Progress Since Week 4

Hardware

Saturday

• Installed the polyester braided cables into system

• Mounted all 4 motors and 3 of the motor covers

• Utilized rope clamps and swivel hooks to mount UTM plate

Tuesday

• Traced UTM plate onto plywood to be cut and drilled

• Cut wood for the spools and its flanges but still in progress

• Electrically wired all motors and connected to Farmduino

• Ran sequential motor code

  • Noticed errors with spooling and unspooling - motors moving in incorrect directions

  • Believe problem may be attributed to sequential spooling as opposed to concurrent spooling

  • Also noticed motors skipping or stalling - sounds like there is a lot of friction between motors and motor hubs

  • Also noticed improper unspooling - maybe not enough weight

    • Works best in constant tension

  • Noticed how the pulleys influence how the cables spool and unspool

Wednesday

• Plans to further implement code

• Plans to troubleshoot the spooling of the four different motors

  • Want to test the code without flaws in the components

  • If it’s free hanging sometimes the tension in all four cables aren’t equally distributed

    • Maybe have it rest on a platform from rest

• Go over homing

• Work on finishing UTM plate so that we can mount things and utilize realistic end effector weights

  • Wood is much lighter than the aluminum

Hardware Plans for Next week

• Determine a way to keep tension in unspooling

• Address friction in the pulley

• Address weight of end effectors

• Accuracy testing

• UTM plate and connections

• Wooden spools for those who don’t have 3D printers

CAD

• Assembled the entire system

• FEA on the frame to determine deflection results under realistic loading

  • Mass of UTM, vacuum pump, vacuum lines and then turned that into loading at an angle

    • worst case scenario is perpendicular to the extrusion

    • Maximum angle is based on motor torque

    • 50 N @ angle of 15 degrees below horizontal

CAD - Goals for next week

• Fatigue Analysis on system assembly

Software

• Wrote Farmduino capable code for 4 motors

  • Still in sequential activation as opposed to concurrent activation of motors

Software - Goals for next week

• Iron out the movement logic and implement into FarmBot C++ Arduino code

Future Goals

• Create user interface for user inputs into Arduino Code

• Look into FarmBot webapp to work on compatibility

Materials Purchased this week

• Wood for spools

• Plywood for UTM plate

• Files

• Rope Clamps

• Swivel Hooks

• Carabiners

• Mesh Grid

• Wood Glue

• Solder

• Greenhouse

Materials to Buy (decreasing priority)

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

2. Smaller diameter cables or bigger swivel pulleys

3. Retractable cable management device

4. Various types of seeds

5. Concrete/cement

Current Concerns (decreasing priority)

• Show the video in the presentation

  • Components aren’t behaving as expected

  • Ask for expert opinion on motor friction, stalling, and unspooling with cable tension?

Feedback from Meeting with Instructor

Materials to Purchase

• Ask Tom or Chris for deburring tools

  • Two types - one that is long that looks like bigger drill bit

    • Spinning curved one

• Tips - take larger drill bit and use by hand to debur

Concrete/Cement

• Matt has concerns with pouring and mixing concrete

• Quickset concrete - home depot 5 gallon bucket - mix with stick

  • Better than standard concrete mix but fulfills same purpose

Code Documentation

• Make it clear what parameters and math must be changed if they were to not use a four post system (i.e. 3 or 5 post system)

Four Post System

• Space constraint - the four post system addresses the geometric garden plot constraint

  • But the four post system still requires that space - dimension of the frame

Retractable cables - UTM cable management

• Spring

• Update the progress report current concerns to talk about cable tension retraction for electrical wiring

• Looking into tension cable reels that are adaptable to our system and cable size

Feedback from Meeting with Sponsor

• If we can’t find affordable alternative solution, don’t get stuck on it - just order a more expensive part

  • Don’t get too fixated on price for users

• End of week 5 - have system motorized and moving

  • Decide which homing procedure makes the most sense - simpler or more complex/accurate?

  • Nick is satisfied with the simpler one - doesn’t have to be the most accurate

• Make a list of custom parts that would be nice to have

  • As an alternative for sake of time, use FarmBot components to make a modular solution

  • Make CAD design - proper drawings with gd&t

• Concrete - have it designed such that users can change their mind and change configurations

  • Assume user doesn’t know how to mix concrete or use quickset and that it could be messed up

  • Asking a lot of the user to be able to place the uprights perpendicular to the ground considering they may not have experience with concrete or a way to measure the perpendicularity

  • Leave concrete as an open design question

  • If you bury the cement bucket under ground - more stationary

    • If you keep it above ground - more adaptable/adjustable

  • Decide on what works for us in this project but note that there are alternative methods

    • How would a target user respond to this design choice? Document it and explain rationale and alternative options

• Send Nick a link for the outdoor pop up tent we need and he may have one to let us borrow

  • Keep up the productivity regardless of weather

Upcoming Goals

Weeks 6-7

• Create spools with general wood components

• Test positioning accuracy with 4 stepper motors and current code

  • Construction tape or mesh for grid

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

• Assemble UTM and cables to plate

Weeks 8-10

• Motorize end effectors for functionality

• Electronic Cable management

  • 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: $1942.06