Portal is a virtual reality, museum installation consisting of a moving display and a 3D world. Through head tracking, the display can be moved and the perspective from which the world is rendered can be altered to provide a single-user the experience of peering through a portal into a different world. The gantry that moves the display will be ~8 feet tall with the ability to coarsly follow a user's gaze as they walk around. While the user walks around the display, the scene displayed will also move to provide fine-adjustments and the impression of looking through a window. The current plan for the design of the gantry is to use a chain system to move the display. On the base of the arm there would be a motor that turns the direction that the arc looks in. The 3D worlds are being designed with Unity.
Getting to and from the train is not an enjoyable experience. Train stops are not always conveniently located, scooters are not a practical transporter as it is hard to fit a scooter in your bag, and bikes are not allowed on trains forcing riders to risk having their bike be stolen. So, we set out to create an enhancement to the T riding experience that was fast, compactable, and lighter than the existing ways of getting to and from the train. From the beginning, we intended to create a device to enhance the T, what we believe is an already existing and functioning mode of transportation. We had no intentions of creating a device to replace the T riding experience. With this in mind, we set out to design the Transit Wheel.
We started the fabrication process by water jetting the wheel side and wing. This was good and bad. We found a lot of little problems that we had to fix, it helped us find problems in our design and fix them. It was bad because the wheel side and win that we cut are not perfect. We then started to design for fabrication. The wheel halves were hard to fabricate due to undercuts and poor designing. We simplified the design and changed both halves to be symmetrical. We also changed the right wheel mount. It was previously too big and wasted material. We refined the design to make it smaller and cleaner.
There are many different electronics elements in Transit Wheel. To connect them we have the main PCB. The PCB holds the Arduino, two analog to digital converts, a gyroscope, an accelerometer, a compass, two level shifters and voltage monitor. This allows us to manage all the sensor on transit wheel in a compact way.
To measure the amount of forward or backward lean that the user provides, we have pressure pads on the wings. We spent a lot of time looking at sensors but could not find one that was long enough for our purposes. We decided to make the sensors ourselves. We are using velostat, a material that is more resistive the more pressure put on it. We will have strips of that glued to a flexible PCB with the other surface touching the metal of the wing. This will allow us to measure the placement of the person's weight to see how much they are leaning.
The gears had to be held in place using two gear mounts, one on either side. The Planetary gear set has two layers of three gears. The Gears have bearings that ride on three rods. The two gear box halves have to be attached somehow. We had to add three extra rods to hold the gearbox halves together. We can't put screws through the gear shafts because the process of drilling and tapping them would make the shafts bulge and not be as precise as we need them. The gearbox is attached to both wheel sides. This is for two reasons. First, the gearbox will align the wheel halves, it also disperses the force evenly along the two wheel sides.
Getting to and from the train is not an enjoyable experience. Train stops are not always conveniently located, scooters are not a practical transporter as it is hard to fit a scooter in your bag, and bikes are not allowed on trains forcing riders to risk having their bike be stolen. So, we set out to create an enhancement to the T riding experience that was fast, compactable, and lighter than the existing ways of getting to and from the train. From the beginning, we intended to create a device to enhance the T, what we believe is an already existing and functioning mode of transportation. We had no intentions of creating a device to replace the T riding experience. With this in mind, we set out to design the Transit-Wheel.
In the preceding two weeks, we spent the bulk of the time designing the outer shell of the transit wheel and searching for a motor, during this two weeks we started designing the wheel, but also incorporated feedback and returned to heavily modified the body design
We spent a lot of time redesigning the body of Transit Wheel. It used to have a rounded top with organic looking curves on the wings that met to make a handle. We had a design review at SPI. We talked about a lot of things, like the wing lock and the body design. The engineers there told us that the wings and wheel cover would be difficult to make and very expensive. We decided that that wasn't realistic to fabricate so we shifted approach. Now the wheel cover has three edges on the top to make a trapezoidal shape. The wings match the shape of the wheel side, and when they are folded up all the edges meet. The edges on the wings are folded up to increase the strength of the metal. Since the handle is no longer attached to the wings, it's fastened to the wheel cover.We also decided to use steel instead of titanium because of money, steel is also a lot easier to work with. When we went to SPI we talked a lot about the wing lock, many ideas were talked about, but we decided that just screws are the mode reasonable approach due to time.
