Building a Recurve Bow

Marwa Afechkar

Building a recurve bow

Rubric Learning targets

Novice

3d.3 | Translating geometric properties to dierent dimensions and/ or planes.

Recognises specific s factors (enlargements dilations) and therefor recognises similar sha

5b.1 | Planning and conducting ethical scientific investigations OR conducting/applying the design cycle process to solve problems or innovate

Sudents completes a

design cycle as its laid out

Execute design cycle

process to build a rec bow

scale s and re apes.

d

curve

Specialist Applies knowledge of scale factors and similar shapes to real life problems.

Students evaluates their

use of the design cycle

and reflects upon its

performance.

My

To put a li

since 201

for archer

opportunit

design my

that I desi bow.

My driving

But before bow ?

What type

What are

What are

inspiration for the project

ittle more context to this project, I have been practicing Archery

16. I found in archery the calm and relaxation I need. My passion

ry never stopped after joining TGS, this term after finding out the

ty the Fab Lab offered, I couldn’t miss the chance to build and

y own bow. This is my process portfolio and a “How to” guide

igned to record the process of making the skeleton of a recurve

How can I build a recurve bow ?

g question is

e starting the project; What do I need to know about building a

e of wood should I use ?

the different steps of building a bow ?

the different things that I need to take in consideration ?

The recurve bow Recurve bows are popular for their versatility.

This bow got its name from its shape.

The center of the limbs curve towards the archer and the ends of the limbs curve away from the archer, which makes the bow more powerful. Its design does not require as much strength from the shooter. Recurve bows are great starting bows for those who want to get started with archery.

Learning how to make a recurve bows is one of the most important aspects of owning a well-structured bow. There is a wide variety of materials that are needed in the

The Mar Due to lack of equipment and time limit, Dan and I

characteristics that lean to the structure of a longb skeleton.

The Long bow Longbows are one of the oldest bows dating back to 1298.

It is a very simple bow made of a long curved piece of wood that is as tall as the archer. It does not have arrow rests or sights.

These bows are harder to aim and do not have the speed of a Compound or Recurve bow.

It takes a lot of practice to master this bow, and it is good for those who enjoy a challenge.

rwa Bow will be building a recurve bow but with simpler

bow. We will still be using lamination to have a strong

Type of wood For almost all types of bows the key components when it

comes to choosing the wood that we will be working with i the flexibility.

If the wood is not flexible enough, the bow will break.

Recurve bows can be made of several different woods, like osage orange, bamboo, red oak, hickory, ipe, eastern

The only wood that we could get our hands on was teak wood.

It has a high degree of natural durability, is moderately hard and

with low stiffness and shock resistance but an excellent decay r

and dimensional stability with a good acid resistance. Teak is a wood but it is not recommended to use teak for bows because very flexible.

is

e

.

d heavy

resistance

a hard it is not

Lamination

Now that we have our wood picked it

The lamination process is really important because it helps with the strength of the bow.

Laminated wood is wood that has been cut into thin layers, then glued together with the grain running parallel in each layer. Attributes that make the laminated wood stronger than it's solid counterpart include: Disruption of the grain due to the many layers of wood.

There are 5 steps in lamination. The first part of it is just laminating the dierent strips of wood to give us one strong strip that we can work with. The first lamination will just be with glue and small pressers that will hold it together until glued and the second lamination would be to give the bow its form and add the handle part to it.

t is time to start cutting wood strips to start the lamination process.

Lamination

To make the core lamination of our bow we cut it fro

this step twice because the first time we only worke performing the first lamination.

This time we used 3 strips of about 1m69. We put the g

cleaned off the edges for it to be ready for the second s

om the same block of wood of teak. We had to repeat

ed with 2 strips and that caused it to break after

glue in between each strip and after the glue has dried we

step of lamination

Translating geometric prop

To perform lamination we need to have a mold that will press u

wood from up and down so it can hold its shape and not move

molds are made in the oven, some are designed 3D on a com

then printed, but for me considering the time limit and lack of a

equipment, I cut out the shape that I wanted a piece of wood t previously laminated (so it’s strong) and I used it as a mold.

But for cutting out the shapes that I wanted from the piece of w

had to apply various geometrical properties and apply recogni difference scales that I was working with.

perties

up the

e. Some

mputer

available

that was

wood I

ize the

Translating geometric prop To cut my mold I followed the following sketch.

My plane was the wood piece/board. I drew 2 axes (x;y) and s points accordingly to form the wavy shape that I wanted.

The middle point represents the axe of symmetry. I had to cut and translate them in my plane.

In geometry, a translation is the shifting of a figure from one

without rotating, reflecting or changing its size. It is done by m

the figure the prescribed number of spaces on a coordinate pl the new figure.

My only tools were a ruler and a semi circle. I was using the ru

was conserving the same measurements and the semi circle t angles were conserved during the translation.

(Click on videos to see evidence of me translating and the applied work)

perties

started putting my

those shapes twice

e place to another

moving the vertices of

lane and then drawing

uler to make sure I

to make sure the

I tried to do my translation as accurate as I could but there were

Dan and I noticed when we put the 2 pieces together. So we fix

imperfections with sand paper and there we had it. Our mold w

We too

that we

lamina

top of t

the mo

the mid

was pl

middle

Then we pressed the strip of wood tightly together and left it to laminate

e still some flaws that

xed the little

was ready!

ok the wood piece

e previously

ated and placed on

the bottom part of

old in such a way that

ddle of wood strip

laced on top of the

e of the mold

Why the first try failed and t

The first try of

main reasons

and they were

There was no

we decided to

them together

The other rea

amount of tim

total of 2 hour

What we learn succeed.

During our se

the results we

the second one succeeded.

f lamination just like previously mentioned failed, due to 2

s. We only had 2 strips of wood that we laminated together

e both very think so when the mold put pressure on them.

o strength or resistance so they just broke. That is when

o use 3 different wood strips that are thinner then laminate

r.

ason that caused the failure was that we left for such little

me in lamination between the molds. We only left it for a

rs but it should have stayed in the mold overnight.

nt from this failure was what cause the second one to

econd try we left it overnight to laminate, it didn’t break and

ere pleasing.

Now it is time to start shaping our bow, round th

I drew two center lines on the bow. one crosswise and the o

All measurements should be very carefully made as even a be reflected in the accuracy of the finished bow, so I made

circle to preserve the right angles of each point that translat

I measure the exact distance from, center to end of either fa

marked off equal distance other limb. Then I marked off bow

required width, then layer out limb tapers from end of fadeo

Then I cut away the excess limb so it is the hight that I wan

Having determined which is to be the up- per limb and whic

started rounding and thinning the edges using sand paper a

available tool then. The lines that I marked before helped m

myself throughout the sanding to not go over the line and h symmetrical, perfect shape

he edges and make the limbs thinner.

other lengthwise.

a slight error will sure to use semi

ted on the line.

adeout and

w tips for

out to bow tip.

nt.

ch the lower, I

as it was the only

me to guide

have a

When using the sanding machine it was really impor

focused and not press too hard on the bow. One tim made a bumpy on the bow that is was quite hard to

This sanding technique helped to bring everything to

give the bow its shape including the grip and the fina limbs.

(Click on video to see evidence of practicing sanding

rtant to stay

me I did and it get rid off.

ogether and

al form of the

g my bow)

THE BOW !

I oiled the bow to look shiny and smoother and let it dry.

Due to time limit I couldn’t carry on with the final details of the bow like carving the grip and attaching the string. But this is still the skeleton of what each bow consists of and making was a success.

Thanks to Dan for mentoring this project !!!!!