DIY a Tablet Stand to Meet My Favorite View Angle


It’s easy to make a tablet stand with corrugated fiberboard (aka corrugated paper). To customize view angle, I use Google Calculator and trigonometric functions to do the math.

Design Draft

First, I disassemble a corrugated paper box and draw a design draft:

A design draft of a tablet stand with a stopper
A design draft of a tablet stand with a stopper

Trigonometric Functions

Here is what I have already known:

  1. Max length (A+B+C+D) of corrugated paper.
  2. A is equal to tablet height.

At first, I just let b (length of B) = c (length of C) = d (length of D) = (total length – tablet height) / 3. Then I get a stand with 60° view angle according to an equilateral triangle.

How to customize θ? I decide to let b = c to make it a Isosceles triangle.

An isosceles triangle
An isosceles triangle.

Based on Pythagorean theorem, I get d = 2b * cosθ or use the formula below:

Pythagorean theorem of the lengths among an isosceles triangle
Pythagorean theorem of the lengths among an isosceles triangle.

You need a scientific calculator which supports trigonometric functions here. Because my Sony Xperia C3‘s build-in calculator doesn’t support Inverse trigonometric functions, I decide to install Google Calculator after reading 10 best calculator apps for Android on Android Authority.

Google Calculator

Google Calculator with cosine
Google Calculator with cosine.

Launch and swipe left, you see more functions and operators. There is a DEG (degree) or RAD (radian) on the upper left. Click to select the unit you need.

If you want to calculate θ with a given d, you need to use inverse trigonometric functions. In some calculators, there is a Inv (inverse) button to help you switch from sine to arcsine (or sin¯¹(x)) and vice versa. But in Google Calculator, you need to tap and hold for about 0.5 second. It enters the inverse trigonometric function automatically as below:

Google Calculator with arcsine
Google Calculator with arcsine.

My Tablet Stand

Here is a photo of my tablet stand. It helps me to recall trigonometric functions and Pythagorean theorem learned in junior high school. They are very helpful in engineering!

My DIY tablet stand with corrugated fiberboard
My DIY tablet stand with corrugated fiberboard

Reference

  1. Android Authority: 10 best calculator apps for Android
  2. Google play: Calculator
  3. Sony: Xperia C3 Specifications
  4. Wiki: Corrugated fiberboard
  5. Wiki: Degree (angle)
  6. Wiki: Equilateral triangle
  7. Wiki: Inverse trigonometric functions
  8. Wiki: Isosceles triangle
  9. Wiki: Pythagorean theorem
  10. Wiki: Radian
  11. Wiki: Scientific calculator
  12. Wiki: Trigonometric functions
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