Embarking on this humanitarian engineering project, to serve a community abroad, during the time of the coronavirus outbreak, made it difficult for the team to connect with their users. In order to gain a better perspective on how to successfully complete a humanitarian project the team connected with a Santa Clara University Civil Engineering professor, Dr. Tonya Nilsson, who is experienced working with projects abroad. From her advice, the team looked into the ethics and social responsibility that they will hold as humanitarian engineers in designing, building, and implementing the GRVLR Rock Crusher.

As a humanitarian engineering project, there are many factors that need to be considered outside of the act of designing and building alone. Five of the most important constraints to the GRVLR project looked into by the team were manufacturability, sustainability, economic viability, social impact, and health and safety. A major concern of the GRVLR project is keeping the unit cost low. Sunita Bhandari emphasized to the team the value in the women being able to pay for the device in some capacity. There is a certain sense of pride and enhanced responsibility that comes from being able to purchase things for oneself, as opposed to simply receiving them as charity. It was proposed to the team by a representative from the Himalayan Climate Initiative, Shilshila Acharya, that if the product proved beneficial to the target community it could be subsidized by the government. In this case, the government would pay for the construction of the device and then sell it to the women at a lower, more affordable price. 

The GRVLR rock crusher is designed with a focus on cost efficiency and durability. The rock crusher is designed to be operated for at least six hours a day continuously and so is made of highly robust parts. The crushing weight and plate are made of .5-inch thick low carbon steel. These parts will be sustaining the greatest impact. According to the material analysis conducted using Granta EduPack, the hardness of the plates and the fact that contact between the plates and the rocks will be mainly straight on impact resulting in failure due to fast fracture and yielding, it is predicted that a long time will have passed before sufficient wear will have compromised the overall machine function. 

 

Due to COVID-19 setbacks, there was not enough time to test this hypothesis, and as such confirmation will need to be achieved by the future team to take on this project. The frame of the machine is steel tubing reinforced with steel sheet metal, this makes the machine robust enough to avoid warping during operation for optimal rock crushing, but also makes it strong enough to withstand years of use and misuse without failing. The bearings used are also sealed in order to prevent any outside material from getting in and obstructing their movement. The only part that may require some maintenance would be the chain, which may need to be cleaned and lubricated. This maintenance is extremely cheap and can be performed very infrequently while still maintaining maximum productivity. In terms of environmental sustainability, the rock crusher is made of metal which can have a high environmental impact, but it has no continuous emissions as a result of its use and is designed to make use of recycled materials wherever possible. 

 

The GRVLR rock crusher was created in order to improve the lives of impoverished women, in part, by increasing their income and overall economic position. When the first team attempted this project their initial business model was to have a woman save up the money to purchase a machine. Based on interviews with some women who were rock crushers, the maximum they could possibly invest in a device like this was $25. As a result, the team tried to construct a rock crusher around this budget. It was nearly impossible to construct a machine any better than a hammer on that budget. This makes sense because if there was a better option that they could afford, why wouldn’t they buy it? 

 

The current plan is to try and have the machine subsidized by the government in order to lower the purchasing cost for the women, and for the women than to pay a portion of the cost of the machine over time in a leasing program. This idea was brought to the team’s attention by Shilshila Acharya, the CEO of the team’s NGO partner in Nepal, as she knew of other social work projects that the government had assisted in paying for in the past. Because at this stage the number of machines that would be made is relatively small, the initial investment would not be extremely large as it would only be for materials and the labor of those who would be constructing the machine. The most important economic aspect is that the machine is able to significantly improve rock crushing efficiency and decrease the strain on the user’s body compared to crushing rocks with a hammer. This will not only make it easier for the women to pay a lease on the device while still paying for their needs, but will also justify it as a program worthy of investment for HCI or the local government in Nepal to invest in.

The team has realized that it is impossible to build a rock crusher that is as inexpensive as using a hammer because otherwise, the women would already be employing that method. Without having this as a guarantee, though, the team looked to reduce costs wherever possible. One idea presented itself in utilizing recycled materials. Given the high strength, abundance, and relatively low cost comparatively, steel was determined to be the best material. The team has been in contact with their Nepalese partner organization to determine the retail price of steel and see if there is easily accessible scrap steel available near the community. Another way to reduce costs that were identified was to limit the amount of maintenance necessary.

