Week 8 Update
In this week, the problem with the short movements have been fixed. The motors are know strongly enforced by hot glue to stay in their place even if a force is acted on it. The coding was needed to be slightly changed of the placement of the keys - a simple fix as a result from putting the motors back on. A button was added, so whenever, it is pushed the cat starts to play the song on the xylophone. In the first meeting of the week (lecture), the cat was programmed to play a simple melody and discussed a new way on how to cover up all the wires and components. It was obvious, all those parts could not be put in the cat, not because it will not fit, but because the team didn't want to mess up the placement of the motors and the mallets that there already in the cat. 3D printing, laser cutting, and cutting wood by hand was the three options. the covering was created in SolidWorks with the exact dimensions (see below). We submitted it to the 3D printers, but later realized the covering was too big for 3D printing. This matter was pushed up to be concerned with in week 9. In the second meeting (lab), the cat was finally programmed to the desired full song, which the team calls "Gloria Had A Little Lamb."
![]() |
Covering |
Week 7 Update
The group came up with several ideas on how to fit all the hardware components and wires in a place that can be hidden. Of those ideas, only two made it to the final decision. The first idea was 3D printing the skeleton, as mentioned in the previous posts. However, in this week, the team experimented with Kinex that could function in the same way. The Kinex held on to the motors. The mallet-motor connectors were not 3D printed yet, so instead another creative approach was needed. A straw was cut short and held on to the motor with rubber bands as a temporary solution to connect the mallets to the motors. After that, the cat puppet was placed over the Kinex parts. This process took several attempts before it was succeeded. After successfully doing so, the cat had trouble moving its arms. The arms were expected to move in their programmed full swing, but instead, they were doing small movements. The motor had fallen off the Kinex skeleton when putting it on.
Week 6 Update
The project officially has an approved fabrication part: a 3D printed connector of the motor to mallet (see Figure 1). This part is authentically created by the team through SolidWorks. It's still in the process of Drexel 3D printing. There have been improvements to the final machine sketches. Since, there are more than one sketches, a few of the parts will have their own sketch (e.g. skeleton). Holes in the hands of the cat were cut to let the mallets in (see Figure 2). Immediately, the group realized that the mallets had a tendency to move around. The skeleton, which would hold all the parts in the cat, have also been 3D modeled in SolidWorks (see Figure 3). And lastly, a schedule was made for the next two weeks, so that the project progresses in a timely manner. At the same time of all of this, it was time to think about to put all the parts in the cat. Several ideas came up and are mentioned in week 7 update.
Click here to see schedule
Click here to see schedule
![]() |
Figure 1 |
![]() |
Figure 3 |
Week 5 Update
Before, the group had only one arm to play the xylophone. Our final prototype would have two, and so the coding was changed and two more motors were added. The xylophone that was bought before had only one mallet in the package. Another mallet could've been made out of wood, however, it was easier to just buy a pair that was exactly the same (for aesthetics reasons, as well). See below for the link. The breadboard was updated to a much smaller size. It used to be the approximately the size of a smart phone, and now it is smaller than a credit card. The new breadboard was not bought, but was in possession of the coder of the group. The coder also had an Arduino kit of his own, so most of the electrical parts are from him. To see if the new breadboard is compatible, a multimeter test was done. Last week, the cat puppet as the project's body was bought, and now it was delivered. A few things was changed because of this approach. The coordinated movement now involves the tail to move, and arms to play the song, and possibly the head looking down when it plays. The eye movement will no longer be needed. A skeleton must be placed inside the cat puppet to hold the puppet upright and hold all the parts in place. This task is expected to be the hardest mechanical task of this project. K'Nex was rented from Drexel resources to see if it can be used. Other ideas included 3D printing the skeleton or making it out of popsicles. During this week, the group was also assigned with making a presentation of what was completed so far (the link to it below).
Click Here To View Week 5 Presentation
Click here to buy the mallets
Click Here To View Week 5 Presentation
Click here to buy the mallets
Week 4 Update
During this week, two songs was hardcoded through Arduino: Mary Had A Little Lamb and a song completely created by our musician. This task was supposed to be the testing phase, but since our musician is also the group's coder (strong in both areas), the testing phase which was planned to be a span of three weeks was cut down to one. Because of how fast this task was completed, it cannot be considered the testing phase anymore. That was when we decided to change our route from having a testing phase to making our project aesthetically pleasing. The quickness of this completion also made the group think about more ideas, such as adding a button for different songs being played and putting lights around the xylophone. In the previous week, the challenge was how to successfully connect two motors together. When the small motors were delivered, it just so happened that hot gluing them together was not needed because rubber bands were enough to tightly hold them in place. However, this does not mean we will not glue them together during the final phase of the project. As a backup, a 3D CAD model was drawn through SolidWorks if the group wanted to go through he 3D approach (see Figure 1). Along with that, effort was made to 3D model the body of the cat, so that it can be 3D printed for aesthetics. However, that idea was soon discarded because of none of the group members had enough experience with SolidWorks to make the body actually visually appealing (see Figure 2). We looked through Amazon and found a realistic cat hand puppet (see Figure 3). This would be perfect because we put all the intricate parts (breadboard, wires, etc.) in the cat puppet, normally where a hand would go. The link to buy it can be found below.
