pic: FVC Team 228 at the 2006 ConnVex Event



After evaluating the 2006 Hanging-A-Round game, the members and mentors of Team 228 have come to the conclusion that unlike the 2005/06 Vex competition game where basically there was one design that worked well (the tank-tread elevators) and ended up winning, in the new 2006/07 game any number of radically different ideas (whether they are arms, elevators, tank-tread intakes, scissor-lifts, etc.) can all do just as well as one another.

From the diverse range of awesome robots at the 2006 ConnVex event, the teams who would win were the robots that could score as fast as possible; the actual mechanism on how they did so usually didn’t matter much. I saw single- and double-jointed arms, elevators, tank-tread intakes, scissor-lifts, and many more different ideas.

That being said, here is Team 228’s 2006/07 Vex competition robot as it appeared at the ConnVex (Connecticut Vex Championship) Tournament. In autonomous mode, our robot could score three softballs in the upper goal; in the entire match we usually averaged around 7-9 balls in an upper goal. There was only one other team at ConnVex who could outscore us scoring in the high goals, and that was Team 40.

Our robot holds a maximum of six balls simultaneously, and we could (and would often) score four at a time into the upper goal. Our drivetrain was fast and reliable, and overall the robot mechanically and programming wise was quite sound. We ended up in 9th place in the rankings, picked into the 3rd alliance, and competed until we lost in the semi-finals by 5 points.

More pictures, as well as some great video coverage, from the event will be online as quickly as possible at www.connvex.org. :smiley:

Excellent Robot from 228 I rate it (without knowing its performace) a solid 9 a couple questions though:

What gear ratio did you use in your drivetrain?
Could it climb the platform?
Did it only score in the high goal?
What kind of mechanism did you use to get the balls up to the goal(an elevator perhaps)?

And Possibly more questions to come…

-Dustin

it appears as though the wheels are 1:1 with a 4 motor drive. but i dont know. did you quallify for champs?

Team 228 was eliminated during the Semifinals against the alliance of 839, 2160, and 2013 (IIRC, 2013 were captains, but I missed alliance selection).

The finals were then 40, 2078, and 3197 (again, IIRC, 40 were captains) vs them, and the Team 40 alliance ended up winning in three matches.

Here is a picture of the rankings bracket. There were only 6 alliances, which is why you see gaps in the QF’s:
ImageShack - Best place for all of your image hosting and image sharing needs](ImageShack - n50782710998305651uk8.jpg)

As for championship eligibility, obviously the winning alliance qualified, but I do not remember who won the Inspire Award.

I’ll answer some technical questions here.

It is a direct drive, 4 motor drive train. We thought it would be a little too fast and difficult to control, but the speed definitely worked for us after a little practice. We were clicking off the clutches in some turns, but we’re not going to change it.

To tractor the balls off the ground, we used the small wheels to roll the balls around a curved backplate. Balls then rolled into an upper hopper, which could hold 4 balls. Two more balls could be held in the two independently driven rollers, for a total of 6. We would dump 4 at a time into the high goal, then re-load the other two balls and immediately re-dump.

The upper hopper is lifted with with 2 motors, and uses a continuous chain arrangement to power it up and down. We doubled up the chain to increase its strength. IFI’s linear slides are used to achieve the smooth movement.

Our ground clearance is 1.5", which easily gets us on to the platform. Though, we don’t hang (yet…) Our strategy is focused on scoring balls in the high goal and gaining control of the atlas ball.

Feel free to ask more questions. Hopefully, we’ll have more pictures up on our website soon.

BEN

Dude thats the most bad $@#$@#$@# idea ever with the balls pulled up by wheels:D

I appeciate your willingness to answer questions!
Looks like the largest size chassis kit?
What’s your motor count/use?
I see 4 on wheels (4") direct drive
2 as pair? for elevator,
1 for lower roller,
1 for upper roller?

What is the ball pickup mech, I see tank tread.
Looks like the small wheels used for ball roller have their tires inside out;
thats the first time I’ve seen that, did your team think it up or see it elsewhere?

What is the most activity done during Autonomous mode, just dump the preload, or any line-following or random driving? There is mention of scoring 3 balls in autonomous mode, but I thought the rules were no more than 2 balls per robot? Did you take a handoff from your partner?
Thanks, I’m looking forward to more details at the website.

I’d be more than happy to answer some more questions. It’s not quite the largest chassis size. It’s a 25x25, though we are exactly 18" high!

Motor count is at 8 right now.

  • 4 for the drive
  • 2 for the elevator
  • 1 each for the intake rollers (the kids found it was easier to position the stored balls with seperately powered rollers)

For the ball pickup, we use a couple different devices. The outboard intake roller is a single tank tread pulley with the tank tread wrapped around it. This wheel is mounted on a rear-mounted swing arm, and can move up and down to adjust to varying sized balls (or the stitching on the ball.) We use chain and sprockets to run this roller off the 1st impeller motor. It’s sped up, but not by much.

We then used the rubber 2.75" wheels, but turned the tread around so that we could, again, adjust for varying size balls. The curved walls that we walk the balls up are mounted at the top of their arc, and float on the bottom. We use the vex-legal elastic bands to pull the bottom of the arc, which keeps tension on the ball as it’s walked up the arc. We’ve seen systems similar to this on FRC robots, but obviously nothing on a FVC bot.

Our Auto-mode is still being tweaked, as we weren’t totally happy with it. Yes, you can only start with two balls, which we load in our hopper. We elevate the hopper and dump the balls in about 2 seconds. We then lower the hopper, drive forward and pick up one more ball from the pile in front of us. While the balls works its way up the intake wheels, we back up to the goal. Once the ball is in the hopper, we elevate and dump the 3rd ball. At the moment, it’s all done by timing loops, which we had to tweak over and over to get it right. For our next comp, we’ll probably have encoders and bit more tweaking done.

However, the three balls in Auto wasn’t even close to what Team 40 was putting up. I’ll let them post their auto-mode (and robot description) if they’d like. They’re the main reason we want to improve our auto-mode. :slight_smile:

I’m waiting for the pictures too! Keep an eye out on the Connvex.org website as well. There should be some pics there soon. Hope this helps,

BEN

Your wish has been granted. “Poof”

http://www.checkmate40.com/Video/Connvex06/

Can you give us a description of how your robot is actuated. I get the jist of the mechanisms from the videos, but can’t tell exactly how you did it.

The kids used tank treads as chains (stronger) and fixed a link of tred to the basket.
The rest works the same as the tank tread would on the floor. Except with
a fixed anchor point, when the chain spins it lifts the basket. 2 motors
provide the power to get the job done and a little extra in case they want to
lift something heavy in the future.

Lots of photos posted at http://www.connvex.org/?page=gallery with more to come!

How many balls can it hold? What was the average amount of balls other teams could pick up?

We can hold 7-8 balls pretty easy, we can hold 2-3 in the intake and 5-6 in the top hopper.

To me the avarage was about 2 balls.

Sorry to hi-jack your thread Art :frowning: If you would like
I can create a new thread.

Sooooooooo Cooool. :] :slight_smile: :]