156B Week 6

Progress Since Week 5

Hardware

• Set up Greenhouse

• Cut out gridding for accuracy testing

  • Must measure/label

• Switched four of the corner brackets from plastic to aluminum parts

  • Stability of horizontal extrusions

  • In order to use the plastic brackets for the new swivel pulleys

• New Swivel Pulleys

  • Hanging upside down

  • Less lateral freedom of movement (less side to side)

  • Less rotational friction - smoother glide with cable movement

  • Wider sheave so we don’t have to replace cables

• Three more pulleys are coming in tomorrow

• Hole sawed and drilled into wooden UTM plate

Hardware Plans for Next week

• Implement 3 more pulleys

• Continuing implementing UTM mounting

  • Valve for hose

  • Vacuum

    • L Bracket

• Design station for End Effector holder

• Be ready for testing by Saturday

  • Iteration of code

• Still need to find locations to mount the tool head box

  • Define the coordinates and test the FarmBot picking it up

  • Design horizontal platform for this

CAD

• Performed FEA on entire system assembly using plastic corner brackets

CAD - Goals for next week

• Bracket replacement for full scale assembly

• CAD the UTM plate

Software

• Updated code from 3 to 4 motors

  • Speed, acceleration, boundaries

• Went through all the files in the source code to ensure everything is compatible with four motors instead of three

• Right now, G00 handler is written

  • Straight line movement point to point

• G28 handler - homing

  • Working on implementation

• FarmBot Commands

  • Picking up new toolhead

• All motors move concurrently

  • Movement is still two part

Overall Deliverables

• Show that UTM can be powered

• Lock down the accuracy of positioning

Materials Purchased this week

• New Swivel Pulleys

• Smaller diameter cables

• Hole saws

• Waiting on order from FarmBot

Materials to Buy (decreasing priority)

1. Retractable cable management device

2. Various types of seeds

3. Concrete/cement

Current Concerns (decreasing priority)

• None at the moment about movement

• None at the moment about hardware constraints and obstacles

• No updates on cable management

  • Sponsor is more concerned about positioning than cable management

Feedback from Meeting with Instructor

• Address friction in pulley and cable through sheave

  • Deeper groove so that the cable does not slip out

  • Wider diameter of the sheave

• Address excessive rotational freedom

  • Find swivel pulley that is limited in the side to side/front to back rotation and only rotates about vertical axis

• Next time for visuals, make sure the pulley and the spool are in frame and not cut off at the top

• Regarding watering

  • Cable management - how will water hose be suspended above UTM plate?

  • How will the force of the water affect tension in the cables and positioning?

Feedback from Meeting with Sponsor

• We hit the milestone Nick set for us last week - good job team 👍

• For future videos, find a point where we can record such that we don’t have to move the camera or scan the camera to focus on individual parts

• When working with cement, use proper PPE (face coverings)

• Really excited about all the progress we’ve made

• We brought up a lot of challenges that he hadn’t thought of

Upcoming Goals

Weeks 6-8

• Create spools with general wood components

• Test positioning accuracy with 4 stepper motors and current code

  • Construction tape or mesh for grid

  • Continue testing and reiterating code

• Address the issues seen in Proof of Concept

• Work to convert FarmBot code from interpreting Cartesian coordinates to barycentric coordinates

• Assemble UTM and cables to plate

Weeks 9-10

• Motorize end effectors for functionality

• Electronic Cable management (tentative - pending progress on positional accuracy testing)

  • Find and attach device to neatly manage power cables for the vacuum and camera upon UTM

  • Tensioned Cable Reel or similar solution

• CAD of custom parts and documentation

• Ensure that component level designs work before we begin and finalize documentation

Budget Remaining: $1787.15