Minibot pulling away from pole

[Sb28000]

Early on, we settled on a three-wheeled design, set at 120 degree angles to each other. However, we discovered (a bit late) that the third wheel, built on a pivot, would not maintain enough tension on the pole. Trying to come up with a new design, we thought of using basically trapping the pole between a length of Ttrix C-channel and the two powered wheels (that were parrallel to this bar). However, the minibot tended to pull away from the pole in the direction of the motors, and even with magnets we could not correct for this. We have since built something similar to Team 166's design, http://www.youtube.com/watch?v=ERVuEe9yytM
using four wheels, with two wheels driven from each motor. But we are still strugggling witht the minibot pulling away from the pole, backwards. If anyone could tell us if they encountered this problem or how they overcame it, we would appreciate it.

Team 2656

[Brandtlamonte]

Try and post a picture. All I can say is, limit the weight going away from the pole, use stronger magnets, etc. I'd show you mine, but my team doesn't want our idea stolen

[Sb28000]

Our minibot is curently in our shop, waiting to be taken along to our regional tomorrow. Right not there is nothing balancing the weight of the motors, and by applying a small amount of pressure by hand, it seems to climb fine. However, sincce our current design only holds the pole between its wheels and not latch around it, we are unsure how we could place the battery to properly balance it.

[Brandtlamonte]

Balance it at the bottom (assuming your minibot is the same as ours) to tension the wheels against the pole, or on the outside edge. If that doesnt work, try a different spot. Are you using magnets? Our team used magnets and we were slipping, added more magnets - no slip

[Sb28000]

Our current minibot does not have magnets attached; however, we previously had tried to use them. Currently, we were using a Tetrix axle at the bottom to allow the wheels to remain parallel to the pole, but it still continued to pull away. Thank you, we will try to put on some magnets tomorrow during the practice matches when we have time.

[Matt704]

Originally Posted by Sb28000

Our current minibot does not have magnets attached; however, we previously had tried to use them. Currently, we were using a Tetrix axle at the bottom to allow the wheels to remain parallel to the pole, but it still continued to pull away.

Your axle may not be positioned in the right place. It probably needs to be lined up closer to the middle of the wheels.

Here is what we did originally. Hopefully you can see it, but since it is on facebook you may have to be friends our mentor who posted it to be able to see it.
http://www.facebook.com/video/video.php?v=1775071903972

[IKE]

Keep tramming in the lower axle. It has a ton to do with efficiency and keeping the minibot on the pole. A little off will cause a lot of scrub and may cause it to eject itself.

Our architecture is derivative of the 166 youtube style bot. We literally built about 10 versions of it until we were satisfied enough for Kettering.