Perfect Circle Maker: DIY

This started with the question "Sir, do you have a compass?"

I was taking a substitution class 6th and students were busy doing their classroom decoration work when a girl came to me and asked for a compass. Just to quiz her a little, I asked what she will do with compass? " I will make a circle" came the answer.

I decided to quiz her further. "How big do you want your circle to be?"

"4 cm in radius, Sir" she replied.

" What if you have to draw a circle of 30 cm? I asked.

She looked confused because she knows her compass will be too small to stretch that much.

I decided to give this as a Design Problem to students.

During their activity class, I asked them to closely observe a pair of compass and come up with a design that can work as a compass.

Students were divided into groups of 4 and 20 min was given to them to come up with a design. They can use their notebook to sketch their ideas.

After 20 min one member of each group comes forward and explains his teams' idea.

We did voting to select the best Design Idea and with our limited woodworking tools and experience, we started to give it a shape.

1) Wooden Piece

2) Saw

3) Nail

4) Pencil

5) Sandpaper

6) Hammer

7) C-clamp

8) Wood Planer

9) Measuring Tape

10) Bench drill and 7mm drill bit

Student decided to use waste material for this project. We visit schools' carpentry area and looked for some unused wooden piece. We found a 48x12 cm piece.

Using C-Clamp we secured it on a table and started cut 48x4 cm piece.

Using a sand paper sand the stick to give it a shine.

Then mark along the length of the stick. Each mark should be 1 cm apart.

Punch marks using hammer and nail. This will make it easy to drill and the hole will also be accurate.

We used 7 mm drill bit to drill through the punch.

Using wood planer or fold a sandpaper on a wooden block, smooth all the rough edges.

Drill a nail at one end of the stick so that the stick gets a pivot point.

A each hole is 1 cm apart, we can only draw circles having whole number radius. We just need to count the number of holes, adjust a pencil in the hole and holding the nail draw a circle.

Thank you.