Modeling a children’s motorcycle Assignment DG619 - Prototyping (3D) and Model Making
Jelmer de Maat
Assignment DG619 - Prototyping (3D) and Model Making Teacher: Arjan Steketee
Jelmer de Maat / B2.2 Industrial Design / s099450 June 2011
In this report the process of designing and making a model of a children’s toy is described, as well as several other activities that have taken place in this assignment. In the end a vision on the future of model making is given.
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Paper exercise The prototyping started with paper modeling: making the strongest bridge possible from only paper sheets, tape and glue, while using as less of these materials as possible. I worked together with Samantha on this particular assignment. Together we made a bridge base from rolled paper sheets that formed a pyramid construction. The rolled cylinders rested on each other by making use of incisions in the corners of the cylinders, which prevented us from using more tapes. The bridge part itself was made out of triangular (alternately) folder paper sheets with a top and a bottom paper sheet to keep them in place. This bridge part was placed inside the pyramid construction. We used little material (12 sheets of paper, 15 pieces of tape and no glue at all) to score as high as possible on the “bridge ranking”, but unfortunately the bridge turned out to be not sturdy at all. It didn’t hold one plastic bottle that was filled with water for one fourth of the volume. The connection points in the pyramid construction appeared to be too fragile. Next to this I did the egg crash test: making a paper model that could catch an egg, released high above the ground, and prevent it from breaking. I made a construction that consisted of rolled paper sheets only. From bottom to top, the sheets started rolled up small and sturdy, and ended
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rolled up large and flexible. One sheet of paper was used as a bottom plate. The reason for this construction was the flexibility of large paper rolls, and the transition to small rolls that provides sort of a shock absorber. This construction proved to work very well: not matter how high I would let go of the egg, every time it remained intact. A video of this egg crash test can be found here: http://vimeo.com/24563619.
Clay exercise In the clay exercise I chose to make a model of my mobile phone. Actually the model wasn’t based on my phone but on my iPod, since that form is way more interesting than that of my phone. The hardest parts about modeling the clay were to get the right angles and bends, and getting the form symmetric across at least two axes. The iPod shape doesn’t seem hard to make, but it was difficult to get straight lines and flat surfaces with clay: every little (accidental) touch reshapes the clay. I see that this means you can work very precisely with clay, creating difficult complex shapes, while on the other hand creating clean straight surfaces can be more difficult. I found that clay in general was nice to work with: it gave me freedom of form and a low threshold to easily create complex shapes.
The construction of the paper bridge
Testing the strength of the bridge
Excursion Hoogerdijk Technical Rubber
niques that are involved in rapid prototyping are based on the same principle: building products via the selective addition of material based on 3D files made on the computer. I think the essence of these techniques is the speed, the detail of production and the reproducibility of products and parts. A toy car like the one we saw at the presentation, completely running on many little rotating gears, can be produced in one go. No need to assemble a product: the product parts can be produced and assembled at the same time.
At Hoogerdijk Technical Rubber all kinds of rubber and plastic solutions are made, mainly as parts to implement in other products. Various types of soft foams and hard plastics are present and they can be used together to create a special combination (a soft rubber and a hard cover layer for example, or a thin rubber with a sticky tape layer). All these materials can be very useful in physical product designs: products that are handheld may need soft covers for a pleasant grip, or transport designs may need such materials for seats. A children’s playground uses all kinds of hard and soft plastic to both offer stability and safety. I see possibilities here for my future designs, and I will certainly keep a production company like Hoogerdijk Technical Rubber in mind when thinking about material solutions.
Excursion TNO The Rapid Manufacturing department of the TNO in Eindhoven is a professional quick prototyping environment that makes use of the latest technologies such as 3D printing. They work together with both students and companies. All the tech-
Different techniques that we saw at the TNO have different advantages and disadvantages. They differ in the approach of production, the material choice and costs, and a combination of these factors must be taken into account when deciding on which system to use. A good example is SLS – Selective Laser Sintering. This technique makes use of a platform with powder on top, and a laser that draws a shape in the powder from above. Then, the platform is moved down just slightly, and new powder is spread smoothly on top. Then the next layer of the product is sketched on top, and the process repeats itself
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again and again. This way a product is build up in layers. Other techniques work according to the same principle. A difference with for example Fused Deposition Modeling (FDM) is that SLS uses a laser that shapes the product, and FDM uses an extrusion head that supplies material from a cartridge. Again the platform on which the product is build moves down each time another layer is started. With FDM however there is no support powder in places where a shape overlaps air, or bends outwards. Therefore support material is supplied next to the build material to provide support for
an innovation driven education (and profession) I think it is strange that our education provides little opportunities and support for Rapid Prototyping. We should be the early adopters and embrace such technologies.
