Perfect Pencils

We will be making a perfect pencil sharpener.
Porter D Taylor B
Grade 7


Our question is how can we make a perfect pencil sharpener. 



I think that when we test the 30 Degree angle will be favoured over the other ones because that pencil angle is in the middle of all the other ones. 

I think that with the help of some 3-D printing, we’ll be able to make a sharpener that cuts at a perfect angle and a perfect length that our volunteers will determine. 


We watched these 9 videos to find out about how pencil sharpener's work and how they are made. As well as how to make one. 


We looked up the average dimensions of a pencil sharpener. We found that they are 2.5 × 1.7 × 1.1 cm. This is the Dimensions of the average pencil sharpener. We thought, how can we make this better? We changed the dimensions too, 2.5 x 1.5 x 1.5 cm.

To actually make our sharpener, Porter learned how to 3-D print so we can make the design. 






Controlled Variable


The pencils, paper and volunteers we test with, all these variables stayed the same. 


Manipulating Variable


We are changing the angle of the pencil lead that is sharpened.


Responding Variable


A perfectly sharpened pencil. 





  1. Buy all of the supplies that are needed. 
  2. First, we test to find out what the perfect angle and lead length for a pencil is. We do this by using a pocket knife and a protractor to carefully and precisely sharpen the pencils to different angles. 
  3.    Then we/the volunteers will test the durability while keeping it sharp to find that sweetspot. The volunteers will write 50 words on a sheet of paper for every pencil lead length. 
  4. Find out how pencil sharpeners are made and how they work. 
  5.  Create 3-D printing design 
  6. Print the sharpener and attach the razor blades. 




Plastic, paper, pencils, razor blades, pocket knives, and a 3-D printer. 


We noticed that the left handed writers prefered different pencils. Most of the students however prefered longer, skinnier pencil leads compared to shorter, wider ones. Everyone was getting tired mentally and physically after writing for a while. Even with the breaks in between. Over time, the volunteers were slowing down, and their writing was becoming less neat.                                          




For the data that we have collected, each pencil was marked out of 10 by 8 volunteers. We added up each score with a maximum score of 80


Most common comment:

Pencil 1.     10o :    57/80       “Tip breaks off too easily.”

Pencil 2.     20o :    57/80     “Very similar to the 1st one but better.”

Pencil 3.     30o :    59/80      “Very good.”

Pencil 4.     40o :    46/80     “Gets dull easily.”

Pencil 5.     50o :   34 /80 “Good at first, but dull afterwards.”  



We've concluded from this project that narrower pencils leads are prefered over wider ones, and that a pencil sharpened to a 30 degree angle is the best out of the pencils we tested. We 3-D printed a sharpener that sharpens to this angle and attached a razor blade to it.

This is our perfect pencil sharpener. 


Sadly, the sharpener that we made is not working. It is not working because the angle in which the blade sits is not steep enough for the blade to catch the pencil. We would also try to get a stronger plastic in our 3-D printer. It also would have been better if we changed where the screw hole is. 


The application for this product would be to be used by students, office workers, anyone who uses a pencil. We're hoping to make the lives of these people just a little better. 

Sources Of Error

If we were to do our project again we would have done the testing at the same time every day with every test supject. We tested Taylor's class in the middle of the day during lunch. Porter's tests were held at the end of the day, by doing this it made it so that Taylors classes hands were way less sore than Porters because they were at the end of the day instead of the middle. If we were to test again we would also make sure to print the writen test from the same printer. We had different thicknesses of paper, Taylor's papers were thinner and softer than Porter's. This might have resulted in different results if we used the same type of paper. 

If we were to do the pencil sharpener again we would make sure to:

- We would make the angle in which the blade sits sharper.

- We would also make an actual screw hole that fits the screw. 

- We would also make the inside if the sharpener smoother. 


We used the apps: Google, Google Classroom, Google Docs, Zoom, FaceTime, Thingiverse, Youtube, Amazon, Wikipedia, Blender, and Gmail. 


We used our school 3-D printer, and had help coordinating our project with our teachers Mr. Ryan, and Mrs. Saville.