VEX Drive Trains 2007

[Akash Rastogi]

Just curious as to how teams are making their drive trains this year. Post gear ratios, wheel size, chain/gear driven, other opinions. Attatch pictures of the drive train as we need a little help for new drive train ideas. Also feel free to post up your own questions. Thanks in advance! Post up your end effectors if you wish also. Hope everyone is having a great season!

[Cartwright]

We have a six wheel drive system, that has a rock in it for maneuverability. We are driving each side with two motors and we're using medium and small gears. We thought about chain, but it's just not sturdy enough for us.


Sorry...no pics.

[Andrew Bates]

4 motor 4 wheel 36:12 gear ratio using two large wheels and two medium omni wheels.

[TheOtherGuy]

546 had a 12 wheel 6 motor drive train this year using small wheels and a gear tooth ratio of 36:12. The four end wheels were raised for a better turning radius... the only problem was power! (and axles sliding out of clutches due to untightened lock collars) I think we have a picture somewhere...

Here it is!

[basicxman]

2 module crab drive, small wheels then 2 small wheels without tires for casters, actually works pretty well

[Phyrxes]

Team 183 is also a 6 wheel bot, it rocks as well for maneuverability but we elected to only drive 4 of the wheels and make the other two "free wheeling" omnis.

[Akash Rastogi]

Originally Posted by Cartwright

We have a six wheel drive system, that has a rock in it for maneuverability. We are driving each side with two motors and we're using medium and small gears. We thought about chain, but it's just not sturdy enough for us.


Sorry...no pics.

Yea, we tested with chains a few times in different orientations but it just wasn't strong enough. Right now our robot pushes around 30 lbs on carpet with hardly any weight on the robot itself. Also, we've been looking at 2 speed transmissions b/c we have the power but we definitely need more speed for this game. And we began focusing on the end effector.

[rswsmay]

Our team has not yet fully decided on a design yet. We are considering various design concepts and are working toward prototyping each one before selecting a final design. We have decided on a multi-speed drive train which we have already built and tested. We are also prototyping an ackerman steering system which we hope will improve drivetrain performance during turning manuvers. We completed some preliminary calculations, worked out the geometry and built 2 prototypes this past weekend. In conjunction with this, we plan to develop a software program to drive the wheels on both sides of the robot (actually all 4 wheels independantly) at the necessary speed to minimize skidding/dragging.

We are also toying with developing a 4 wheel steering system, but have not worked on any of the mechanics for that yet.

[fredliu168]

6 wheel all-purpose wheel gear drive. 1:1 gear ratios on the drive.

[Akash Rastogi]

Originally Posted by fredliu168

6 wheel all-purpose wheel gear drive. 1:1 gear ratios on the drive.

Currently working on that but with 4 wheels. Which tooth gears did you use though?

[alex1699]

i not in vex I'm in FRC and i just so happen to have a vex robot i just figured out how to do swivel drive with one wheel and two omni wheels so now I'm going for two swivels and then the next project will be 4 swivel wheels...

[fredliu168]

Originally Posted by XxMORTteam11xX

Currently working on that but with 4 wheels. Which tooth gears did you use though?

60 tooth, alternating gear/wheel

[shsroboticsclub]

Two speed transmission with a special type of steering, I wont say just yet. oh and four wheels.

[Akash Rastogi]

Anyone plan on de-scoring? Or is anyone already capable of doing so?

[basicxman]

Originally Posted by basicxman

2 module crab drive, small wheels then 2 small wheels without tires for casters, actually works pretty well

correction to my teams drivetrain
6WD!!!! way better than swerve, it turns out the my autonomous sucked with the swerve (you know how the motors always 'twich' when you turn on the robot) well that screwed it up pretty bad