Bumper Mounts and Lifter Bars
Our combined solution for mounting our bumpers and lifting the robot has worked well for us in 2022 and 2023. Here’s what we use and why we settled on this design.
Constraints
Bumper Mounting Constraints
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The mounts need to be secure.
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The bumpers need to be fairly easy to align on the mounts.
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Whatever fastener is used to secure the bumpers needs to be accessible from the top, even if most of the frame rail is obscured.
Lifting Constraints
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The robot needs to be liftable by two people without needing to keep hands under the bumpers.
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The robot needs to be safe to lift from a ~3 foot height to the ground, where the robot may not be level (this requirement came from 2022)
Solution
Mounting
Especially when we used swerve modules in 2023, the corners of the robot frame became clear real estate for bumper mounting. Therefore, we used eye bolts to attach our bumpers.
Nothing particularly fancy here, just a bolt and a washer. These screw into threaded spacers mounted to the frame corners. The length of the acetal spacer (black) determines the bumper height. We made our bumpers higher for 2023 than 2022 (over-bumper intakes vs charge station clearance) and the only major change was lengthening these spacers. Note that the tube is bowing a little bit, which is not great, but it did hold up.
The two washers capture the corner brackets on the bumpers:
The bolts are tightened finger-tight, though a screw hook or similar shape could be put in a drill to make the process faster.
Lifting
With eye bolts at all four corners, we can attach our lifting bars:
These bars are fairly self-explanatory from the picture. We used the rounded-corner box tube supplied in the 2020 KoP to simulate the bars under the climb structure. The rounded corners make the bars a little more comfortable to hold. By the end of our first 2022 event, the lifting bars also became a way to display stickers we collected from other teams at our events, acting as a bit of team history. We attach the bars to the eyebolts on the robot with carabiner clips, then we can just unclip the lifting bars and leave the field.
Final Notes
Our bumper mounting solution is something that’s approachable for many teams to create with a handful of hardware-store parts and some tube stock. However, due to the geometry of the MK4i modules we plan to use next year, we won’t have the tubing corners to mount the bolts on. Our CAD team has been designing some modified approaches, but we don’t know what we’ll actually end up doing for next year’s robot.