Posted by aTm at 1/10/2001 11:50 PM EST
Student on team #111, Wildstang, from Wheeling High School and Motorola.
I realize that there is most likely a very small number of teams that already have that evil ramp built AND two accurate goals, but I know that there has to be at least one 2001 field already in existence out there. Or at least I hope so, because as I’m sure that most of you have now recognized, there are many strategies/designs/concepts/ideas/whatever that simply cannot be followed further OR thrown out simply because WE DO NOT KNOW! Example: how hard is it to push two goals back to back up the ramp? how hard is it to pick up the goal? can two goals be stacked somehow sideways on the ramp since they obviously cannot fit side-to-side. These are just a couple questions, and any general impressions of the field/goals/ramp that are completed would be GREATLY appreciated by I’m sure much of the forum. As for Wildstang, we will most likely have most of the field constructed within a matter of days, so I will gladly convey any impressions myself or the rest of my team comes up with once the field is completed. Thanks in advance to anyone that has experienced the 2001 field.
aTm
Posted by Mike Aubry at 1/11/2001 12:22 AM EST
Engineer on team #47, Chiefs, from Pontiac Central and Delphi .
In Reply to: Can Anyone With a Field Help the Rest of Us?
Posted by aTm on 1/10/2001 11:50 PM EST:
We ahve 99% of the ramp and two goals built. Here are my observations.
- It is easier for a human demonstrating the strategy of pulling a goal up the ramp and balancing than for the robots that will be constructed to play this game
- The goals are alot heavier and difficult to manipulate that we initially thought they would be
- The ramp tips very easily and the balance point changes rapidly, therefore a robot that gets to the place on the ramp needed to initiate it tipping, will need to reverse direction and move a few inches the opposite way by the time the ramp gets to the level position in able to keep it from “going to far” and having to repeat the process because the ramp has “flipped over”
- Lifting a goal is easier if the robot could lean backwards so as to instantaneously move the combined cg of both it and the goal it is attempting to lift
- The coordinated effort of two or more robots make “doing stuff” easier - one pushes while one pulls, etc.
- Flipping goals and aligning them sideways or length ways to enable more big balls to be score on top of them, is alot easier said than done
- Going slow up the ramp, which does take some time, is needed to get the ramp to balance, but also going over the ramp in pairs will require more coordination than we initially thought. (Hint: once a robot passes over the balance point, be sure the other one does not accidently back up instead of go forward. Big bang theory and NOT a very soft landing is in store for one of them)
- Hope that helps, seeing the real stuff has enlightened us to what will or won’t be “EASY” to do. BUT, we now look forward to seeing just what we CAN do, and do well. Nothing like a little reality !
Posted by rebecca at 1/11/2001 12:29 AM EST
Student on team #192, gunn robotics team, from gunn high school.
In Reply to: Can Anyone With a Field Help the Rest of Us?
Posted by aTm on 1/10/2001 11:50 PM EST:
The goals are, for one thing, VERY heavy. We brought out our 'bot from last year and did some tests. one goal full of balls puts a lot of strain on our drivetrain (2 drill motors, tank style). As for picking up a goal…again, hard. They weigh around 50 pounds (this is an estimate)
We have not tried stacking yet put i do know one thing: while balancing with the goal upright, things can get tippy. a flexable but sturdy way to attatch to the tower is a good idea.
thats all i have right now…
: I realize that there is most likely a very small number of teams that already have that evil ramp built AND two accurate goals, but I know that there has to be at least one 2001 field already in existence out there. Or at least I hope so, because as I’m sure that most of you have now recognized, there are many strategies/designs/concepts/ideas/whatever that simply cannot be followed further OR thrown out simply because WE DO NOT KNOW! Example: how hard is it to push two goals back to back up the ramp? how hard is it to pick up the goal? can two goals be stacked somehow sideways on the ramp since they obviously cannot fit side-to-side. These are just a couple questions, and any general impressions of the field/goals/ramp that are completed would be GREATLY appreciated by I’m sure much of the forum. As for Wildstang, we will most likely have most of the field constructed within a matter of days, so I will gladly convey any impressions myself or the rest of my team comes up with once the field is completed. Thanks in advance to anyone that has experienced the 2001 field.
:
: aTm
Posted by Andy Baker at 1/11/2001 8:46 AM EST
Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.
