156B Week 4

Progress Since Week 3

Hardware

• Switched out and remounted swivel pulleys

• Mounted 2 motors and attached motor covers

• Euric is modifying purchased L brackets into custom FarmBot compatible brackets

• UTM attachment system

  • Opened and disassembled the vacuum pump and cross slide gantry plate

  • Repurposing some Farmbot components to mount vacuum pump

  • Thinking we should use lacquered or treated wood instead of aluminum plate

Software

• Rewrote the 3 stepper motor code for 4 stepper motors

• Started editing the G-code for FarmBot C++ code

  • Outlined everything that needs to be changed within the code

Hardware - Goals for next week

• Have the brackets modified and aligned to attach last two motors

• Aim to have whole system done and ready for testing

  • Start attaching cable to spools and pulleys

• Figure out how to mount the UTM platform with cables

  • Be mindful of mass balance during assembly

Software - Goals for next week

• Finish implementing the G-code handler

Materials to Buy (decreasing priority)

1. Spools or wood materials to make spools

2. Deburring tool

3. Motors and motor covers (reach out to FarmBot to see if they have extra in backup inventory)

4. Mesh fencing for grid accuracy

   1. https://www.amazon.com/Fencer-Wire-Black-Plastic-Hardware/dp/B079ZN99CY

   2. Aim to have by next Tuesday

5. Swivel Pulleys

6. Rope Clamps

7. Soldering wire

8. Concrete/cement

9. Retractable cable management device

Current Concerns (decreasing priority)

Haven’t reached a point in our progress where we have questions

• Does the instructional team have any suggestions for electrical wire management of the UTM using a retractable, spring loaded mechanism that can extend and retract with the movement of the UTM?

  • The UTM needs to be powered, and will therefore be hooked up with wires. Given the constant movement and repositioning of the UTM, we need a way to ensure that electrical wires do not become excessively long and entangled with the cables.

  • (Further Described in Upcoming Goals)

Feedback from Meeting with Instructor

• Rationalize why we are using four posts

  • What if a user wants a triangular plot?

• Will we be attempting to simulate garden plots with more or less than 4 posts?

Answer: the positioning is arbitrarily defined and the math can be adapted to fit any geometry

Answer: Though the four posts are in the shape of a square, the posts can be replanted to enclose whatever size or shape garden plot they want. The shape of their garden plot (if triangular) must fit within the boundaries of the four posts

• Presentation feedback - not much room for improvement 😀👍

• Slide 3 - design decisions

  • Create a flow diagram that illustrates how we plan to achieve our final goal

  • Currently, what is stated on our presentation is very high level

  • Elaborate on the specific steps and benchmark goals and demonstrate the order in which they will be completed in order to achieve final goal

• Slide 11 - design constraints

  • Use meaningful graphics

  • Elaborate on the constraints with the specifics that we explained during the presentation

• Additional ways to stiffen and stabilize the frame without the use of concrete

• This doesn’t necessarily prevent the entire system from being knocked over by an external force - need to be weighted and bottom heavy

Feedback from Meeting with Sponsor

• Send Nick the list of farmbot components and he can purchase

  • He can reach out to FarmBot creators and see if they have emergency reserve of any items that are “sold out” on the website

• Currently designed FarmBot has not fully worked out kinks with homing procedure

  • Users still have issues with it

  • It is still a big open question for everyone

• Using 5 gal buckets - put a little bit of concrete mix and then stick extrusion into it instead of trapezoidal prism shape in sam’s pic

  • We can choose a bracing/embedding solution which suits our short term prototyping needs and not necessarily long-term usage

• Construction Wire for testing positional accuracy

  • Welded Wire Fencing - Fencing

  • https://www.lowes.com/pd/Tenax-Actual-100-ft-x-4-ft-Safety-Snow-Orange-HDPE-Construction-Fence-Fabric/999977028

• If we need feedback on user documentation visuals send to Nick

• Cable management - talk through with Nick - send questions, set aside more time

• Within the next two weeks (end of week 5)

  • Have machine in state where we are testing positioning

  • Beyond the design phase - should be done assembling and sourcing parts

    • Order parts to improve system by end of week 5 (latest)

Upcoming Goals

Weeks 5-7

• Mount all motors and new spools

  • Either buy or create with general wood components

• Test positioning accuracy with only 3 stepper motors and current code

  • Construction tape or mesh for grid

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

• Motorize the fourth motor/cable and adapt code to incorporate all four motors in positioning

• Assemble UTM and cables to plate

Weeks 8-10

• Motorize end effectors for functionality

• Electronic Cable management

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

  2. Tensioned Cable Reel or similar solution

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

Budget Remaining: $2177.47