Chocolate Press

This project was a VTSU/VTC associates capstone for The Company. The members of this project were Elijah Cass and I (Keith Carrara).

The first step of the project was to define the problem, to do this Elijah and I called the representative of the company to get specific details about the problem and its requirements, resulting in the document presented on the right.

In summary the project objective was to design and produce a prototype chocolate press as a secondary process replacing manual processing of chocolate pieces that come out too large from the primary process. The design must meet food and operational safety standards in addition to performance and size requirements.

The CAD screenshot above is the screenshot closest to the full initial design, having been taken a week before the initial design was finished being modeled. One of the major details of the initial design was the teeth being spikes with the idea being if we could find golf spikes made of 304 stainless steel (to meet the food safety requirement) we would use those as the teeth for ease of maintenance due to the dark chocolate being known to wear down 304 stainless.

Between weeks 2 and 3 on the project we dropped the idea of replaceable teeth with a the design in the image to the right due to no golf spikes the made of 304 stainless steel being found in the time spent on searching as well as attempting to reduce the complexity of the model and manufacturing. 

Alongside that change, the reinforcements were removed on the adapter plate which sits between the crushing plate and the piston as it was determined the forces experienced were not high enough to warrant the reinforced material.

By week 4, a majority of pneumatic and electrical components were selected with the pneumatic components being added to the design. Alongside these components, HDPE panels were added to the sides for safety. The electrical and pneumatic diagrams are shown below.

Since week 4, the major changes were an air flow regulator was added and the vibration assembly modified multiple times in attempt to find an optimal orientation and placement for the vibration motor and support from the isolators.

To the right is the slideshow which was presented at the end of my 4th semester summarizing the project problem, process, and solution. Below the slideshow is the final report which was submitted a week after the presentation.

As indicated in the slideshow (Slide 14), not all requirements were met at that point, leading Elijah and I to continue working on the project over the following summer to finish the project. Elijah milled the final parts resolving the thin input and food safety requirements which finished up his last task on the project.  During that time I continued tuning the vibration system believing the slow speed on vibration was due to  the mass being vibrated (vibration tray). Through further testing I discovering the source of the vibration movement issues being the vibration motor's location and orientation not to mass as I had originally thought. 

I began researching how to solve the issues with the vibration movement system while minimizing changes to the existing main parts that were produced (particularly the bottom plate which already had bolt holes).  Throughout this process I stayed in regular communication with The Company Representative regarding the difficulties being experienced, which by shortly into the following semester (my 5th semester) resulted in the determination to switch to a manually fed system removing the automated feed requirement. I began drafting the updated feed design and making plans for getting it produced given my limited time after classes that semester, when the decision to pass the project on to the seniors of that year was proposed by The Company Representative and agreed to by me ending Elijah and I's attempt to solve the problem.