Instructables
Picture of Plexi Bot: Wireless Robotic Arm
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 Hello all. Recently I have been working on a lot of robotic design and simulation at work. I needed a method of taking my work home with me, and seeing as I can’t carry a large six axis arm home in my briefcase; a solution had to be found. The following set of instructions is my initial design for a small three axis robot that can be used for simulation, small tasks, or just looking cool. This project uses a regular microcontroller, some small stepper motors, and some transistors. This project does not require any advanced equipment or in depth knowledge in robotics, all you need are some basic tools and a bit of work ethic.

The robot featured in the above picture is our final product. It is capable of rotating on three separate axis; rotation about its base, rotation at the base of the first arm, and rotation at the base of the second arm link. There are two levels of this robot, the first has a very basic controller, the second has a wireless controller and some more advanced controls. We will begin with the first design and then once that is finished it can be easily upgraded to the wireless version. The six buttons on the breadboard are use to control which joint is moving and in what direction is it moving. The robot can also be controlled using something called R-code. This code is similar to G-code for CNC, you specify which joint you are moving, the direction, and at what speed it is to move. This code is entered on the computer through a windows application included in these instructions.

So if I have captured your interest (which i hope i have) then I suggest you make every attempt to follow this Instructable and build this robot. Not only will you be able to automate the boring tasks in life but you will also emerge with a greater understanding of micro-Controllers and robotics. 


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gsandhu22 months ago

I’m working on a project which is about making a rescue
robot . I have struggling with it for 4 months and now all the mechanical works
had been done . but I’m facing difficulty in make the robot to work with rf
module can u plzz help me…

I want make transmitter and receiver that can control the
motion…I mean that receiver should have control 8 dc gear motor and each dc
motor should have a forward and backward botton to control the motion ……can u
kindly help me with this project ….if u can make the circuit board diagram for
the PCB ….or any other suggestion plz reply……mail me at “sunny1995gagan@gmail.com”

topdo93 months ago

Interesting Robot. I was wondering, since you are using stepper motors, how is the accuracy? Have you considered some kind of feedback for motor positions like encoders?

kevinhorne3 years ago
I'm new to field of microelectronics and have been working my way in on various parallel projects. This is an exciting and remarkable project for the site, thank you for posting it.

There were a couple of things I couldn't figure out between your wiring diagram and the images. If you have a moment, I was wondering:

1. Where on the wiring diagram are these two circled items? They look like some sort of capacitor loop, but I can't really tell without it being on the diagram

2. You list out a 1K resistor in the parts list but it looks like there are (7) 3.01K resistors called out on the wiring diagram and they appear to be ?

3. Can you provide a picture of the wiring occurring at the top of the bus runs on the larger breadboard and the precise location of the power feeds - just want to make sure I have things correct before I destroy my chips!

Thanks!
robotarm.jpg

5V given to 11,32pins, GND connected to 12,31 pins.

100nF capacitor between 5V and GND at both 11/12 and 31/32.

msuren886 months ago

what is the value of the condenser ???

plz give fast reply

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gany1437 months ago

Are the shapes of 1st arm and 2nd arm important?

i.e the figures arm shape which are present in the pdf file. Is it necessary to cut the plexi glass in such a way?? plz reply... :)

ianmcmill1 year ago
Very nice set up tutorial !
Cool thing.
sanjevk2 years ago
can we use atmega8 mcu instead of pic?b'coz in my region pic mcu's are not readily available...!
ortechltd2 years ago
5v stepper motors are not available in my country. how can i use 12v motors??please inform me ASAP
lordl99992 years ago
would it be complicated (for a know's-nothing-about-robotics (/another instructable would be appreciated)) to apply a third stepper for opening and closing a "claw" at the end of the arm??
*a 4th stpper motor
arick2 years ago
How can I make the initial position everytime the system is resetting ?
Or power off, then the hand return to the initial position ?
JordanN52532 years ago
Very nice looking bot, very interested in making one. There's just one thing I need to ask, you mention it can perform small tasks. What type of tasks can it do? Thanks.
lmateiu2 years ago
Hi!
It's nice,but did anyone tried with bluetooth?,because there is a very tyny USB/Bluetooth device for mobile phones and is not expesive...
gabrielsan3 years ago
Good work. Steepers are much more reliable than hobby servos for this job.
Mangokid (author)  gabrielsan3 years ago
Ya they most certianley are. The best part about them is that they dont have the backlash that the hobby servos do. If you look at some similiar bots with servos you will notice that they are extremly jumpy and usually swing all over the place. Also these stepper are geared to 1:64 so each joint has 11'000 diffrent positions over its 180 degree range of motion. I dont think hobby servos are that accurate
tigerbomb83 years ago
how much can it lift
Mangokid (author)  tigerbomb83 years ago
it will lift about 100 grams. If you turn up the voltage to 6 or 7 you can lift more but only for a while due to the heat generated in the motor