The reasons that many women turn to rock crushing in order to make money are not purely economic, there are many social barriers to women that can prevent them from being able to find work that can provide for their own basic needs and the needs of their dependents. The social issues in Nepal regarding the rights of women are not something that can be addressed by this project, but the project can provide an improvement in the quality of life for those experiencing discrimination right now and possibly provide avenues to education and job training for the women and their children. The hope is that if the women currently crushing rocks for a living are able to make more money in a smaller amount of time, they will be able to take some time off to attend training from groups like the Kopila Valley Women’s Center which give free vocational training to women. Hopefully, they can also send their children to school in order to provide them with better future employment opportunities to break the cycle of poverty.

The women work for six to seven hours each day. During that time they crush 150 to 200kg of rock. For this work, they receive $1.50 to $2.50 in compensation. The women use their own form of impact crushing through the employment of a hammer. The GRVLR device utilizes a similar method by dropping a weight on the rocks. However, the chamber of the GRVLR can hold four to six rocks at a time and crush them in the same time interval as it takes the women to crush one. From this, it can be extrapolated that the GRVLR can quadruple to hextuple the women’s daily earnings if it were to be operated in the same time frame. With this supplemented income the women could afford to keep their children in school, or they could choose to have a shorter work day and seek out the available vocational training that is available to them. One potential concern the team has is that if the device makes the labor required to make the gravel too easy that companies would buy the machines for themselves and put the women out of work. This is not a particularly large concern as the device is completely manually operated and there are large industrial machines at their disposal that are already used by some companies.

Another two important aspects of the GRVLR project are health and safety. In the context of this project, health mainly concerns ergonomics and ensuring that operating the machine does not cause any adverse health effects for the user. Safety, on the other hand, constitutes designing the rock crusher such that all possible safety risks are mitigated and ensuring that the machine follows relevant engineering safety standards. The health of the user is a major concern since crushing rocks with a hammer is extremely damaging to the joints and tendons of the target users and can cause them to develop musculoskeletal disorders (MSD). The Occupational Safety and Health Administration (OSHA) states that manual labor workers are more prone to developing MSD if they are performing actions that require excessive repetitive movements that irritate tendons and increase pressure on nerves. This includes, but is not limited to, a motion that requires increased speed or acceleration while bending or twisting.

With this information in mind, a design goal for the rock crusher is to ensure that repetitive motion is eliminated and that the user does not need to exert as much energy and force to crush the rock as one would with a hammer. Additionally, designing the rock crusher so that it can be operated in a comfortable position should also be kept into consideration to avoid poor posturing while operating the machine. The safety of the user is also important because crushing rocks can be quite dangerous and there is an increased possibility of serious injury if the machine is poorly designed. The major concerns with safety for a rock crusher have to do with rock shards flying off at impact and striking the user, or the crushing object landing on the user’s hand or another body part. 

According to OSHA standard 1910.28, the area where the crushing occurs must be completely barricaded such that no projectiles or other related objects can harm the user or pedestrians while in operation. This standard will be satisfied by ensuring in the design there are not any gaps or exposed openings where rock shards could shoot out or the user could get a body part stuck in and crushed. There is the possibility of injury due to pinching if the user were to put their hand into the place where the chain and gears mesh, but the team elected not to put guards on our prototype under the reasoning that at the speeds that the women will be pedaling there is no more risk of injury due to pinching than there is on a bicycle, which is very safe to ride without guards over the chains or sprockets. If in testing it was found that the operation made the pinching more of a threat than originally perceived, then guards would be added, but at this time it seems like an unnecessary additional cost. 

In comparing the final design to the initial goals and objectives set, in terms of ergonomics, efficiency, safety, and cost accessibility, the team has fully designed the GRVLR machine and is in line to complete the building by the start of June. The ergonomics of the machine were achieved by designing the power input to be dependent on pedal power limiting the harmful impact of repetitive motion. Efficiency was reached when the crushing chamber was designed to crush multiple rocks at once reducing the total amount of time spent crushing one rock. The safety of the machine was accomplished by completely enclosing the crushing area allowing for there to be little possibility of the user being struck by rock shards while being operated. The cost objective was delivered by having the machine easily maintainable with common materials. While the GRVLR design is finalized to the best of the team’s ability, given the extent of the virtual simulations, the team is still in the process of building and testing to confirm these results. Unfortunately, the time management for team goals did not pan out as expected due to unforeseen setbacks such as monthly changing county-wide safety regulations which eliminated the opportunity to conduct testing off-campus and weekly monitoring of local COVID cases which restricted planning and access to on-campus lab access.

