Bumper height and interaction with charge station

My team (5438) is currently mounting our bumpers to the robot (kitbot), and we are wondering what height to mount them at. We want to mount them as low as we can reasonably do so (to avoid running over game pieces and for being favored in defense), but we want to be sure that they interact well with the charge station. However, we do not have a charge station prototype to test this with.

So, for teams that have charge station prototypes, what bumper heights have you found to work well?

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Our testing is somewhat limited and we are still working out our bumper height ourselves. but we noticed with our previous year’s robot that having bumpers mounted vertically centered in relation to the kit chassis caused some issues with getting on the plywood variant of the charging station.

One thing we needed to keep in mind with this is that at the time, we didnt have polycarb sheets installed on the “flaps” of the charging station so it did not form a proper wedge with the ground. this gave the station a large lip that the bumper and robot needed to get over. Note that this robot and its bumpers had no issues traversing field cable covers but struggled on that lip. With polycarb sheets installed our new drive base was able to get on no problem; however we have not tested with bumpers so take that info for what it is.

I don’t think the kit bot will have many issues with the charge station. However, make sure you follow the bumper rules and make sure they are below 7.5" from the ground. In general, the higher the bumper, the better it will be to “slide” along the bumper until the first wheel hits the slope.

In addition to bumper height, another important thing to think about is the fabric that you use on your bumpers. There is a large range of fabrics that you can use, and some are going to be a lot stickier than others.

Has anyone tried using the brushes from 2019, Destination: Deep Space, on the inside bottom of the robot to keep game pieces, like the Cube, from sneaking under their robot?

In Destination: Deep Space, the Bill of Materials for the Team Elements (plywood version of the Field Elements) included a brush material. It was used to hold the Hatch Panels in place until a Robot could positively remove it to be placed on the field.

A few weeks ago I had the crazy idea of using something like this to help brush materials forward of the robot since the bumpers will need to be high enough to clear the initial 35 degree angle of the Charge Station. They could even be used to define the Frame Perimeter if they are mounted between the robot structure and the bumpers. This would aid any robots who are merely herding Game Pieces between the Loading Zone and the Community.

From the blue box from R410:

Flexible ROBOT elements, such as thin plastic, do not accomplish this intent and are not considered “structure/frame” of the ROBOT.

As such, I would not plan to use door sweep plastic as part of the frame perimeter without a good Q&A support. Actually, I wouldn’t anyway, because the bristles are quite likely to stick out beyond the frame perimeter.

1296 has a PC covered charge station, and we’ve tested our robot/bumpers on it. We are using a 2 inch ground clearance on our belly pan, and the bumpers are mounted flush with the bottom. We are also using the USA Twill sail cloth for the covers. This configuration goes easily up the charge station at any speed.