Testing Materials

Tags: engineering, control, tips, innovate, think, and design
Personhours: 3
Testing Materials By Austin, Evan, and and Tycho

Task: Test Materials for V2 Gripper

Though our current gripper is working sufficiently, there are some issues we would like to improve in our second version. The mounting system is unstable and easily comes out of alignment because the rev rail keeps bending. Another issue we've encountered is the cervo pulling the grippers so that they begin to cave inwards, releasing any blocks being held at the bottom. By far the biggest problem is our intake. Our drivers have to align the robot with the block so precisely to be able to stack it that it eats a majority of our game time. However, there are some advantages, such as light weight and adjustability, to this gripper that we would like to carry over into the second version.

    We tested out a few different materials:
  • Silicone Baking Mats - The mats were a very neutral option because they didn't have any huge advantages or disadvantages (other than not adhering well). These could have been used, however, there were other better options.
  • Shelf Liner - It was far too slippery. Also, when thinking about actually making the grippers, there was no good way to put it on the grippers. Using this materials would have been too much work with little gain.
  • Baking Pan Lining (picked) - It was made out of durable rubber but was still very malleable which is a big advantage. We need the grippers to compress and 'grip' the block without causing any damage.
  • Rubber Bands on Wheels - This material was closest to our original version and, unexpectedly, carried over one of the problems. It still requires very specific orientations to pick up blocks, which would defeat the purpose of this entire task.

The purpose of this is as a part of our future grabber design, which will need to be relatively light, as our string is currently breaking under stress due to weight. The material must also have good direct shear and direct strength, as the grabber will have rotating arms that move in and out to grasp blocks. As well, we're replacing the tetrix parts with REV, as they're smaller and a little lighter, with the additional bonus of more mounting points.

Written on September 30, 2017