Wednesday 31 October 2012

Loader Bucket Completed!

      I finally completed the loader bucket today, the welding took a while because I was welding outside, and the weather has been rather dodgy lately. I used a Lincoln arc welder running at about 130 volts, with 7014 AC rods I believe. As you may be able to tell, I completely welded the patch to the bucket, covering every edge, gap, nook, and cranny. Generally it would have been easier(and maybe a bit structurally stronger) to just use a bunch of short welds spaced along the seams, however, it is a bucket that is used to haul manure and other liquids, so I needed to make sure that it wouldn't leak. Overall, I'm fairly proud of the job, especially since I've only been welding for a few months.
Before
After

Tuesday 16 October 2012

Robot Arm Components: Part II: The Control Systems

     Today, I'd like to go over the part of the robot that controls it: the computer. the computer's job is to take in signals from the computer, then interpret those signals and send commands to the various parts of the arm. These signals are in the form of a widely used code: ASCII(American Standard Code for Information Interchange). The purpose of ASCII is simple, in that computers only understand numbers, so ASCII is a way to use numbers to represent actions or characters that aren't numbers. For example, every single button on a keyboard has an ASCII number applied to it.

Ascii Table
An ASCII table
So, when you type in a command on a computer, the computer converts it from ASCII to a binary value, which the computer in the robot then accepts, and sends it in the form of electric pulses to the necessary part of the arm.  

Monday 15 October 2012

The Loader Bucket


 This is a loader bucket we use around the farm for odd jobs. As you can see, it's rusted out around the bottom. I'd thought I'd put my newly acquired welding skills to use at school, and build an inner plate to patch the rusted spots. (it's currently incomplete, pics will be posted of the final product).



    

Tuesday 9 October 2012

The Oscilliscope

     We purchased an oscilloscope at an auction about a month ago, thinking it would be cool to play around with. Basically what it does is measure the voltage over time. The picture on the right shows 2 different voltage over time readings. The bottom one is very much like what my robotic arm would be sending to the servos, each pulse is electricity traveling to the servo, and the width of each pulse is what tells the servo what position it should be in. The dials at the side of the screen allow you to change different variables, so that you can line up the wave with the graticule, and measure it better.
I have to say that I'm rather fond of the way the Oscilloscope looks, it gives a work area a little bit of the 'mad scientist' look.