Frenzy, in which contestants will build
> the most attractive humming bird feeders.  During the contest we
> will release 20,000 humming birds into the Center House and the
> feeder with the lease amount of water in it at the end of the day
> is the winner.
>
> 5.The SRS presentations will take on a bit of a change.  From now
> on speakers can only be chosen from Biology and Horticultural
> departments of colleges.
>
> Again let me say it was my pleasure being your president and I hope
> our new set of leaders take us into a bright new future (of mostly
> outdoor activities).
>
> -Jim Wright
>
>
>
>
> ------------------------------------
>
> Visit the SRS Website at http://www.seattlerobotics.orgYahoo!
> Groups Links
>
>
>

2010/4/2 Kevin Rock <kevinrock@...>
> 20,000 hummingbirds should be able to power a few R-words for more than 15
minutes!
> Kevin.

Unless the wings had 6 DOF ;)


> -----Original Message-----
> >From: Mike Payson <mike@...>
> >Sent: Apr 2, 2010 12:07 AM
> >To: SeattleRobotics@yahoogroups.com
> >Subject: Re: [SeattleRobotics] Sad news from your ex-president of the SRA
board
> >
> >So, based on this new mission, I think the oft-maligned 15 minute battery
> >discussion is suddenly appropriate. Can I suggest that the first speaker for
> >our newly rebranded organization be an expert on biorenewable power sources?
> >
> >On Thu, Apr 1, 2010 at 9:04 PM, Erik Knise <elknise@...> wrote:
> >
> >>
> >>
> >> Thanks Jim, great info!
> >>
> >> Hope to see you at the next meeting,
> >>
> >> --
> >> Erik L. Knise
> >> Pacific Shipping Company
> >> Seattle, WA
> >>
> >>
> >>
>
>

Mini-Sumo Ship-In's at UNI! on again for fifth year!

What better example of showing your robots have matured, than
you send them off to compete in a contest on their own, and then
watch the Live Webcast as they "duke it out" with other robots
from our students and this and other countries Ship-Ins. And if
you've seen the previous matches, you know we get some very
careful and dilligent assistants to prepare, place and operate
your robots per your written instructions.

We've got a new web site you can see the past 4 years recordings
on if you wish.

http://narobotics.org/

Here's a way to send your robot into combat, and have its
appearance documented for the foreseeable future! ("I'll make ya
famous!") You too can have your robot immortalized by entering
it in this competition.

So get ready and send in those challengers. Remember, there's a
cap on how many competitors will be accepted (12) so enter as
soon as you can. Details for shipping and entry form on the web
site:

http://narobotics.org/how-ship-your-sumo-robot-april-29-2010-uni
-mini-sumo-invitational

Come on and Ship-In those Mini-Sumos!

Randy

> BTW the results, for people who might have missed the events, are posted
> here:
> http://www.robothon.org/robothon/results.php

Are there photos or videos?

Peter

Hi Peter,

Yes there are photos! Rich Harman made his photo collection available here:
http://modelstation.smugmug.com/Events/Robothon-2009

(this is also posted to the front page at the Robothon website)

Bob Cook

On 2010-04-05, at 3:59 AM, Peter Balch wrote:

>> BTW the results, for people who might have missed the events, are posted
>> here:
>> http://www.robothon.org/robothon/results.php
>
> Are there photos or videos?
>
> Peter

> Yes there are photos! Rich Harman made his photo collection available
> here:
> http://modelstation.smugmug.com/Events/Robothon-2009

Thanks. It looks like it was a wondeful event.

Peter

On 2010-04-05, at 11:30 AM, Peter Balch wrote:

>> Yes there are photos! Rich Harman made his photo collection available
>> here:
>> http://modelstation.smugmug.com/Events/Robothon-2009
>
> Thanks. It looks like it was a wondeful event.
>

Glad you thought so, I think everyone who attended had fun. There are regular
flights from your side of the world to ours, perhaps you should come to the next
Robothon in October! I would love to see some of your projects up close and I'm
certain there are many others who would as well.

Bob Cook

http://www.sri.com/rd/electroadhesion.html

When first read about the SRI electroadhesion robot, I wondered (like most
people I suppose) what sort of voltage it was using. They were claiming 0.5
to 1.5 N/sq.cm which seemed huge.

So lets do some back-of-the-envelope calculations. I'm sure someone will
correct me if I get it wrong.

The force between the plates of a capacitor is

F = permittivity  * A * V^2 / (2 * d^2)

A is area; V is voltage; d is separation of the plates.

The permittivity of air is around 8.85e-12

Assume that the robot's adhesion plate is a square of side L; then
rearranging:

V = d/L *sqrt(2*F/permittivity)

If we need a force of 1kg weight (10N) then

V = d/L * sqrt(20/permittivity)
V = d/L * 1,500,000

If L 20cm and d = 0.1mm then

V = 0.0001/0.2 *1,500,000
V=750

750 Volts is achievable relatively easily but getting the separation of the
adhesion plate from the wall to be 0.1mm is quite hard.

