Bumper Mounts Overview
We first started building these bumpers at the start of the 2024 off-season with out first proto-type. Over the 2025 season and into the future we will continue to update our design for faster and easy bumper changes. I would heavily recommend reading the entire document as important information is provided throughout. This document is highly open to change, submit your ideas on how to improve on the cheifdelphi thread: (Link)
Benefits of our bumpers: - Easy to print parts - Reliable through the season+ - Simple and applicable mount design to most bots.
Bumper specifications: (Note: Frame size and measurements for bolt holes will change based on bot frame size. In this situation the bot frame size was 29", Both bumper mounts were made out of aluminum and have not been tested out of 3D printed material. Bumper plungers however were made from Markforged-Onyx filament. 1 out of 16 bumper plungers broke through the season and into offseason due to heavy usage. The files listed in this document are updated with thicker walls but have not been tested. If you are thinking of printing these parts, I would highly advise using 100% infill, filament upwards or PETG as well as printing backups in case of failures). We used a wooden 30-3/8" inside width frame with 3/4" thick plywood. On the frame we spaced 1/4" holes which were 9-5/8" horizontally by 4-1/4" vertically from the inside frame. This allowed us to put round headed 1/4-20, 3.5" long through bolts (https://www.mcmaster.com/90185A414/) to align with the bumper mounts we machined. We added the plungers and bumper mounts with holes to where they wouldn't interfere with our moving systems so that the bumpers can't move when plungers are locked into the bumper mount holes. 1.125", 0.36" OD, 0.308" ID Springs (https://www.mcmaster.com/9434K71/) would lock plungers in place to prevent plungers from unlocking from the bumper mounts.
ONSHAPE BUMPER MODEL: https://cad.onshape.com/documents/a2bea0b59e4cda41c4f4343d/w/40b435d8f7ad6e2bcfac27c0/e/c8ce16ce459608bc8ce1510d?renderMode=0&uiState=691a453f9fd4452b56692848
Individual STEP, STL and ONSHAPE files are listed in following pages ↘
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