The Idea of this project came to my mind accidentally when I was searching for the different abilities of robotic arms to weld, then I found that there is a few who covers this area of usage (Automated Welding & Soldering Robotic Arm).
Actually I had an experience before for building a similar projects, but this time was very useful and effective for me.
Before decided the shape of it I saw a lot of applications and other projects especially in the industry field, Open source projects helped me a lot to find out the right and suitable shape.
That’s because of the science behind the visual feeding for our brains.
At first I saw a lot of professional projects that wasn’t able
to implement because the complexity of it.
Then I decided to see to make my own product inspired by the
other projects, so I used Google Sketch up 2017 pro. each part was designed to
assemble beside each other in a specific order as shown in the next picture.
And before assembling it I had to test the parts and choose the
suitable soldering iron, this happen by drawing a virtual finishing project as
a guide for me.
These draws shows the actual finishing life size shape and the
correct dimensions of each part to choose the right soldering iron.
Operating and Installation
During the work I faced some obstacles we have to announce about
1. The arms was too heavy to be
hold by the small stepper motors, and we fixed this in the next version or
laser cut print.
2. Because the model was made from
plastic material the friction of rotating base was high and the movements
The first solution was to buy a bigger stepper motor that able
to bear the weight and friction, and we re-designed the base to fit a bigger
problem stills and the bigger motor did not fix it, and that was because the
friction between two plastic surfaces beside we can't adjust the pot by
percent. The maximum rotation position is not the maximum current that the
driver can provide. You must use the technique shown by the manufacturer, where
you measure the voltage while turning the pot.
Then I resorted to change the base design totally and put a
servo motor with metal gear instated of gears mechanism.
The Arduino board can be supplied with power either from the DC
power jack (7 - 12V), the USB connector (5V), or the VIN pin of the board
(7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and
we decided to buy special USB cable that support 5 volt from the PC or any
so The stepper motors and the other components works properly
with only 5 volt and to secure the parts from any problem we fix step down
The step down module is a buck converter (step-down converter)
is a DC-to-DC power converter which steps down voltage (while stepping up
current) from its input (supply) to its output (load) and also keep the
stability or the voltage.
After some modifications we changed the design of the model by
reducing arms size and make a suitable hole for servo motor gear as shown.
And while testing the servo motor succeeded to rotate the weight
180 degrees correctly because its high torque means a mechanism is able to
handle heavier loads. How much turning force a servomechanism can output
depends on design factors—supply voltage, shaft speed, etc.
Also using I2c was nice because it only uses two pins, and you
can put multiple i2c devices on the same two pins. So for example, you could
have up to 8 LCD backpacks+LCDs all on two pins! The bad news is that you have
to use the 'hardware' i2c pin.