instable parts. Another technique is SLA – Stereo Lithography, which is very similar to SLS, only this time a liquid is used as a building material. In a vat with the liquid the building platform moves down while a laser melts layers of the product in the liquid. An advantage of SLA is that very small parts can be made (several millimeters or less). With all these techniques it is necessary to remove the support material afterwards: sometimes special liquid is needed for this process. With Rapid Prototyping, very complex products and parts can easily be produced, also in larger quantities. Products with working functionalities can be produced right out of the machine. And, very tiny parts can be produced with great accuracy. It’s exciting technology, and I expect to use it in the future to make sophisticated prototypes. It’s my goal to at least test a rapid prototyping technology during my bachelor here at ID. I especially liked the open source 3D printer project, and I would like to see those integrated into our education soon. Since industrial design is
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Mood board of existing motorcycles for children
Making a children’s toy
As main project I chose to design and build the children’s toy, a multifunctional new toy that integrates two existing products in one: a toy car and a vacuum cleaner. The idea here was that while a kid would drive around in the house, the floor would be cleaned. The goal was of course to make a good looking, 1:1 form prototype using materials like wood and foam. This project seemed way more interesting for me than the other project, where one would make a steering wheel handheld design for disabled people. I have far more affinity with the user group of children since I have experience in working with them (as a trainer) outside the world of design. I see it as an identification and consolidation of my vision and identity as a designer to make such a product: one that is helpful, functional and fun for kids, thus helping two types of users (the parents and the children).
Analysis, Idea generation & Concept development The idea of a riding toy for children immediately brought me the impression of a real transport vehicle, only then sized down to make it an extra small but realistic vehicle for children. It would be very nice to have a toy that looked very real and cool, giving the impression of a real vehicle so
children would feel proud of their “toy”. With that thought in mind I started thinking about possible shapes. First I started sketching possible forms. I went from cranes to airplanes and from rockets to motorcycles. The crane and the airplane seemed not safe enough because of the large parts they would have outside of the vehicle (the arm of the crane and the wings of the plane). These parts could easily damage the house or create unsafe situations for children. That’s how I came to the rocket, since it has no wings. Still, a rocket without any additional parts at was a cylinder and looked way too little exciting for me. I added small wings to make the de sign more interesting, but it still gave an unsafe feeling. Thinking of other possible “cool” vehicles with which a kid could show off to his friends, I thought of a motorcycle. A motorcycle has just the right image for this children’s ride: a sign of freedom and a “rebellious” character, a special and personal item to the owner, but also enjoyable in groups. The motorcycle would be the perfect idea. I created a mood board which showed an analysis of various motorcycle toys and bikes that are created for children. Next to that I looked at images of real motorcycles to get a feeling of how
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they were designed. Sketching existing and new designs of motorcycles I tried to make a simple yet compelling design. The design had to have the “cool” feeling and be simple in its construction. It had to be as real as possible, and therefore all sketches were based on two-wheel motorcycles, while in reality I knew that a children’s ride would need three wheels to keep it stable.
sometimes to improve it and sometimes to account for production possibilities. The final design consist of a straightforward, sturdy front fork, a fluid connection to the driving wheel (which needs to be doubled, to exist on both sides of the two back wheels), and one thin and fluid seating surface that runs from the front fork all the way to the end of the rear fender.
Keeping all these details in mind, I created a basic form that consisted out of only three parts: a steering/fork part, a connection to the driving wheel, and a seating that goes over into the rear fender in one fluid line. Actually all parts consist
As the motorcycle needed to be as real as possible, I chose for an existing and well known solution to attach the front fork to the chassis. With two simple connection parts and one center axis it is possible to attach the chassis with one hole
out of fluid lines: nice fluid curves in the material that form the basic character of the motorcycle. This simple but elegant solution was right according to my ideas of a cool feeling and simple design. The basic shape did change a few times:
to the two main tubes of the front fork. Details like such connections, and like the bended steering wheel, finish the design to make it stand out. The motor has a friendly, yet strong look that (hopefully) is very appealing for children.
