What wheels is your team using???
 

My team is messing around with different wheels, trying to maximize traction while still being able to turn and be agile. We have determined that all wheel drive plaction wheels givesall the traction in the world but no turning ability. We are wondering if we are just using the wrong drive system (4 Wheel Drive), or if it is just an incorrect choice of wheel (Rough Plaction). If anyone has opinions or suggestions we would appreciate it.

Thanks,
Team 2549

Re: What wheels is your team using???
 

bump

Re: What wheels is your team using???
 

mecanum wheels. we made our wheels for our robot.

Re: What wheels is your team using???
 

You may be able to find something here to help you out....
http://www.chiefdelphi.com/media/papers/1443

Re: What wheels is your team using???
 

4 wheel drive depending on the layout (long and narrow) with high traction wheels will definitely not turn well at all. A wide layout 4wd should turn fine.

We are using 8wd with dropped center wheels with colson performa wheels.

Re: What wheels is your team using???
 

You might find this white paper helpful. http://www.chiefdelphi.com/media/papers/1917

Understanding why some robots turn and others don't is a big part of making a successful drive train, and I've blogged a bit about it for my students here http://botshop.wordpress.com/page/2/

We're using an 8 wheel drive system, with the axles evenly spaced about 10.5" apart. We are using 6" IFI (VEXPro) Traction wheels with 1.5" wide roughtop tread on the middle two axles, and 6" AM "kitbot" wheels from 2007 and 2008 on the ends. The end axles are raised 1/4", so the end wheels don't contact the ground when we are on the flat.

The wheels are driven directly off the output shaft (we have the extended output shaft) of a 14.88:1 toughbox.

The performance is astounding. It outperforms EVERY drivetrain we've built, inlcuding a mecanum drive. I figure we can go from full speed to stop, turn 90 degrees and get back up to full speed in about the same time it took the mecanum to come to a stop and begin to strafe sideways.

Admittedly, the mecanum had a higher top speed, (12.75:1 driving 8" wheels) but it rarely reached it, and we do have a bit more weight to add to this machine, so the accelleration may drop off a wee bit.

This is our seventh year of building robots and we keep getting better at it, it seems, and I'm pretty sure after looking at what some other teams have built this year we can do better still. So good luck figuring out your drive and using that knowledge to form the starting point for your next 'bot.

Jason

Re: What wheels is your team using???
 

So far this year, we've gone with just 4 KOP "sticky" wheels. Now that today we got the robot actually working and driving around, kicking and not-quite-lifting, we realized 4 sticky wheels isn't going to cut it, with too much traction impeding our ability to turn (something I brought up way early in the season, but no one had cared).

Right now the plan is that Monday we'll replace two of them with "slick" wheels (the thought process is that they'll be front-left and back-right, or whichever two diagonal corners were the heaviest). I think that will make it drive awesome.

Re: What wheels is your team using???
 

We've got two 6" IFI wheels, 1 1/2" traction on the front, and 2 of the KOP slick wheels for the rear. All are powered off 2 KOP toughboxes, each with two CIMS geared together.

Re: What wheels is your team using???
 

Front-roughtop
rear-slick
...same on the other side

Re: What wheels is your team using???
 

6" plactions in the front, dual 6" plastic omni's in the back. it goes over the bump both ways no problem (fits under the tunnel too).

Re: What wheels is your team using???
 

6 wheel system with 2 omni wheels and 4 placton wheels on a pivoting drivetrain
http://www.youtube.com/watch?v=uRstQWId13k
http://www.youtube.com/watch?v=f6QmRkbvx-k

Re: What wheels is your team using???
 

4 plaction wheels.

Re: What wheels is your team using???
 

See attached photo. 4 of these on individual gearboxes...but these took 4 weeks to design and fabricate in total. It's too bad the bumpers and struts hide all of it. Oh, and we've had to re-machine the center hub since this photo...so there is some shiny silvery aluminum showing on the ends of the sprockets. The metal was hitting concrete on occasion with the design in the picture. Nothing like taking it all apart and putting it back together for team unity and morale.