From Thu Jul  3 16:26:58 1997
Received: from ( []) by (8.6.12/8.6.12) with ESMTP id QAA14973 for <>; Thu, 3 Jul 1997 16:26:57 -0400
Received: from ( [])
	by (8.8.5/8.8.5) with ESMTP id QAA15354
	for <>; Thu, 3 Jul 1997 16:14:24 -0400 (EDT)
Received: from ( [])
	by (8.8.5/8.8.5) with ESMTP id QAA05003
	for <>; Thu, 3 Jul 1997 16:14:23 -0400 (EDT)
Received: (from majordomo@localhost) by (8.8.4/8.6.9) id QAA12914 for aaai97-outgoing; Thu, 3 Jul 1997 16:01:11 -0400 (EDT)
Received: from ( []) by (8.8.4/8.6.9) with ESMTP id QAA12887; Thu, 3 Jul 1997 16:00:59 -0400 (EDT)
Received: from ( [])
          by (8.8.4/8.8.4) with ESMTP
	  id NAA13849; Thu, 3 Jul 1997 13:00:44 -0700
Received: (from rsargent@localhost)
	by (8.8.5/8.8.5) id MAA01609;
	Thu, 3 Jul 1997 12:58:54 -0700
Date: Thu, 3 Jul 1997 12:58:54 -0700
Message-Id: <>
From: Randy Sargent <>
To: Chris Cantor <>, Reid Simmons <>
Subject: Re: pen for find life on mars event? 
Precedence: bulk
Status: RO

> > As we design this, we need to know if the lip on the pen be removed so that
> > we can push the martians in, or if teams have an option of a lip/door
> > configuration?

> On that subject, we are currently designing the pen: The rules state that
> the lip is to be ~5cm (~2").  That's pretty high, in my mind.  We can
> easily make it lower, and still ensure that the squiggle balls will not
> escape (I don't know how low -- our squiggle balls come in on Monday and we
> can test it then).  The question is: Does anyone have a problem with
> lowering the lip height?  If anyone does, I'll keep it the same (since
> that's what the rules state), but if there are no problems with it, we'll
> lower it to the minimum needed.

We had a similar problem in the tennis ball competition last year -- we
needed to keep the lip low for our gripper, but high enough to keep
squiggle balls from sneaking in or out.  We found that 1" "L" aluminum
stock from the hardware store was enough to keep the squiggle balls from
jumping over (placed with a flat part on the ground, so it was 1" high).
We taped the L stock to the floor.

If a robot does need to push (rather than lift) a ball over a 1" lip, I
think it might be possible with a properly shaped pushing surface (shaped
so the ball slides up when it gets caught against something in the front).

-- Randy

Randy Sargent                        Newton Research Labs
Senior Design Engineer               Robotic Systems and Software