First sketches of children’s rides
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Development of the motorcycle
Final design sketch
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Creating the model As can be seen on the mood board, many of these children’s motorcycle rides are made from wood. To me, this was also a first choice since it has many advantages. Next to the friendly but sturdy look of wood, it is also easy to process. While my model does have complex bended parts, it is still certainly not undoable with wood. Wood is also friendly for kids: nicely sanded wood removes sharp edges, and wood is relatively soft when compared to metals or plastics. Of course wood can be recycled easily which makes it more nature friendly. And moreover the wood gives the design the feeling it needs: simple, yet compelling. The building process started with the parts expected to be the hardest: the bending of wood. To get the fluid wooden lines in the design I needed to find a solution to create a bended piece of wood that was still sturdy enough to carry a three year old kid, at least. Together with the assignment teacher and a car model making expert some options were explored. One option is to first steam a plate of wood until it gets flexible, then bring it into shape, and then let it dry. This option would have needed some exploration as it may not end up perfect after the first try. Also, multiple plates of wood together might work better than just one. It would give a nice smooth surface though, something that would less easily be achieved by the second technique: cutting a lot of curve-shaped lines out of a thick piece of wood and glue those together, horizontally one after each another. This would give the perfect curve, but the process takes longer and the end result may not be as satisfying as a “real” piece of curved wood. How I managed to do it in the end
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is using a third technique: several layers of thin, bendable wood are put into shape at the same time, while they are glued together. A simple mold that has the right curve is used to press the layers of wood very strongly together. When the glue is dry, the layers of wood stay go together in the bended shape. This way the bended seating part of the frame was created. Due to time restrictions I wasn’t able to make all the wooden bended parts: two of the sustaining parts of the chassis are not bend in the way I want. They do show the curve in the vertical direction, which prevent the lacking bend a bit from being quickly noticed. I chose to bend the top surface since that was the eyecatching and most important part for the character of the design. As said, the two sustaining parts of the chassis are connected to the back wheel(s) via the back wheel axis, which is made out of aluminum. This axis is set up, as is always the case (and necessary for the driving wheels to move straight), perpendicular to the direction of the motor. Since the two sustaining chassis parts are set up under an angle to come together in one point at the turning axis of the front fork, the holes for the rear axis needed to be drilled under an angle as well. When these two sustaining parts would actually have been bend, the rear parts could have run straight and this wouldn’t have been necessary. The two rear wheels are fixed in place on the axis by drilling holes next to their position in the axis and putting some blocking material in these holes. Just like both the rear and front axis, the front fork is made out of aluminum cylinders. I chose
Plywood glued into its bended shape
this material for its nice matte finish, the lightness and the ease of production. Aluminum totally fits with the design of the motorcycle. The design of the front fork is simple but realistic: two staves, with the front axis in between, that hold the front wheel, the connection parts to the chassis above the wheel, and the handlebars attached to the top of the fork with an almost invisible connection. The front wheel is kept in place with blocking material just like the rear wheels. The front axis runs straight through the front fork bars, in which holes are drilled for both the axis and (perpendicular) the mounting bolts. The mounting of the handlebars was a difficult point, since inside of the aluminum cylinders there is no material to fix the handlebars to. Eventually the solution to this was to create this material: a wooden stave was sanded just
enough until it fitted precisely inside the aluminum cylinder. In this wood a little hole is made for a nut to be glued in, after which a bolt can be screwed in through a hole in the steering tube. This aluminum steering cylinder is again bend for both the aesthetic value, and for the child to be able to reach the handlebars. These handlebars are made from wood, sanded into a rounded and comfortable shape. The mounting of the front fork to the chassis was easier than it seemed. My system that I copied from real motorcycles worked perfectly on this smaller scale: two pieces of support wood are held by the two aluminum tubes of the fork. In the middle of these top and bottom support pieces two holes are drilled to hold the steering axis. Around this axis a piece of wood is shaped that is connected to the chassis. This wood is
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shaped is such a way that it seamlessly connects to the two support parts of the chassis. Lastly, the seating part had to be connected to the frame. This is done using a small piece of connection wood in between the two support pieces of the chassis. This connection piece is the only point of connection between the seat and the frame: simple yet solid. It also allows for the seating to have a natural suspension property. In the front the seat plate slightly hovers the chassis connection to allow for a larger steering angle. In the back the seat plate hovers over the back wheels freely. After all the parts were produced, some sand-
ing was done on all the wooden parts to finalize them, and minor corrections were executed to tweak the bike into its last and best state. During the making of the model I continuously kept the qualities of the design in mind. I had to find solutions for connections of parts very often, and I made decisions mainly based on the aesthetic value and the physical quality of the solution. The design had to be simple yet cool, and so no complicated parts or connection can be seen on the outside of the model. A bolt and a nut is the most you can discover as a connection unit, nothing more than that. This is part of the beauty of the design: you can see the “inner workings�, and there is no need to try and cover
A motorcycle coming together
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The eventual suspension of the seat (middle piece)
these since their aesthetics are part of the design. I think this gives the design an intuitive and solid feeling. Extra pictures can be found here: http://flic.kr/s/aHsjuLBvL2.
