Author: afiol

This past week I did not accomplish as much as I had hoped due to having multiple exams and assignments due. The main thing I completed was adjusting the 3D-printed model to fit snuggly around the solenoid rather than loosely fitting and getting stuck after retracting. Using this new design/information, I can replicate it across the entire chassis design so that the solenoids do not move as much and get stuck. Aside from this adjustment, I did not accomplish as much as I had hoped to.

In the coming week, I hope to finish much more. Now that classes have finished and I have almost all of my other assignments completed, I hope to be able to dedicate much more time to completing the chassis. Other than replicating the new dimensions mentioned above, I have to add some support to hold the chassis up while it is suspended over the piano keys. Additionally, we went out and bought metal rods so that the chassis could rest on top of them and suspend over the keys. With these two additions, the chassis should be successful in hovering over the keys, and the only thing we need to ensure after that is that it presses the keys when needed. If that is not successful, I plan on making cylinders to extend the solenoids’ reach so they can press the keys. Once all of this is integrated, it should successfully press down on the keys!

I hope to have a new Solidworks model as well as a freshly printed chassis model by Wednesday. If both of these are successful, we should be set for demo day. If not, we will continue iterating up until demo day.

This week, my main focus has been finally printing out a prototype of our chassis structure that will hold up the solenoids above the piano keys. This has taken so long because we have been trying to sort out the logistics of 3D printing due to the cost of printing on campus. We finally have a prototype that has given me insight into what needs to change for the final solution.

One major issue was the holes that the solenoids protruded from were too small for them to return to. We also gave them too much wiggle room where the walls held them in place. Thus, I increased the diameter of the holes and made the walls tighter around the base of the solenoids. Another issue that we are having with this design is the difference in height between the black and white keys. Therefore, we somehow have to create an offset between the black and white keys so that all of the solenoids are close enough to their respective keys.

Going into the final week of classes, my progress is a little behind schedule. It would have been nice to get this done a week earlier, but we were constrained by logistical reasons.

This week, however, I plan on finishing a new design and hopefully being able to print it out before the week ends so we can squeeze in one or two more alterations that may need to be made before demo day.

Heading into the final weeks of the semester, and thus this project, I have run one primary test for my part of the project, and that was ensuring the power consumption of the circuitry does not exceed 60 W. This goal has been met since we limited the number of solenoids that can be turned on at once to five, since each solenoid draws about 0.9 A and uses 12 V this requirement has been met and tested. Additionally, if this proves to be troublesome in the coming weeks, the voltage can be lowered, reducing the current since each solenoid doe not need 12 V to operate. I will also be helping measure our maximum tempo since the circuit will be a limiting factor due to its physical characteristics. Hopefully, we will be able to meet our preset quantity, but that is probably unlikely.

In addition to the interim demo, the image above is what I have accomplished this week. I realized that there were a couple of issues with the previous version of the chassis design. One of the major issues was that the black and white keys were not actually aligned properly in my previous design. Another major issue was that we wanted to allow the system to be placed over any octave on the keyboard, but after some more careful measurements, I realized this would not be possible for what we had in mind, so I had to redesign the chassis nearly from scratch. Additionally, the previous design was under the assumption that we would just secure the solenoids to the inside of the chassis, but to plan for problems arising for demo day, we switched to a design that would allow for solenoids to be replaced easily. Overall, I believe this is a much more robust and easy-to-use design, and hopefully, it will be suitable for demo day.

I am still technically on track, but I would’ve liked to 3D print a prototype tomorrow, and I’m not sure if I will be able to since I am currently having difficulties with Solidworks right now. Hopefully, I will be able to figure out my problem with enough time to 3D print tomorrow, but if I don’t, I will try to print something out Monday. I hope I can print it out tomorrow, though.

Next week I hope to have a prototype of the chassis completed, and if it does not function properly, I hope to update the design and print another one before the week ends. The end of the semester is coming soon, so I need to finish this by the end of next week.

This week finally got around to playing with Solidworks. I was able to generate a basic rendering of what we had in mind for the chassis design. I am still working out how much wiggle room we have between solenoids, but otherwise, I should be set to 3D print soon.  Unfortunately, I am not finished with the Solidworks rendering and would like to add some additional features to it, so I will focus on that tomorrow. Here is the 3D rendering that I am currently working on:

From my last status update, I am more or less on schedule. I was not able to get a copy of Solidworks until yesterday, and even then, I had to get a new license from the software catalog and sit through an hour of download times. Tomorrow, however, I will be cleaning up the rendering and adding some features to the design to hopefully improve the overall performance of the accompanyBot.

