In the final sprint, we assembled our final marionette and electrical systems and tested them in conjunction with the code; we finalized the mechanical design, which was mostly the same from last sprint, and constructed the final marionette and case. A major design change this sprint was switching from a two motor plate design to a single motor plate design. We did this by only using the the rack and pinion system for the lateral motion in the arms, instead of arms and torso. The rack and pinion system works as expected, although occasionally over or undershoots slightly due to the low quality of motors used. A major takeaway for a future team building this project is to use servos or less cheap motors because they are able to be more accurately controlled.   

With the mechanical system complete, we calibrated the code to control the motions correctly  via the motors and rack and pinion. We also tested that the new buttons worked with the rest of the electrical system and resulted in the production of the correct motions (we made sure that the 'jump' button didn't cause a 'march' motion when pressed). We also switched over from a breadboard to soldered electrical components for a more durable end product. We created the decorations for the marionette case and hid the electrical and mechanical components within the top and bottom of the case so that they would not detract from the aesthetic. Lastly, we finished the website and documentation, so that future teams can see what we did and how we did it. Because we continously integrated throughout our previous sprint, most of the work in this sprint was simply assembling and testing new components against each other and smoothing out flaws. 

With our last few weeks rapidly drawing to a close, we have completed our last shopping runs and filled out our final online ordering forms.
​
Over the course of this project we have spent $220.71 of our $250.00 budget. Our purchases were from Amazon, Adafruit, Home Depot, and Joanne’s. We bought spares of a few items at the time of purchase, such as the screw eyelets and motor shields, in case something broke or went wrong. We used one of our 2 packages of eyelets and 2 of our 3 motor shields. We were also able to obtain scrap wood and foam for our earlier iterations from the stockrooms, and later used PLA from Olin to 3D print our spools and chassis. Throughout the project we have used motors supplied by Olin’s Mech-E stockroom, and electrical components from the ECE stockroom, both of which are free resources to Olin students.

For a breakdown of how we spent our budget please see our bill of materials, attached below.
​
List of Materials Present in the Final Product:
-   ¼” MDF,  2 sheets of 2’x4’
-   4  1” square dowels,  38” long
-   1 zinc plated rod 36” long ¼” diameter
-   1 pack of 100 woodscrews #6 ¾” (used 40)
-   1 drawing mannequin, 18’’
-   1 pack screw eyelets (used 7)
-    50 yds beading wire D=0.008 (lots to spare)
-    2.5 yds fabric
-    2 motor shields
-    1 arduino uno
-    6 buttons (Momentary N.O. push button)
-    1 power supply
-    8 BO2 motors
-    Circuit components
       -  10 yds electrical wire
       -  10k ohm resistors (one resistor per button)

In sprint 3, we built a basic electrical system, consisting of an Arduino controlling 10 motors via 3 Adafruit motorshields; this system worked, but we were still controlling the motions via serial bus off of our laptops, but we certainly didn't want that for our final project. Previously, we had used a single button to cycle through motions, which was also not the desired behavior. We wanted one button per motion so that it is easy and intuitive for a user to interact with.

In addition to the motors/motorshields/arduino assembly that we build in sprint 3, we also built 6 identical circuits on a breadboard to be used for the buttons. These circuits would be closed when the button was pressed, and the input to the Arduino was positioned to pick up on this change. We used an Arduino library, EasyButton, to interpret the inputs from all 6 buttons, and change the marionette's motion appropriately. We got this working after some bugs; for sprint 4, all that is left on this part of the electrical system is button replacement with the final buttons (in this sprint we used the tiny PoE buttons) and some wiring to make things fit inside our project. 

It's time, time to assemble! Kinda... 

Coming into Sprint 4 the mechanical sub-team had a lot to do, but once we had our final puppet built we were feeling motivated and excited! The next thing we had to focus on was actuating everything else :P

​Once we had the lateral motion we moved on to assembling our final case. This involved laser cutting out all of the pieces and screwing them together with a combination of detailed finesse and brute force. During this step we also worked with the electrical sub-team to place the motors. We redesigned the top box to hold the motors on one level instead of two.    ​

We then moved on to beautification! This involved designing and creating the curtains for the case. The curtains serve two main functions; the first of which is visual appeal, the second, hiding unwanted wires. Originally we were going to cover the four posts as well as the top, however some unforeseen complications arose (namely needing to be able to access the top box) and we decided to forgo covering the top so we could continue to open the top box.   

In the previous sprint (sprint 3), we assembled and tested our complete electrical system. This consists of an Arduino connected to 3 Adafruit motor shields which control 10 motors, and 6 push buttons connected to the Arduino via a breadboard. We used tiny PoE buttons and the PoE motorshields to test, and got everything working.

In sprint 4, we finally received our buttons and motorshields for the final project. We assembled the button interface for the front of the case and soldered and prepped the motorshields for use. We wired the motors to the motor shields. We  also wired the buttons to the circuit used for the Arduino input on the breadboard. Lastly, we hooked the Arduino and motorshields up to our power supply. It should be noted that we reduced our design to include to 8 motors and 2 motor shields in this sprint due to some simplifications in the code and mechanical design. This system can be seen in the picture below, and is the final electrical system that ended up in our project. 

Now that we've reached the end of Sprint 3 what do we want to do to keep moving forward? Since this is our final sprint it's time to think about final decisions and assembly, as well as any tasks we see as possible risks that might cause problems as we continue on.

During our last meeting we came up with our tasks for this final sprint and what we think needs to be done to complete this project. The first item is the construction of our final base. This involves multiple sub-tasks since we still need to laser cut the cadded parts, assemble our final motor lineup (including the rack & pinion), and finalize stage appearance (curtains, plaque, etc.) Mechanically we also need to finish designing and building our final wooden puppet, in this case we plan on using parts from a wooden drawing mannequin. Aside from these tasks we also need to finalize our control system. To do this we will be integrating our new buttons into the final case design and looking into how we could incorporate voice control.  
    
There are a few possible risks that we think are important to think about in order to prevent complication later in Sprint 4. Our first main concern involves how we are controlling the puppet (buttons or voice control). While we have tested and worked with our current buttons we just ordered a new variety and need to go through that testing and integration again. As for voice control we merely have a lot of research ahead of us to figure out if this is even a feasible task to set. Mechanically we also have a few concerns with lateral motion, since we haven't completed this part of the design yet, as well as the fact that our motors seem to over-run, requiring a lot of calibration. 

While we do have a lot to do and will inevitably come up against unforeseen challenges we are excited to push on strong into our final sprint!