The front fork and iits connections
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Reflection / Future of model making The introduction of this assignment was to work with paper and clay. I experimented with these materials to create bridges and clay models of my phone. Though we spent little time on these assignments I think it was a good introduction to the assignment to get a feeling for material. Especially the clay modeling seems to me important, as I can relate it better to product design than the paper experiments. I never worked with clay before to create models, but I liked the creativity that you can put into the clay forms. It was difficult to work with when making smooth surfaces, but it’s more important that it gives a lot of room for experimentation. When designing a handheld object, for example, many explorations can be done to design a comfortable object. I will use clay more often from now on, especially when designing smaller (handheld) products. Designing and building the children’s motorcycle gave me new knowledge and new skills. Especially during the concept development I noticed that I picked up a lot from sketching out ideas. It was very helpful to have some example images of real motorcycles as a basis, and look at existing products for children to catch up on what’s already on the market. I took specific parts from all the examples and made new sketches with combinations of these aspects. Sometimes I completely dumped an idea when it didn’t satisfy
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me eventually. The process to the final design was quite long, but when I look back I see that it was worth it. I went from one design to another, and I really feel like the final design was indeed the best. It was hard to separate the good from the bad when it came to specific design details: sometimes I would have liked to implement more things or tried out several options first. But I chose one design and completely focused on getting that one done as good as possible, also due to time restrictions. Through I am really satisfied with the result, some things could have been improved. For example multiple parts of the frame should have been bent (and not only the seat plate). Next to that the wooden parts I used to connect the frame to the fork could have been improved. These and other parts of the bike didn’t use the same wood, so the color difference was quite big. The color of the total bike would have been the color of the seating plate, the color of the sanded plywood: a light and clear wood color. This color combines great with the clear matte grey of the aluminum. I would also have liked to put custom tires on the bike. The tires used in the current model are the most suitable tires I could find in hardware stores nearby, but they were quite general. The real wheels should have had real metallic rims and
black tires filled with air instead of plastic. Though the ones I used now aren’t bad, this would really have improved the look of the motorcycle. What I learned from building the motorcycle are mainly producing techniques and experience in working with wood and metal. I learned for example several methods of creating bended wooden parts, and I learned about the properties of aluminum and how you can process this metal. I didn’t know aluminum was so easily to process, for example with regular drills and saws. I’m sure I’ll try out more with this material in future projects. Next to that I had to be creative in finding the right materials in the right places. In fact the workshop in Vertigo has very limited possibilities in materials, but I only realized this with this assignment. Having built many prototypes there in the past I have now seen and tried out most of what is possible in Vertigo, and now I realized that I want to experiment with custom materials, to make more specialized prototypes. Next to that it would be good to try out new techniques that aren’t available in Vertigo, like milling 3D printing. This Rapid Manufacturing we have seen at the TNO was very interesting. There are so many possibilities with all the different techniques and so many things can be created in great detail. It was exciting to see what can be done: complex shapes, working mechanics, home-made opensource 3D printers for “just” 1000 euro’s… This technology is going to be a standard in our world some time. Being able to manufacture a design from behind a computer with a 3D file is nowadays a possibility for students to create a finetuned prototype, but in the future it will also be
available for home users that want to print a new part for a broken vacuum cleaner. As said, I think that we as Industrial Design at the TU/e should be handling these techniques with a far more progressive approach. Set up plans, projects, maybe themes that focus on such technology. As an innovative faculty there need to be innovative techniques widely available for all students. Of course, while these rapid prototyping techniques are great, I think they are not going to replace traditional, physical hand modeling. Just like traditional newspapers will exist next to the iPad. Designers and companies just need to find the right approach to bring these two sides of design together in a good way: the one does not have to exclude the other. Things like clay modeling and sketching are necessary to be creative and explore possibilities. Computers are way too constraining in that sense: at least you can make creative mistakes and take side-routes when you are freely designing with your hands. Finding the balance between these two fields is maybe going to take a long time, but I think hand modeling and rapid prototyping will both find their place more or less automatically. Real designers will know what to use when. Maybe some time in the future, hand modeling and rapid prototyping will even be integrated and fall under one and the same name… but that’s just speculations. As a last remark I would like to advice the assignment teacher to provide more guidance when it comes to getting a feeling for materials. We only shortly addressed paper and clay modeling, and then went over to a final prototype quickly. It would have been interesting to see for example more use cases and best practices about
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working with clay: maybe one or two days could entirely be dedicated to creating forms with clay? More time would then be spent on (making) specific forms and shapes. Then, the core of the assignment would be addressed more: getting a feeling for materials and model making. This would also improve the thinking about forms and shapes in general, to get a better understanding of aesthetics and beauty as a whole.
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