Assistive Robot Arm

CAD of robot arm in full color

Inspiration

The inspiration was that it is a cool idea to make a robot . It was decided to create a robotic arm just 3 hours before arriving at Bitcamp.

What it does

This is a robotic arm with 4 degrees of freedom (4 drive-able joints). So basically it has 4 motors and can move in four different ways and each motor is controlled with two buttons to move forwards and backwards.

How we built it

The ENTIRE thing was designed, prototyped, manufactured, programmed, and troubleshot Friday-Saturday at Bitcamp. It was designed and simulated in Fusion 360, then 3D printed on cite at Bitcamp. Three of the motors are stepper motors and the last is a micro servo. It is all controlled with two arduino unos and thus coded in C.

Challenges we ran into

1) Original source of power (iphone 5V wall charger) did not work for some reason/ Solution: We got a 7.4v battery to power the motors. 2) Not enough pins on an arduino to run 3 stepper motors and a servo/ Solution: We used two arduinos to control the arm. 3) (happened 4 times) The 3D printer used to make parts was not working/ Solution: We turned it off and on again 4) For each motor, the buttons only moved the motors in one direction/ Solution: Each stepper motor has four poles, a positive and negative. If you apply a current across a pole, the motor will move one step (a fraction of a rotation). Now each pole has to fire in a very specific order so it has continuous smooth rotation. We had the firing order for the poles wrong so it would mess up kind of randomly. TLDR: The motors works in a very specific way and we didn't have the code written correctly for the motors. Solution/ We fixed the code so the motors do work.

Accomplishments that we're proud of

1) A robotic arm designed, produced, programmed and troubleshot at bitcamp in the <2 days. 2) Successfully coding the stepper motors using stepper motor drivers 3) Applying for the Best Hardware Hack, Best First timer hack, and Best "Bitcamp" Hack

What we learned

1) How to design and 3D print with a tight time constraint 2) How to control stepper motors with an arduino

What's next for Assistive Robot Arm

Surgical Robot Arm

Built With

arduino
autodesk-fusion-360
c
cura
pronterface

Submitted to

Bitcamp 2022

Created by

I designed the robot arm in fusion 360, simulated motion to ensure proper function before construction, 3D printed the parts, and assembled the robotic arm.

Benlexhi Serrano
I worked on assembling the components, wiring design, and some Arduino coding.

kanguyen18
I worked creating functions to run stepper motors from the ground up, without using a library. This was a good experience for me because I learned how to control base physical properties using code. I also found ways to overlap the pins used by the 3 stepper motors, so that they can each be controlled individually, but they take fewer pins.

Jeremy Kuznetsov
Khai Nguyen