When we started working on the wheel we had to think about a couple of things. First, we had to figure out how to reduce friction when it turned. The most obvious way to do this was bearings, the problem is that bearings that are as large as we need are either too expensive or don't exist. The next problem was fastening the two wheel halves together. If we used screws the two halves could move slightly and get out of aligned. We decided that using screws and a small locking mechanism on the edges where the wheels meet.
A critical aspect of the wheel design are the gears, which transfer and amplify the torque from the motor to the wheel. Since our gears need to fit inside the wheel, with the motor, we decided to use a planetary gear system. Planetary gears are known to be suitable for high-torque, compact applications. The struggle with gear design started with finding suitable software in which to design them.
I tried multiple different software to design the gears I started using gear generator. I stopped using that because it does not make accurate teeth and there is no good way to import them because it uses polylines instead of curves. I started looking at Solidworks add-on for gear generation that got good reviews. I found a software called Eassistant through this site calling the best gear generation tool. I found out after doing more research than I should have had to that Eassistant does not do gear generation. In the past I had used the Solidworks toolbox I knew that they had gear model but did not think they were customizable I found through a video that you can customize the pitch multiplier and tooth count. Getting the proper gear ratio was challenging I thought we would need a much larger ratio to get enough torque. I made a 3 layer planetary gear set with 2 caked gears stacked and an annular this took a long time to get to this solution. When David and I calculated the gear ratio we realized that we only needed a 2 layer gear set with one set of planets and annular gear.
The breath sensing flower went through a complete design overhaul over the past two weeks. For the first week of the studio we worked refine the existing design of the flower. As we did this we were also working on getting the opening mechanism working. We recreated the flower base to make the flower easier to open. The base was split into two snap together parts in order to make it easy to 3d print, and the bottom piece was made larger to allow the strings from the flower to come down at a less steep angle. The new flower base helped with the ease of opening the flower a little bit, but it was still fairly hard to pull the strings. In order to open the flower we designed a crank mechanism that would pull the flower strings down as it turns. We soon realized that for this mechanism to work the strings would need to be easy to pull. If they were not then the crank would either break or not move at all. When created We designed and 3d printed a stem for the flower with a small hole in it to which the crank would be attached. We also made a second piece of the stem to add two holes close together in order for the flower strings to come out of the stem right above the crank. This method seemed to work fairly well, but it was hard to turn the handle.
During the second week we got the humidity sensor to work for detecting breath, and we came up with a better design for the flower opening mechanism. We linked Arduino and Processing so that the humidity and temperature sensor values could be read by Processing, and then used them to influence the sizes of two colored circles on screen. While the sensors may not be the most sensitive, we will be combining them with code to separate peoples breathing rates from the noise around them. Since the string and crank method we were using was hard to implement and use, we decided to start experimenting with a much simpler design. The new mechanism utilizes a pulley mechanism that will reduce the number of parts that we use. Instead of using springs, strings, and a crank, the new mechanism will just have a stem with a locking slider that pulls the flower petals down. The petals will be attached to the sliding ring using a stiff part instead of strings, allowing the slider to both open and close the flower. Throughout the next two weeks we will continue working on this new design in order to make a full model, and possibly even the final iteration before production.
Throughout our second Grove studio we focused on choosing a final leaf pattern and design. We started out trying to modify our simple cupped leaf design. We had only cut them out with scissors so far, so we started designing them in rhino. We had to pay attention to the shape, pattern, and how the leaf will hold together. Working with the idea that the trees are an extension of the body, we also worked on making the leaves with lung patterns. While designing the leaves, we took pictures of lungs and traced them in rhino. We altered the trace to make the shapes more abstract, and then started cutting different versions of it.