The progress this team has made consists of identifying a problem, coming up with solutions, designing and running FEA on a rocks crusher in SolidWorks, building a wooden proof of concept model, and then beginning construction of a working prototype that is near completion, as well as making numerous connections made with people who have helped contribute to this project. While the team is extremely proud of these accomplishments there are also some possible next steps that an upcoming senior design team could consider if they were to take on this project. The first would obviously be testing the functionality, effectiveness, and efficiency of a working prototype. Currently, only construction towards a functional prototype has been achieved, but the finished product will not be completed in time to allow for testing. For this reason, testing needs to be conducted to obtain an analysis of the prototype. This will help gauge not only how effective the GRVLR is at crushing rocks, but also if it truly is able to help these women crush rocks at a faster rate.

Testing the rock crusher continuously, as the women would use it for hours each day, will confirm the ergonomics and ease of use of the rock crusher's power input pedal system. Additionally, testing will prove the reliability and durability of the GRVLR to operate continuously without breaking. Another possible next step would be to incorporate some sort of mechanism or design feature that improves the feeder by removing the crushed rocks from the crushing chamber. Currently, the feeder is just a simple hood on the back of the frame which has a big enough opening to let out gravel of the desired size. However, there is no actual way of removing the crushed rocks from the crushing chamber and the rocks just fall out of the hood as rocks continue to get crushed up. This is a problem because the crushing chamber could become blocked if too many rocks get crushed and not enough rocks exit out of the hood of the filter. 

 

The next step for the next design team would be to implement some kind of mechanism that removes rocks from the crushing chamber. This could be a sweeper-type mechanism that is connected to the hood of the filter and allows the user to sweep gravel off the crushing plate and out of the hood. Another possible idea would be building a mechanism that tilts the crushing plate so that the gravel falls off the plate and out the hood. One last next step that has been considered is conducting Nepalese sourcing for local materials in Birendranagar, Nepal. This is a part of the project that was not able to be completed due to COVID-19 complications that made it difficult to communicate with connections in Nepal and get information about available materials in the area. This is something that the next senior design team would want to do since the machine will need to be made of parts available in Nepal as well as built and manufactured in Nepal. Once that is done an additional step would be to get in contact with a machinist or welder in Nepal in order to start thinking about a manufacturing plant.

 

Over the course of this year, the team has had to adapt to many changing circumstances, change their working habits and learn some new tricks, this taught the team a lot of lessons, mostly in the areas of team and construction management. The team learned a great deal about how to crush rocks, as earlier described, but the additional advice that the team would like to pass on to the others or a team taking on this project is described below. In the area of team management, the team learned a great deal from the specific circumstances of our project and from the things each team faces every year. The team learned a lot about the challenges of an international project. While it can be difficult to adjust to a different culture and schedule international calls, communication is the most difficult thing. In order to keep everyone on the same page, there needs to be frequent, responsive, and scheduled communication or there will be massive delays to your project based on waiting for communication or miscommunications. In addition to managing communication with partners abroad, the team had to manage itself, and its own goals.

Three things that the team learned are first, having many small self-imposed deadlines or check-ins to keep a constant healthy working pace rather than infrequent sprints. Second, even if team members are working on completely independent tasks, working in the same room or on zoom together can help productivity and communication, especially in the midst of a pandemic where team members do not see each other for other purposes. Finally, the team learned to be prepared to change plans at a moment’s notice. Over the course of the year, the team faced many sudden challenges and changes in scope and had to readjust goals and plans. If the team was not this flexible they would have not been able to move the project forward for months of the year. There are also some things that the team learned from the intensive building that has been performed over the past quarter. The first thing is that there are no steps that can be saved for later. Eventually, you have to drill holes and choose bolts and nuts for every part, if you save it for later it will only make things sloppy and difficult down the road so do it in the CAD stage. Another important lesson is that every single part needs a manufacturing plan and that the manufacturing plan should be converted to a manufacturing task list so that you can perform manufacturing tasks in a timely manner. Many things that look beautiful in CAD are not easily manufactured or even manufacturable at all with the facilities on hand.