In Reply to: Can Anyone With a Field Help the Rest of Us?
Posted by aTm on 1/10/2001 11:50 PM EST:
We have built one goal, and here is it’s weight.
Empty goal = 71.5 lbs.
Goal w/ 11 balls in it = 83.5 lbs.
Goal w/ 11 balls in it & 1 big ball on top = 88 lbs.
Andy B.
Posted by Lora Knepper at 1/11/2001 12:18 PM EST
Other on team #419, Rambots, from UMass Boston / Boston College High School and Seeking Sponsorship.
In Reply to: Weight of Goal
Posted by Andy Baker on 1/11/2001 8:46 AM EST:
Thanks for posting the stats Andy…that will prolly impact what we design…or at least be food for thought!
~ lora
: We have built one goal, and here is it’s weight.
: Empty goal = 71.5 lbs.
: Goal w/ 11 balls in it = 83.5 lbs.
: Goal w/ 11 balls in it & 1 big ball on top = 88 lbs.
: Andy B.
Posted by Rick Gibbs at 1/11/2001 11:11 PM EST
Engineer on team #145, T-Rx, from Norwich High School, Sherburne-Earlville High School and Procter & Gamble Pharmaceuticals.
In Reply to: Weight of Goal
Posted by Andy Baker on 1/11/2001 8:46 AM EST:
Thanks for the info. Any idea how high the center of gravity is?
Posted by Andy Baker at 1/12/2001 9:58 AM EST
Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.
In Reply to: Center of Gravity?
Posted by Rick Gibbs on 1/11/2001 11:11 PM EST:
I didn’t really have a good way to do this, but here’s what I did:
I placed the goal on it’s side, on top of two stacked 4x4 boards. I got the goal to balance on the boards. Then, I measured the distance from the bottom edge of the casters (where the floor would be) and the center of the balance point.
And that distance was 24".
Your mileage may vary.
Andy B.
Posted by Raul at 1/12/2001 10:18 AM EST
Engineer on team #111, Wildstang, from Rolling Meadows & Wheeling HS and Motorola.
In Reply to: Center of Gravity = 24"
Posted by Andy Baker on 1/12/2001 9:58 AM EST:
There is another way to find the CG;
Put the top end on a scale while the base sits on the floor - take a weight reading. Then put the base side on the scale and the top on the floor - take a reading.
If ‘x’ is the distance of the CG from the base,
‘L’ is the diatance from base to top,
‘T’ is weight (force) at top,
‘B’ is weight at base, then:
T(L-x) = Bx
So just solve for ‘x’ and you have it.
It will be even more accurate if you have two scales and can weight both end simultaneously and can keep the goal horizontally level (prope the scale up). This technique works for most long objetcs. Hope that helps.
Raul
: I didn’t really have a good way to do this, but here’s what I did:
: I placed the goal on it’s side, on top of two stacked 4x4 boards. I got the goal to balance on the boards. Then, I measured the distance from the bottom edge of the casters (where the floor would be) and the center of the balance point.
: And that distance was 24".
: Your mileage may vary.
: Andy B.
Posted by mike o’leary at 1/16/2001 10:09 AM EST
Student on team #419, rambots, from bc high.
In Reply to: Re: Center of Gravity = 24"
Posted by Raul on 1/12/2001 10:18 AM EST:
has anyone out there done rauls math? T(L-x) = Bx? anser would be interesting
mike oleary
There is another way to find the CG;
: Put the top end on a scale while the base sits on the floor - take a weight reading. Then put the base side on the scale and the top on the floor - take a reading.
: If ‘x’ is the distance of the CG from the base,
: ‘L’ is the diatance from base to top,
: ‘T’ is weight (force) at top,
: ‘B’ is weight at base, then:
: T(L-x) = Bx
: So just solve for ‘x’ and you have it.
: It will be even more accurate if you have two scales and can weight both end simultaneously and can keep the goal horizontally level (prope the scale up). This technique works for most long objetcs. Hope that helps.
: Raul
:
: : I didn’t really have a good way to do this, but here’s what I did:
: : I placed the goal on it’s side, on top of two stacked 4x4 boards. I got the goal to balance on the boards. Then, I measured the distance from the bottom edge of the casters (where the floor would be) and the center of the balance point.
: : And that distance was 24".
: : Your mileage may vary.
: : Andy B.