2023:Arm

*DISCLAIMER* The wiki wasn't operational for the first week or so of build season, so these entries begin from January 12th-ish and beyond.

Kickoff through 1/12/2023

There were lots and lots of concepts that were brought up during prototyping and our whole team design discussion. We did a weighted objectives table to determine which design was favorable based on a variety of criteria. A few of the different ideas that were thrown around were a 4 bar linkage arm, vertical elevator with horizontal elevator, as well as telescoping arm with a rear pivot. We also did some rough geometry sketches during this time, to further support our decisions and data from the weighted objectives table. After that was all said and done, we decided on a telescoping arm with rear pivot. This brings us up to now, 1/18/2023, which is where we have begun detailed design.

1/17-1/18/2023

We have begun detailed design. Here are some rough specs of the arm so far:

• 67-69 inch reach when fully extended
• Dual ball screw actuation for a strong and speedy pivot
• 4", 2.5", and 1" square tubes, with .125", .125" and .188" wall thicknesses respectively
• Have not decided method of actuating telescope just yet
• The posts that the telescope mount to are 20-22 inches tall.

1/18/2023 - Part 2: Continuing Detailed Design

We took our telescoping tubes with bearing blocks, and added all the bearing blocks we need. Now we have actual hard stops for each stage, and things are a little bit more solid. We reduced the bearing block thickness to 5/16" from 1/2" because this arm is not specced to bear 100+ lbs, but much rather the weight of the cone/cube + manipulator. As for the gripper to arm interaction, we are going to tap holes on the end of our Stage 3 tube, and allow the gripper team to do what they want within those holes. Off to the side are some screenshots of our current design fully extended and also the nesting and layout of our bearing blocks. They are color-coded so they're easy to see in CAD.