Presumably, the adhesion plate is a conductive sheet covered in an
insulator. How thick must the insulator be? It can't be too thin or its
insulation will break down. It can't be thick or d gets too big (assume a
relative permittivity of the insulator of 3 to 4).

SRI claim 1N/sq.cm, so V = 4.7kV if d=0.1mm. Either they're using a big
voltage or they're managing a much smaller separation.

Peter

Here is an Instructable for hacking the H-Bridge of the Thunder Tumbler:
http://www.instructables.com/id/Robot-Platform-including-h-bridges-from-10-RC-Ca\
/


--- In SeattleRobotics@yahoogroups.com, Steve Kozachik <steve_kozachik@...>
wrote:
>
> I am working on a project to re-purpose 5 Thunder Tumblers into photovores for
a kids' robot club project.  They are currently radio controlled with dual drive
steering.  I want to identify the pins in the IC controlling the
H-Bridge/motors, remove the IC chip and hookup a simple photoresistor circuit to
follow the light. I would prefer not to have to fund and build 5 each H-Bridges
if I can easily re-use existing.
>
> Searching has found lots of examples of similar projects, lots and lots of
H-Bridge circuits but nothing too helpful to a novice on figuring out which pins
directly control the motor direction/speed.  What I am looking for is a tutorial
of somesort.  Any suggestions?
>
> I plan to be at the next Meeting on the 17th with the toys, and a suitably
puzzled look on my face, staying for the robot building session after the
meeting.
>
> Here is a cute video of the un-hacked toy in the hands of a youngster having
some serious fun:
>
> http://www.youtube.com/watch?v=ZNDUTJ481Pw
>
>
> Steve K.
>

What I did for this, which is perhaps dumb, was simply to use an ohm meter to trace out the circuitry, reverse engineering a schematic. Once I had the schematic it was obvious which pins were controlling the h-bridge.

David

On Apr 7, 2010, at 5:21 PM, Steve Kozachik wrote:

I am working on a project to re-purpose 5 Thunder Tumblers into photovores for a kids' robot club project.  They are currently radio controlled with dual drive steering.  I want to identify the pins in the IC controlling the H-Bridge/motors, remove the IC chip and hookup a simple photoresistor circuit to follow the light. I would prefer not to have to fund and build 5 each H-Bridges if I can easily re-use existing.

 

Searching has found lots of examples of similar projects, lots and lots of H-Bridge circuits but nothing too helpful to a novice on figuring out which pins directly control the motor direction/speed.  What I am looking for is a tutorial of somesort.  Any suggestions?

 

I plan to be at the next Meeting on the 17th with the toys, and a suitably puzzled look on my face, staying for the robot building session after the meeting.

 

Here is a cute video of the un-hacked toy in the hands of a youngster having some serious fun:

 

http://www.youtube .com/watch?v=ZNDUTJ481Pw

 

 

Steve K.

Hmmmm... Interesting calculation. Since current is not really an issue here
(other than that which would leak), I suppose it is possible to crank the
voltage up to something obscene to get the adhesion. That would help with
the separation to some degree.

If you think about it, 'static cling' has a ridiculously high voltage with
little current capacity.

--------------------------------------------------
From: "Peter Balch" <peterbalch@...>
Sent: Thursday, April 08, 2010 3:17 AM
To: <SeattleRobotics@yahoogroups.com>
Subject: [SeattleRobotics] electroadhesion

> http://www.sri.com/rd/electroadhesion.html
>
> When first read about the SRI electroadhesion robot, I wondered (like most
> people I suppose) what sort of voltage it was using. They were claiming
> 0.5
> to 1.5 N/sq.cm which seemed huge.
>
> So lets do some back-of-the-envelope calculations. I'm sure someone will
> correct me if I get it wrong.
>
> The force between the plates of a capacitor is
>
> F = permittivity  * A * V^2 / (2 * d^2)
>
> A is area; V is voltage; d is separation of the plates.
>
> The permittivity of air is around 8.85e-12
>
> Assume that the robot's adhesion plate is a square of side L; then
> rearranging:
>
> V = d/L *sqrt(2*F/permittivity)
>
> If we need a force of 1kg weight (10N) then
>
> V = d/L * sqrt(20/permittivity)
> V = d/L * 1,500,000
>
> If L 20cm and d = 0.1mm then
>
> V = 0.0001/0.2 *1,500,000
> V=750
>
> 750 Volts is achievable relatively easily but getting the separation of
> the
> adhesion plate from the wall to be 0.1mm is quite hard.
>
> Presumably, the adhesion plate is a conductive sheet covered in an
> insulator. How thick must the insulator be? It can't be too thin or its
> insulation will break down. It can't be thick or d gets too big (assume a
> relative permittivity of the insulator of 3 to 4).
>
> SRI claim 1N/sq.cm, so V = 4.7kV if d=0.1mm. Either they're using a big
> voltage or they're managing a much smaller separation.
>
> Peter
>
>
>
> ------------------------------------
>
> Visit the SRS Website at http://www.seattlerobotics.orgYahoo! Groups Links
>
>
>
>