In addition to the work I will be doing tomorrow, I also hope to figure out how to 3D print, how expensive it is, and how to generate the files necessary to print it out. I also hope to help Nora and Rahul with the serial communication if they do not finish it before the week ends.

This week I was able to take measurements of the piano we will be using for the final demo. This allowed me to finalize some measurements for the final chassis design. The spacing of the full octave is about 6 cm, the width of one white key is 2.1 cm, the width of a black key is 1 cm, and the distance between the black keys is a maximum of 2 cm and a minimum of 1.7 cm. This will introduce some design constraints since the width of the solenoid is a few millimeters larger than the width of the white keys. This has caused me to rethink the design of the chassis. We may need to alternate sides of the chassis that the solenoids are screwed in to account for the extra space they need. I was able to get a rough sketch of the new design but was not able to complete it since I did not measure the keys until the end of the week. It should not be too much of a setback, but it does introduce some design constraints that previously were not considered.

I would have liked to get a better idea of what the chassis will look like with these new measurements, but I was pressed for time since I did not get them until the end of the week. In an ideal world, I would have also gotten a Solidworks rendering up by the end of the week, but I did not have enough time to log in to a CMU machine and play around on Solidworks. I am not far behind on my Gantt chart schedule, but I would have liked to be a little farther ahead of me now.

After my two exams this week, I would like to get a Solidworks rendering prepared and looked at by my teammates before sending it to the 3D printer. I would also like to place an order for the 3D printing filament and try and find some resources on how to 3D print since I have not done it since spring 2020.

This week I did not accomplish all the goals I set out for myself. Last week I stated that I wanted to have a full sketch of what the chassis will look like and possibly a Solidworks rendering of what I sketched. I was not able to get to the Solidworks rendering primarily because my Macbook cannot download it from the CMU software catalog, but I was running out of time this week trying to catch up on all the work I neglected to do over spring break. I was able to sketch a very rough idea of what we would like the chassis to look like. I also got some rough estimates on the dimensions of the solenoids and, using those measurements, the minimum dimensions of the chassis. My idea is to have a 3D-printed container with a wall down the middle for the solenoids to be mounted. With the solenoids mounted down the middle of the container, they will hover over the piano keys and press them when turned on. Additionally, two pipes will go through the container’s length and can be placed on the edges of the piano so that the chassis can hover over the keys.

As you can see above, this is a rough idea of what the chassis should look like. The top view shows how the solenoids will be placed in the container, with the top set of solenoids hovering over the black keys and the bottom set hovering over the white keys. Furthermore, the side view indicated roughly where the pipes will go through the container so as not to interfere with the solenoids.

This brought sketch has put me a little behind schedule since I wanted a little more detailed idea to be completed this week, but it is not the end of the world since we have so much slack time built into our schedule. Hopefully, this week I will be able to make up for lost time last week.

Some deliverables I plan to provide at the end of next week is a much more in-depth drawing of what our chassis will look like. Additionally, I would like to measure the keyboard dimensions to get a much more accurate idea of what the size of the chassis will need to be so that it fits on top of the keyboard. I also hope to get my hands on a copy of Solidworks so I can play around and figure out a good rendering to be sent to the 3D printer. I will also look into 3D printing filament that we will need to purchase to use the 3D printers in Techspark.

In the past two weeks, I primarily worked on the design report. I spent the last few days of the week before spring break writing and editing until we were prepared to submit. Aside from writing the report, I have put together a circuit of five solenoids controlled by an Arduino to determine roughly how much power they consume. Five solenoids turned on at once is our worst-case scenario, so I wanted to ensure that our calculations were correct and that they it does not exceed 60W. I found that if we power the solenoids with their maximum voltage (12V), the five solenoids only draw 4A of current, placing their maximum power consumption around 48W. Additionally, I was testing it with PWM signals, and the solenoids draw even less current. If we are strapped for power, we can use PWM signals instead.

(The image is a bit blurry, but it says 12V and 4.009A.)

This progress is on schedule with our most up-to-date Gantt chart. After spring break, I will begin to put some serious thought into the design of the structure that will hold up the solenoid circuit.

In the coming week, I plan on having a well-thought-up sketch of the chassis. Additionally, since we were thinking about 3D printing the structure, I would like to play around a get a mockup on Solidworks. My goal for the week is to provide something substantial for the course staff on what our chassis will look like.