Modeling a children’s motorcycleAssignment 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 assign-ment. In the end a vision on the future of model making is given.

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Paper exerciseThe 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. To-

gether 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 construc-

tion appeared to be too fragile.

Next to this I did the egg crash test: making a pa-

per model that could catch an egg, released high

above the ground, and prevent it from breaking. I

made a construction that consisted of rolled pa-

per sheets only. From bottom to top, the sheets

started rolled up small and sturdy, and ended

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 exerciseIn 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.

Base

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Excursion Hoogerdijk Technical RubberAt Hoogerdijk Technical Rubber all kinds of rub-

ber and plastic solutions are made, mainly as

parts to implement in other products. Various

types of soft foams and hard plastics are pres-

ent 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 pleas-

ant 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 produc-

tion company like Hoogerdijk Technical Rubber in

mind when thinking about material solutions.

Excursion TNOThe Rapid Manufacturing department of the TNO

in Eindhoven is a professional quick prototyping

environment that makes use of the latest tech-

nologies such as 3D printing. They work together

with both students and companies. All the tech-

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.

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 decid-

ing 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

The construction of the paper bridge Testing the strength of the bridge

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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.

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 extru-

sion 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

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 ac-

curacy. It’s exciting technology, and I expect to

use it in the future to make sophisticated pro-

totypes. It’s my goal to at least test a rapid pro-

totyping 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

Mood board of existing motorcycles for children

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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 peo-

ple. 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 develop-mentThe 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 with-

out 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 enjoy-

able in groups. The motorcycle would be the

perfect idea.

I created a mood board which showed an analy-

sis 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

Making a children’s toy

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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 construc-

tion. It had to be as real as possible, and there-

fore all sketches were based on two-wheel mo-

torcycles, while in reality I knew that a children’s

ride would need three wheels to keep it stable.

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

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 ac-

cording to my ideas of a cool feeling and simple

design. The basic shape did change a few times:

sometimes to improve it and sometimes to ac-

count 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.

As the motorcycle needed to be as real as possi-

ble, I chose for an existing and well known solu-

tion 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

to the two main tubes of the front fork. Details

like such connections, and like the bended steer-

ing 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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Final design sketch

Development of the motorcycle

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Creating the modelAs 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 rela-

tively 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: sim-

ple, yet compelling.

The building process started with the parts ex-

pected 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 flex-

ible, then bring it into shape, and then let it dry.

This option would have needed some explora-

tion 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

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 lack-

ing bend a bit from being quickly noticed. I chose

to bend the top surface since that was the eye-

catching and most important part for the charac-

ter 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 nec-

essary 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

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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 connec-

tion. The front wheel is kept in place with block-

ing 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 (per-

pendicular) the mounting bolts.

The mounting of the handlebars was a dif-

ficult point, since inside of the aluminum cylin-

ders 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

Plywood glued into its bended shape

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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 prop-

erty. 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 of-

ten, 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 connec-

tion 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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these since their aesthetics are part of the de-

sign. 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

The eventual suspension

of the seat (middle piece)

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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 im-

portant, as I can relate it better to product de-

sign 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. Espe-

cially 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 exist-

ing 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

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

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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 proper-

ties 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 find-

ing the right materials in the right places. In fact

the workshop in Vertigo has very limited possibili-

ties 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 open-

source 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 nowa-

days a possibility for students to create a fine-

tuned 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 tech-

niques 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 mod-

eling 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 assign-

ment 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 exam-

ple 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.