Description

Aggie Chocolate Factory sells hot chocolate using a Mesoamerican chocolate made in house. The chocolate is ground into powder for ease of mixing into steamed milk as customers order hot chocolate.

To create the chocolate powder a food processor is used to grind the chocolate into fine powder. The remains are sifted to separate the powder from larger pieces. The larger pieces are put into a grain mill where a spatula is used to push the pieces into the mill. Powder is collected from this step and added to the powder that was previously sifted. Any remaining chunks are reprocessed or discarded. Each machine generates heat while grinding the chocolate causing some chocolate to melt to the blades of each machine. When this happens, chocolate powder that is not yet melted is more prone to melt as it sticks to the already melted chocolate, resulting in unusable product.

The goal of this project is to design a new machine that eliminates unnecessary steps, doesn’t melt or waste the chocolate, turn solid chocolate into powder, and require minimal effort from the operator.

Design Description

To Accomplish the task of making an efficient chocolate grinder design, we went with a rotary grater design, reminiscent of a rotary cheese grater.

The primary goal, given this basis, is to find a way to automate the system. After three iterations we produced a segmented design. First there is the control box, which contains the motor, emergency stop, on/off switch and electrics.

Connected via supports and a machined connector, is the input/output section. Solid chocolate is fed into the top, where a weight pushes it down into the grater mechanism. The grater mechanism then grinds it down into a fine sand-like powder, perfect for mixing into hot chocolate.

Performance Review

Numerous tests on the current design have been performed to check these threshold goals and values, primarily by a full run-through test. If the machine can grind down a full block of chocolate and remain within threshold measurements and values, it is successful.

Conclusion

In conclusion, there were a few setbacks to this machine, but this simplified design makes for an efficient process.

In terms of requirements, It boils down to just a few main ones. Said main ones include: the machine being made with food safe materials, a reliable/robust design which can run for long periods with minimal human interaction, and a temperature threshold in the vicinity of the chocolate not exceeding 90°F.

Lessons learned throughout the design and building phases are mainly around ensuring that chosen parts are adequate for the project’s needs, and good communication about desired parts. One example of this is the motor. At first, we didn’t check to know how much torque we needed from a motor and made an assumption that a motor we found would be good enough. It was not, and in the end a motor with sufficient power was found. Said motor worked correctly because there had been more testing and checking of specs before the motor was ordered. Through all of this we were delayed by over a month.

Some future work planning we thought up includes things like a silicone mold for the solid chocolate, and a smaller pusher for the top,