Final Project Journal

For some components dimensions were easily found online, so I searched for those dimensions.

For other, either I couldn't find the dimensions online or there were a wide variety of the same product on the internet, I resorted to using the caliper to measure those components accurately.

I drew the sketches I had previously planned on fusion 360, but this time the sketches are drawn with proper accurate dimensions to accommodate the different components or to allow for good and easy to assemble joints.

I used a variety of joints in the project, the most used one was the T joint.

I extruded the sketches that I had drawn in the previous step as new components so that I could define joints between the different components.

The thickness of the extrusion was 3 mm to resemble the plywood sheets I will be using in the fabrication phase.

I did this for every unique 2D part in the project.

I defined joints between the different T slots in the design to check whether everything fits perfectly to prepare for the fabrication phase.

Some sketches are used in more than one part so I copied them to.

I downloaded some components from grabcad.com, namely an Arduino Uno model, Nema 17 stepper motor, a4988 stepper motor driver, and a large breadboard, I found the STEP file format to be the most suitable for me so I downloaded my models in it whenever possible.

I components I downloaded where used to check that all components will fit in their desired places inside the assembly.

Another reason for importing the models is to get the accurate and exact location for the screws need to fix the parts.

For most of the parts the part is exactly the same as the sketch defining it.

However in the parts where holes were made according to the imported models, the face containing the holes was projected onto a plane to create a sketch which can be exported in the DXF format.

I search for the dimensions of a living hinge, different spacing give varying degrees of flexibility, I chose my spacing to be around 2mm to given enough flexibility for the curvature I have in my design (diameter of 30mm) (tested for validation).

After designing the living hinges I have all the drawings I need to start fabrication, I just need to place them in the board in an efficient way, I used rhino for that.

I started the design as usual with a sketch, I sketched on the wooden part to ensure they fit together when they are fabricated.

I duplicated the part I sketched, made another extrusion on top of it to hold the stand, we'll call this part the rotating base.

After finishing a rough sketch of the rotating base I filleted the edges to be more comfortable to use in hand.

Also I noticed that the materials are getting mixed up so I changed the appearance of the wooden parts to resemble wood, I didn't color PLA parts black however because it's not the best color to model with as it hides most of the bodies details.

I then created the lower part of that stand with a bunch of extrusions

And just like what we did with the rotating base the bottom part of the stand was filleted as well to provide a more user friendly experience.

I added a hook to the part to hold a rubber band so the stand can grip the phone used as a camera in the device.

It started with a sketch in which I determined the shape of the hook then I extruded, and filleted it, mirrored it because we need two hooks and joined them with the rest of the stand part.

Similar to the bottom part the top part is very similar, and of course all parts are filleted to give a more refined look and be more user friendly.

I just selected the body I wanted to export and selected to export it as an STL.

The first step was to import the DXF file into laser works

Then I had to choose which lines are to be cut and which ones are to be scanned, in my case all of my lines were to be cut.

After selecting the mode to be cut I needed to specify the cutting speed and power, which in my case and according to the fab lab specialist were 15 for the speed and 78 for the power.

After that I should check for overlapping lines as they can cause problems.

The next step is to send the file to the laser cutter, track frame to ensure the laser will stay within the boundary of my board and start the cutting.

Cutting is complete.

This step is also very simple I just loaded the files to Cura, each file alone so that if something went wrong the damage is minimal.

I sat the layer height to 0.3 mm to print faster, the temperature to 215 to suit the PLA filament, the rest of the.

I then choose the location and the orientation of my part to minimize the supports as much as possible.

I also used the support blocker feature to remove the supports in the screw holes.

Preview the print, and create the gcode.

I try to name the part something descriptive, unique and contains useful information about the print such as it's time, weight the and materials used and its color, black PLA in my case, then I put the file on a regular SD card as the printer doesn't accept anything but such memory card.

The printer heats the bed, starts printing, I observe the first couple of layers to ensure everything is alright and come to check on it every now and then.

The parts are printed with good finish and can be used without any post processing.

The first part, the rotating base, took 26 minutes and 5 grams to print

The second part, the bottom part of the stand took 45 mins and 9 grams

The third part, the top part of the stand took 33 mins to print and 6 grams.

Assembling the parts was easy it was just a matter of fixing the T slot joints together with screws.

Other joints were used in different parts of the project where T slots weren't the optimum choice.

The 3D printed parts were also joined together with screws and joined to the wooden part via screws.

All the screws used in the project were M3 screws and their bolts, however they were used with varying lengths to achieve different goals and depending on the part.

This first section of the code is used to include the LiquidCrystal_I2C library to control the LCD using the I2C connection protocol.

The next step is to define some variables and pins to give them understandable names instead or arbitrary numbers.

The next block is concerned with the pin mode of the pins, whether they are outputs, inputs or inputs that should be pulled up.

In the next section, I initiated the serial monitor for troubleshooting anything that misbehaves in the circuit, then I started the LCD and started it's backlighting.

In this step I'm mapping the reading of the potentiometer which can take up a value from 0 all the way up to 1023 to a range of delay in microsecond that works well with the motor in the eighth step mode, the delay shouldn't be less than 100 microseconds and more than 2000 microseconds the rotation becomes so slow that it is boring.

In the next step I want the LCD to print the value of the delay, to make the program user friendly I started by printing a message that says what the LCD will be printing, then I moved to the next line and printed the actual delay stored in the variable t.

I sat a delay of 250 milliseconds so that the LCD doesn't refresh so quickly the text becomes fainted.

This part is concerned with the homing, the stepper motor should rotate in a direction that brings the carriage closer to the IR sensor as long as the carriage isn't near the sensor enough to make it's reading equals 0. This motion is not user controllable and it's speed it set to the maximum the motor can handle so that the homing can happen always to make the device usable at anytime by the user.

(The IR sensor gives 1 as a reading when nothing is blocking it)

The movement is done though a custom function called move which I created, the function takes in an integer as an argument and sends pulses to the step pin of the driver at certain intervals which is defined by the variable t.

The first stage was to mount the different components on the base of first part, the components mounted are the Arduino, the stepper motor, the breadboard, and the a4988 driver.

The second part was to install the IR sensor under the base to sense the carriage.

Then I tried testing the IR sensor to calibrate the its range

After that the whole mechanical assembly is assembled which includes connecting the motor to the lead screw via a 5 to 8 mm coupler, and attaching the lead screw to the end pillow.

Then comes the part of testing without the complete enclosure, I uploaded the code to the arduino and started testing

After the testing is complete it's time to assemble the controls onto the casing of the device.