1. ~Cutting, Marking, Measuring, and Sanding dowels~ Monday
18/04/11
Today I did measure, mark, cut, and sand the dowels. I
needed 8 dowels more. So first, I got long stick wood,
and measured 7.7cm each. I changed my plane. Before
the dowels has to be 8cm, but I got small then 8cm
dowels, so I changed to 7.7cm. After cut the dowels, I
checked if the dowels are all same size. It was not same
size still. So I have to
sand it. I used flat file to
sand dowels, but I
thought it would take long
time to sand whole
dowels. So I asked Mr.
Anderson to use disk
sander for sand the dowels faster. He said ‘yes’. So I
started to measure whole dowels to 7.5cm, and use
pencil to marked. After marked whole dowels, I got
goggle and hair band to use disk sander. Also after I got
20 dowels. I calculated how many dowels do I use. First,
the bases are circle, so I calculated circumference of the
base.
How to find
circumference?
2πx x=radius of circle
My base of radius= 7.5cm
Formula: 2π7.5= approximate 47cm
So the circumference is 47cm. It not finish yet, then I calculated how many

2. dowels can be put in the around the circle base.
The Formula is: circumference ÷ (2cm+1cm)
2cm is an opening between the dowel and the dowel. 1cm is dowel of width.
The answer is approximate 16 dowels. So my plane is the opening between
dowel and dowel will be 2cm.
NEXT
I didn’t have time to check the dowels length size. So next class I have to check
the dowels size, and if the sizes are all same, I want to mark in base to make
hole for put these dowels. But if the sizes are not same, I will repeat measure,
mark and sand dowels.
Emotion
I thought math formula is REALLY useful!! Because today, I wanted to find how
many cm do I have to open and mark for drill positions, and I used math formula
to find that.
AOI-Human Ingenuity
Today I used math formula to find circumference of base. Today I thought math
is really important for DT. I did good invention to do this project.