VEX Drive Trains 2007
 

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! :D

Re: VEX Drive Trains 2007
 

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.

Re: VEX Drive Trains 2007
 

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

Re: VEX Drive Trains 2007
 

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!

Re: VEX Drive Trains 2007
 

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

Re: VEX Drive Trains 2007
 

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.

Re: VEX Drive Trains 2007
 

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.

Re: VEX Drive Trains 2007
 

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.

Re: VEX Drive Trains 2007
 

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

Re: VEX Drive Trains 2007
 

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

Re: VEX Drive Trains 2007
 

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... :yikes:

Re: VEX Drive Trains 2007
 

60 tooth, alternating gear/wheel

Re: VEX Drive Trains 2007
 

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

Re: VEX Drive Trains 2007
 

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

Re: VEX Drive Trains 2007
 

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

Re: VEX Drive Trains 2007
 

Posts or side goals? It is illegal to descore the rings on the posts... unfortunately :p

Re: VEX Drive Trains 2007
 

You can also de-score the platforms. However I don't think de-scoring will be a big thing at the regional events. I haven't seen any strategies really using the low goals or the platform for scoring. If the robots can't score on the posts they go to get the goals.

Re: VEX Drive Trains 2007
 

More Robotics participates in a local VEX tournament in the fall to prepare for FRC. The game was to pick marbles out of a pit in the middle, and fill up teeter totters. Our team decided to use an Omni drive so we could be very manuverable. The Omni drive worked very well for what we needed.

Re: VEX Drive Trains 2007
 

My team is using a 4 wheel design (but that will be changing very soon ;)) with chain. It has a two speed transmission, similar to the one we used in last years FVC competition with a small change.

This is the test bot we made over the summer

Thats a little dated, but the transmission is no different.

Best of luck to all FTC teams!

Regards,
Team Unlimited (FTC #1) and its members

Re: VEX Drive Trains 2007
 

We can schlerp rings off the movable goal platforms and drop them outside the field, (as well as push them out of the side goals), but it's unlikely that we would do so. In a tight match, we can score as quickly as de-score, and you get more rank points by playing offensive than defensive. In an unbalanced match, it might even be worthwhile to score some points for the other team (or at least let them have the movable goals).

Re: VEX Drive Trains 2007
 

Silly RP

Re: VEX Drive Trains 2007
 

We're using 6WD with 4 1:1 all purpose wheels, and 2 front large omniwheels. I'll put up pics as soon as I can.

Re: VEX Drive Trains 2007
 

team 93 is using a 6WD with 4 inch wheels, the two back ones are powerd with a 60-36 gear ration and unpowered large omnis in the front... we will probably be working on a more complex one for our next regional;)

Re: VEX Drive Trains 2007
 

Team 85 had 8wd with shaftdrive and 2 omnis in the front. It was all the small wheels.