After designing a few lungs, we decided to start layering the lung pieces to make them have more volume. The first pair we designed was a lung with a layer of veins running through it. We used the lung pattern we had designed the day before and traced out the veins to layer it. This design worked well because it made the lung look more lifelike, but it was hard to tell where the different layers started and ended.
After we had worked on the patterns, we started looking at shape and arrangement. We came up with a few ideas that we liked, but decided to start with having many long and thin leaves fan out from the branch. We took our lung design from the day before and started stretching it out to make it look more like a leaf. After making it longer, we had to start looking at the rim design. we had a lot of trouble making it because we didn’t know exactly how we wanted it to look, but we finally settled on a very abstract and organic curvy edge. This design comes with many complications. We have to make sure that the attachment is flexible so that the leaves sway and can move around, but we also have to make sure that they will not be destroyed by the wind.
For the rest of the studio, we worked on making a small Grove. The point of this was to make 10-15 tiny Grove trees and figure out how they can be arranged and design. We started by making all of the bases for the trees. The bases we made varied in height and size. We decided that each tree would have one thick trunk and six small branches. These were attached by holed in the base that they could stick into. The one thick trunk took a place in the middle of the base and the six thinner branches stuck into the base around it. The branches wrapped around the trunk on their way up to the top where they fanned out.
For the past six weeks we have been working on Grove, an interactive forest that will be at Burning Man 2016. Last studio, we made a Grasshopper file that generates leaves for the trees. We also came up with the idea for a stacked plywood platform for the trees, and designed a flower that will open up to reveal a breath sensor.
This studio, we did a complete redesign of the breath sensing flower. The new design is much simpler to make and use. The petals of the flower uncurl to reveal the sensors while looking like a more natural flower.
We began by designing the petals of the flower. The new petals have a more simple frame that consists of just a single piece that goes down the middle of the petal shell. The shell of the flower now acts as the hinge of the flower, reducing the amount of complex parts needed to construct the flower.
As we designed the opening mechanism we started out by making a base and a center pin. The base of the flower cupped the petals and had slots for the ends of each petal to fit into.The pin is designed so that when the user pulls the flower down the pin will stay put, pulling the ends of the petal frames up with it. The first center pin had eye hooks coming out from its sides, which we soon learned stopped the flower from opening and closing correctly.
The second mechanism consisted of a larger base and an inset center pin with eye hooks on top. The base was made larger in order to fit an inner layer of petals, but we later decided not to use these. The eye hooks for the center pin were moved to the top so that when we inset it into the base they would still be accessible. We ended up removing some of the screws holding the petal frame to the shell because it allowed the petals to curl like a real flower petal.
The final flower for this studio has a slimmer, more natural base and a center pin that connects directly to the petal frames. We got removed the inner petal slots on the base, allowing us to make it smaller. We also chose to give the base a more cone like shape so that it would match the design of the rest of the flower. We removed even more parts from the flower by attaching the petal frames directly to the center pin. Instead of having eye hooks, the center pin now has slots for the petal frames.
Over the next two weeks we will shrink the flower petals, as well as adding the sensors and a locking mechanism to hold it closed when not in use.
During this studio we redesigned the breath sensing flower to make it smaller and more manageable to hold while in use. The first iteration of the this studio’s flower had small petals that did not poke people in the face while they have the flower close to their face. In order for the smaller flower to close we had to redesign the center pin that connects to the petal frames. We moved the attachment points for the petals frames out closer to the petals, but this version of the flower was still not able to close completely.
For the second iteration of the flower we modified the center pin to allow the flower to close, and we also added a locking mechanism to hold the flower open or closed. We moved the attachment points on the center pin down and in towards its center. This helped the flower to close but the petal frames hit each other, causing some of the petals to overlap. The locking mechanism that we added to the flower is very simple. The center pin had two small divots in it, and the flower base had a spring loaded ball in it. As the center pin is pushed up or down, the ball snaps into the divot. The center pin can then be pushed passed the ball easily.
