DPRG mailing list archives: [DPRG] RE: .Parallax Robot

Sun Jan 6 03:17:16 CST 2008

Kenneth Maxon wrote:
> 
> Hi Jeff,
> 
> It sounds like we have a common design goal, an APU to allow extended run
> time / loiter for long haul robotics that doesn't keep the neighborhood
> children awake when returning home on a late summer evening...

My third design even had electric start. That way I figured that if it 
detected the batteries were low that it could start the engine and 
provide extra power. It has an EV Warrior motor (like the smaller 
BattleBots used). The motor can act as a starter motor or generator.

> Odd that
> I've never made it to a TCRG meeting or competition and I have made it to a
> DPRG competition.   The Oddness comes that I live only a few hours south of
> you guys.

Not so odd that you haven't made it to one of our competitions... We 
can't get enough interest or coordination to have an actual competition. 
We have atteneded a couple of shows for the Science Museum and a few 
appearances at schools.

> The APU work is definitely in the plans for my Sojourner robot project.   I
> had decided to develop it as a tow behind cart for use with ProtoBot and
> then to integrate it on the Sojourner platform.

I saw that you stated you were going to convert your 2-cycle engine to 
"full compression diesel". Is that still the plan? Why would you want to 
do that? Just because you can? ;-) Is that diesel fuel from the gas 
station or R/C glow plug fuel?

(I was searching your web site to see if that statement was still there. 
It is. And I found my Earth Explorer robot on your web site! I'm honored!)

> I don't know if you still attend TCRG meetings

I try to go every month.

> but possibly we should pick
> one that I could head up for so that we can chat.   It is just far enough
> that given the Thursday night timing I'd have to take a Friday off and leave
> work extra early on Thursday to make it...

Everybody up here would love to have you at a meeting and exchange 
ideas. If ProtoBot wants to come too, that would be great!

Another option would be Robot Shop of Horrors:
http://www.sampson-jeff.com/rsoh/
We still meet most Friday nights at Alan's house if we don't have a 
meeting that week. RSOH is kind of like the Dallas RBNO. Except we don't 
have a luxurious World Headquarters to meet at. (Man, that warehouse 
really looks sweet now. I have thought several times about moving to 
Dallas :)

-- 
Jeff Sampson
http://tcrobots.org/members/jsamp.htm

> I am headed out to CES this week
> (this morning) so I'll be a little slow on e-mail responses during the
> week...
> 
> -Kenneth
> 
> 
> -----Original Message-----
> From: dprglist-bounces at dprg.org [mailto:dprglist-bounces at dprg.org]On
> Behalf Of Jeff Sampson
> Sent: Sunday, January 06, 2008 2:08 AM
> To: dprglist at dprg.org
> Subject: [DPRG] RE: .Parallax Robot
> 
> 
> Hi Kenneth, Ron and Glenn,
> 
> This talk of quiet small engines got me curious. I have made three
> attempts at a gasoline power generator.
> First attempt:
> http://www.sampson-jeff.com/eep/eep3.htm
> Second attempt:
> http://www.sampson-jeff.com/eep/eep9.htm
> Third attempt:
> http://www.sampson-jeff.com/rsoh/031024/
> http://tcrobots.org/mtgpics/2003/0312.htm
> 
> The first and second versions actually ran. Number one was too big.
> Number three sheared a steel pin on the motor and the engine developed
> mechanical problems. But yes, they were both too loud.
> 
> So I did some quick searching and found various links to tuned exhaust
> information, animations and programs to do calculations.
> 
> This page has purchased software and a link to free progam:
> http://www.bevenyoung.com.au/mota.htm
> 
> The last message on this page gives links to wikipedia and How Stuff Works:
> http://www.motoredbikes.com/showthread.php?t=4352
> 
> The wikipedia link has animations and software and links to other sites:
> http://en.wikipedia.org/wiki/Expansion_chamber
> 
> This link from wikipedia has silencer tuned exhaust:
> http://seniordesign.engr.uidaho.edu/2003_2004/SPR/snapshot%20-%20exp.%20cham
> ber.htm
> 
> So these are some good places to start if anyone is interested in using
> gas engines for robots. It will give me something else to work on, if I
> run out of other things to do. ;-)
> 
> --
> Jeff Sampson
> http://tcrobots.org/members/jsamp.htm
> 
> Kenneth Maxon wrote:
> 
> 
>>One company out there that makes this sort of mufflers that can be
> 
> modified
> 
>>to tune for standing wave noise cancellation can be found at the following
>>link.
>>
>>http://davisdieseldevelopment.com/muffler/giant.htm
> 