FRC/VEX Challenge

[Rick TYler]

With so many FRC people buying VEX kits now that they are on sale, I got to thinking about what to do with a VEX robot.

So, I went out and bought five 4-inch mini Poof balls. John, David and I are going to build a couple of quarter-scale Aim High robots shooting mini-Poofs. Just for fun. We'll post pictures and video links when we get it working. Is anyone else interested in trying this?

[LightWaves1636]

our teacher bought a kit too and we were thinking of a similar idea

[Ben Piecuch]

If you're building a 1/4 scale, I don't think a 4" poof ball is going to be the right size. 7"/4" >> 1/4... The raquet balls used in this years' VEX game are pretty good for a 1/3 scale game, as the balls are 2 1/4" in diameter.

Team 40 did just exactly this, and demo'd some of their robots at the BAE and UTC regionals. They had probably 6 or 7 different designs, including omni-drives, tread drives, swerve, etc... For balls, they found some of those "stress relief" balls that you squeeze to relieve, well, stress. They're about the same size as the raquet ball, but have the same "squishiness" factor as the poof balls. It was a VERY nice setup, and I'm hoping that we can build a copy of our '06 robot with VEX, just like we did with our '05 robot.

I'm a huge fan of VEX, and I think that it's participation can rival FRC in just a couple of years. The matches are as exciting, the quality of the robots are on par with FRC, and the kids can truly build 100% of it. If the low cost doesn't grab your attention, they could you please pass some of that extra cash our way?

BTW, there's a whitepaper somewhere here, showing the advantages of using VEX for prototyping and demonstrations. I think it fits very nicely with where I hope this thread will go.

VEX Whitepaper

BEN

[Donut]

I have that idea as well, my Dad and I came up with it when my brother asked me if we could have some robot he could bring in for school in 2 weeks. I'll put some pictures up as well when I have them.

[KathieK]

Originally Posted by Ben Piecuch

BTW, there's a whitepaper somewhere here, showing the advantages of using VEX for prototyping and demonstrations. I think it fits very nicely with where I hope this thread will go. (I'll try to find it and post the link)

BEN

Also note that there will be presentations at the 2006 FIRST Robotics Conference in April in Atlanta:
Using Vex to Supercharge Your FRC Team - Dan Larochelle & Donn Griffith and
Simplified Programming using easyC and WPILib for FRC and FVC - Dan Larochelle & Brad Miller

[gren737]

More information on Team 40's Mini FRC can be found in this thread:
http://www.chiefdelphi.com/forums/sh...222#post472222

[irishninja]

I'm going to try after I play more with the VEX. They should definatley have VEX competitions of the FRC game. I noticed thaat FIRST used the 2004 game as the VEX competition last year. It was cool to see similar designs. First I want to experiment with the rest of the kit though before trying.

[Rick TYler]

Originally Posted by Ben Piecuch

If you're building a 1/4 scale, I don't think a 4" poof ball is going to be the right size. 7"/4" >> 1/4... The raquet balls used in this years' VEX game are pretty good for a 1/3 scale game, as the balls are 2 1/4" in diameter.

Racquet balls -- check. Thanks for the idea.

Using 4" mini-Poofs in place of 7" balls isn't as silly as it sounds on the surface. The diameter is, as you say, not 4:1, but it's not just a matter of diameter. The volume of a sphere is 4/3piR^3. To find the ratio of volume, X: X(4/3pi2^3)=(4/3pi3.5^3), or 8X=42.875, or a ratio of roughly 5:1. So, the size is too big, but the weight is not. The balls are a little unwieldy for the average VEX-size robot, but the weight isn't bad. There won't be any 25-ball hoppers in this virtual challenge... I don't think.

[gren737]

We used these https://www.centurynovelty.com/detail_309_163-018.html
in our Mini FRC competition. They are exactly 1/3 the size of poof balls, but much lighter. However their density and "squishiness" factor was very close to the poof balls.

[skimoose]

Team 40's mini Aim High Vex game actually used 2.5" foam "stress" balls. Similar to these balls. There mass is much closer to the mass of a poof ball.

Racquetballs are rather heavy, we couldn't make a decent shooter with the vex motors, but add an old Victor 883 and an old 6V. FP motor and you've got a nice racquetball shooter.

[Donut]

Does anyone know what kind of stores would carry the 2.5" size stress balls? We've looked a few places and the closest thing we've been able to find is squishy tennis balls, which are still about twice as heavy as the one stress ball we currently have.

Our mini-robot for this year's game is very near completion; we need to drill and attach 2 more plates, then program it and do a final test, but it is otherwise finished right now.

[skimoose]

These stress balls are used as promotional give-aways by companies. You can find them online or at a business that specializes in promotional products for business. Online just google "stress ball".

[gren737]

look 3 posts up, i gave the link of the ones we used, they ship very quickly too!

i wasn't really able to find any in stores cuz it's kind of a weird hit or miss type thing.

[Jay Trzaskos]

I actually designed a game using the 4 inch poof balls that was similar to Zone Zeal for our Junior High kids to play. That reminds me, I have yet to build my bot for it...

[irishninja]

My friend and I attempted to build a flywheel out of VEX parts to shoot ping pong balls but it didn't work too well. We had the gear kit, we went from the biggest possible gear to the smallest possible gear and that was connected to a medium gear connected to a small gear. Basically we were trying to attain as much speed as possible but it only was able to shoot a pingpong ball like a foot. Anyone have any ideas?