pic: Jester Drive:Mecanum Wheel Drive Train

[Jeffmudhs]

Originally Posted by RBrandy

That whole system looks very heavy... Is it?

Where do get wheels like that?

The robot when completed, with arm, without any lexan protection was around 86 lbs. The wheels, wheel molds, were created by team members under the assistance of mentor Mr. Crane (aka mold master). They are omni directional, www.airtrax.com has a great video of the wheels in use. Mr. Crane talked to the people in airtrax to get what was needed for the molds. Our first molds were made of a nice blue clay, that wasn't very symetric, we then moved to a silicon mold. We will have a display in the pits if you see us in drexel or nationals. If your in pittsburgh now, you should stop by.

[edit] To see the airtrax video: click on the link provided, click on the picture labeled sidewinder, then click on video

[Ken Delaney 357]

The wheels will allow us to drive omni-directionally. Right now we drive forward/ reverse and sideways. Here is video of us driving sideways. http://www.first.udsd.k12.pa.us/AIA2005/video.html We can also spin inside our own footprint. The design makes us very agile. With more programming time and a custom circuit we hope to drive omin-directionally with accuracy. Our initial controls had too much drift in it.

[thoughtful]

WOW, looks awesome.

This is something new to me, kodos to your team on buildign such an innovative and manuverable robot.

[663.keith]

I think WPI had wheels similar to these on their robot this year. I'll try and find a good picture of them.

[roboticscom13]

These wheels are similar but very different to the "grenade" wheels. These wheels are specifically designed for the purpose of allowing slip so the the robot can move laterally left and right as well as provide decent traction for forward and backward movement. However i do not believe, from what i have read on the"grenade" wheels, that they allow for this type of movement. To the best of my knowledge the grenade wheel is just another way to create an omni-wheel, but please correct me if i am wrong. The total weight of the entire robot is 105 lbs. In fact that is with no "speed" holes at all.

[ahecht]

Originally Posted by 663.keith

I think WPI had wheels similar to these on their robot this year. I'll try and find a good picture of them.

I'm glad we weren't the only ones crazy enough to try something like this. Out of curiosity, how do you guys control the robot?

[roboticscom13]

I stand corrected. Yes we do control the robot.

[ahecht]

Originally Posted by roboticscom13

I stand corrected. Yes we do control the robot.

Oops, major typo there. I meant "how do you control the robot", but I left a word out. Are you using one joystick for translation and another for rotation, modified tank steering, or another method?

[rocknthehawk]

i'm assuming team 190 has pretty much the same wheels, and when i saw them at BAe, my jaw hit the floor...they are AWESOME. My only question is, do htey make it easier to push around? also, i noticed team 190 had some trouble controlling it early on...how exactly DO you control it??

[ahecht]

Because of the orientation of the rollers, a mecanum wheelbase is never in a position where it can be pushed without skidding. In the worst case scenerio, where the robot is pushed on a diagonal, there are still two wheels with rollers whose axes are aligned parallel to the pushing force. I can't speak for the Jesters, but if their rollers are anything like ours, they have pretty good traction and pushing resistance.

On 190, we have our controls set up with a one stick to translate the robot and a second stick to control rotation. I know that they were having trouble getting everything working at BAE, but the system worked pretty well in the shop.

[Jeffmudhs]

We use one controller. If I remember correctly, mind you i'm not on the drive team and have not driven the robot, i believe we use the trigger + direction for translational drive, and the button to spin. As stated above, We are not easily pushed because of the orientation of the wheels. they form to make a shape such as:

\ /
/ \

It is noticable on the drawing above. The wheels allow for slip so we can be pushed with enough force and so that it does not damage parts for the drive train (easily, all things break).

I hope this answers your question.

[SizzelChest330]

Do you guys know how much actual Pushing power you have? I know with Mecanum wheels you need alot of traction or else you wont get very far in a pushing match...
And do you know your speed with them?
I'm guessing with 4 wheel CIM Motor drive your getting about 6-8 Fps or am I wrong?

[Nitroxextreme]

those wheels look so awesome
all they all custom made by your team

has anyone been able to find a place to buy them
i know that my team wanted to use them what was unable to find them for purchase

and without a decent shop we have almost no choice but to not use them

[Jeffmudhs]

As stated previously, yes they were all created by the team. Hand mixed, and hand poured. That includes the molds we have used to pour them into.

[CyberWolf_22]

My team and I have had a design using these wheels for the past two years now but have not found a way to produce them. It is great to see that a couple teams have done it successfully. Good Luck at your regionals. I will be sure to stop by your pit at championship.