Click here to buy the cat puppet
Figure 1:
Figure 2:
Click here to buy the cat puppet
Figure 1:
Figure 2:
Week 3 Update
The group was faced with a rather challenging issue: how to connect the two servos together. The purpose of those two motors is to allow up-down and left-right movement (see Figure 1). One of the motors (pointing upwards) rests on the holder of the stand, which will provide the left-right movement. The other motor is placed on top of it, but is laying on its side with the motor pointing to the side. This will provide the up-down movement. Having the motors tightly connected is crucial because it contributes to how accurate the keys are being played. A wooden connector was made (see Figure 2), but it was too bulky and restricted motion. We decided to buy smaller motors (link below), so that we can hot glue them. The motors we have now are rented from the school, so we cannot do anything permanent to them. Once the motors were delivered, the group tried to two motors with rubber bands first. The rubber bands work so well that the idea of gluing them together was ditched. Now, with the smaller motors, the coding to hit each key was started, and was finished by the end of the week. A sample code will be found below. Simultaneously, rough sketches were made of the overall appearance of the project and it's pseudocode. Both of them will also be provided below.
Click here to buy motors
Click here to preview sample code
Click here for rough sketches and pseudocode
Figure 1:
Figure 2:
Click here to buy motors
Click here to preview sample code
Click here for rough sketches and pseudocode
Figure 1:
Figure 2:
Week 2 Update
Two members (Gloria and Tanbir) of the group started to initiate the designing process of the arm. At the same time, the other two (Scott and Robert) began their code to program our two servo motors. Firstly, we create a stand to hold both motors and to act as a skeleton prototype to hold the cat upright (see Figure 1). Instructions on how to create the stand can be found in the blog's Tutorial section. We encountered our very first challenge of the project: how to connect the two motors that will help maneuver the xylophone mallet. For now, we are holding the two motors together with tape - a lot of tape. Furthermore, we found an ideal a 3D model of an ideal body we could use (see Figure 2).
Click here to buy preferred xylophone
Click here for 3D model cat
The following is a short video of testing our motors and its code:
Click here to buy preferred xylophone
Click here for 3D model cat
![]() |
Figure 1: Xylophone Stand |
![]() |
Figure 2: 3D Model Cat |
Week 1 Update
We focused primarily on two things in order to create a strong foundation for the project: brainstorming and the proposal. Our theme of the project we all agreed to do is music. We began to form a couple of ideas on what our animatronic device should take shape of. Our thoughts went from creating a moving military drummer, at first, to a moving cat drummer because we felt the need to make our device more creative and appealing to youngsters. That was when we decided on the intent of this device to be solely for an entertainment use for little children. We were also inspired by a viral video of a cat found online. However, we then wanted to change the instrument used to a xylophone, so that the cat device could actually create a song and not a beat. We didn't want to betray the idea of having the cat moving its arms to drum (see Figure 1), and we were limited in creating a melodious song if we used the drum in comparison to the xylophone. This process of actually having the cat to playing a beautifully sounding song will be our testing process. So then, we discussed how we can make this cat-xylophone device have life like attributes for it to be an animatronic device. We concluded on three different coordinated movements: have the eyes blink, the ears move, and the arms move to play a song. Right after that, Robert asked our artist, "What should we name our cat, Gloria?" A light bulb went on in my head. One of the things I kept on the back on my head is what we should name our animatronic. It had to be good and catchy, I thought. We all agreed on the name, Gloria The Xylophone Playing Cat. Another question was raised and that was how can we actually create this animatronic. Is the creating process reasonable for us, Drexel freshman, or was it out of our reach? After researching (link found below) and analyzing the resources we have, we knew we could get this project completed in a ten week span.
Link: https://www.youtube.com/watch?v=kA_pbMR6jVs
Link: https://www.youtube.com/watch?v=kA_pbMR6jVs
![]() |
Figure 1: Brainstorming ideas (e.g. multiple motors for the arm) |
Subscribe to:
Comments (Atom)