The third iteration of the flower added fillets to the pieces, as well as a cone to direct breath towards the breath sensor. For this iteration, we refined the design of the flower by adding fillets to the base and center pin. These help make the pieces stronger so that they will not break as easily in the wind. The cone that we created snaps onto the top of the center pin, and has space for the breath sensor to sit at the bottom. It directs peoples’ breath down to the sensor, and it also reduces noise that would be picked up by the sensor otherwise.
The current flower now has lighting, a transparent cone, and tapered petal frames. We added lighting to the flower by placing an LED upside-down in the breath cone. In order for the light to diffuse evenly throughout the entire flower, we printed the breath cone out of transparent filament. This not only allows light to pass through, but it glows when the flower is open. To make the flower close completely, we made the tops of the petal frames thinner so that they would not hit each other and cause the petals to overlap.
The wheelchair is one of the best inventions to help disabled people. It can easily transport people from one place to another safely without having to use a person's feet as a means of transportation. However, people in wheelchairs are extremely limited in a number of activities they can do. They can't go certain places, they can't reach certain things, and most importantly the interaction is not quite the same. For kids, one might feel included as they are unable to play on the carpet with the other students. Juan an elementary school student expressed these problems to us and felt he needed a solution to solve his problems. The uplift wheelchair is a regularly sized wheelchair that has the capabilities to lower and expand fully outwards to the ground.
This second version of the Uplift wheelchair uses a suspension and gear system to lower the chair to the ground. In an upright position the wheelchair looks identical to a normal wheelchair, however when unlatched from the back, the chair can be slowly lowered to the ground. For support, there are two beams attached to the base and wheels. The beams bear the weight of the user and multiple springs assist the chair, resulting the a smooth lowering motion. In order to support the full weight of Juan, the wheelchair also needed support in front so it didn't tip over. This is why gears were added attached to the parallel beams. I had to do a lot of experimenting with the placement of the beams to that the chair clears the wheels, but in the end this position was chosen because of the front beams. I knew that these wanted to be able to expand with the chair making the center of mass always be over the wheels, but I didn't know how to fix them in place. The whole point of the gears is for the front beams to actually bear weight depending on the suspension speed in the springs. Once lowered to the ground these beams would support Juan's feet and keep him in a relaxed position. To go back into his locked position a helper or teacher would simply push on the back of the wheelchair with his or her foot on a pedal and with a certain amount of force, the chair would raise back up. While this would need a huge amount of force, the springs would add enough tension and pressure to make this "release system" easy to engage and disengage. Once in upright position the springs would relax and to keep the chair from falling, a door lock mechanism would be placed on the chair to lock the seat in place with a click. This would be the only mechanism needed to engage and disengage the chair.
While a lowering and raising wheelchair is already out on the market, our wheelchair would have significant advantages over them. Firstly, the price range of an automated scissor lift chair is between 15,000 and 30,000 dollars. Most disabled have income problems as most cannot work and so this wheelchair is way out of their range. Our chair would be a few hundred dollars, and as most of the cost is the chair itself with all of the padding. Our chair would just come with a base and with a few bolts, one could take their fully functional chair and attach it to our base while still using their wheels and expensive parts. This wheelchair would be useful to all kids and adults who wish to be included in activities that they should be able to participate in but can't, due to their disabilities.
In this studio, continuing NuVu students will be challenged to advance their skills through a term long project. Students will work on larger teams that will stretch their collaboration. They will need to learn and practice time management skills. They will be asked to explore the requirements of a project, some of which may come from customers. They will be given more time to explore alternatives, choose amongst them, and justify their decisions. And, they will also hone old skills and develop new ones, ranging from CAD to fabrication to programming and circuit design. Proposed projects include: a large-scale art exhibit at Burning Man, a portable Segway-like personal transportation device, a moving virtual reality portal, and a lifting wheelchair attachment for children with Cerebral Palsy.