Intro: Calculator Holder Using Cardboard
This small project is to craft a calculator holder out of waste cardboard sheet with minimal glueing or taping, with a construction time of within a couple of hours.
Background and use-case
Many of you must have faced a work situation when you have to use a mix of PC/laptop, a paper drawing or report and a calculator for side computations.
In such situations, you often wish that the face of the calculator was at an angle, so that you could place it at the periphery of your work area, and still use it from there without having to move it back and forth. Keeping it flat would limit the visibility of the LCD beyond a distance.
What if you could craft such a calculator holder out of waste cardboard sheet with minimal glueing or taping within a couple of hours ?
Interested ? Read on for a good Sunday afternoon project to craft a simple object of great utility for your workbench ...
Step 1: You Will Need
- A contiguous piece of corrugated cardboard of 1mm or more thickness. You can recycle this from a carton of candies, fruits or electronics.
- A3 sized plain paper sheet
- Glue suitable for cardboard/plywood
- Stationary Items : Ruler (preferably steel), box-cutter, tape, pins, pencil, rubber-bands etc.
Step 2: Overview of Construction
- On an A3 sized paper sheet , create outline drawing of the flattened shape the object. (See File : calculator-holder-main.pdf)
- Cut (1) along the outline. This becomes the template to be reproduced on the cardboard. (see image-3.jpg)
- If you wish to review how your finished object will look like, you can opt to 'assemble' (2) into shape. If you wish to make changes, you can always go back and redo (1).
- Secure (1) over the cardboard using pins or double sided tape so that it does not shift in (5)
- Mark out the edges & corners from the outline onto the cardboard sheet using a fine tipped pin or needle. These include the edges that will be cut, and the edges that will be bent (see file :calculator-holder-cut-bend.pdf)
- In (5), separate the cardboard from the template (2).
- Using a fine tipped pencil and ruler, draw the line-edges on cardboard as they occur on the template (2).
- Cut the cardboard along the outline to complete the reproduction of template on the cardboard. Use box-cutter guided by ruler to get a smooth cut. Note the special cut for the "ears" stops that keep the calculator in position (see image-2.jpg).
- Select one side of (8) to create grooves along its bending edges (see file :calculator-holder-cut-bend.pdf) to aid sharply bent edges. The depth of these grooves is half the thickness of the cardboard sheet.
- Carefully cut a groove along each of the bent edges of (8) using a box-cutter or a blade of a common pencil sharpener. Note the special handling for the "ears" stops (see(8), image-2.jpg).
- Carefully bend along the bending edges by using ruler as a guide on opposite side of cardboard. Carefully handle the "ears" stops while bending, as they are intended to "open out" on bending.
- "Assemble" the object and identify the sides/faces that need to be glued. These should be 7 in number. Note how the "bottom" stop is bent and glued into place .
- Glue (12) into place and secure the joints by tape or rubber bands till the glue dries up.
- Your calculator holder is ready ! The object may require some leveling adjustment which is easily accomplished by glueing cardboard pieces appropriately on bottom face. You can also glue paper strips to cover the grooves cut in step(j).
Step 3: Improvisations
The outline of the object can be easily created manually on paper, using elementary drafting techniques.
However, a more rigorous approach can be taken by using 2D CAD programs on your desktop/laptop. Freeware/Open-Source applications like QCAD or LibreCAD are well suited for this purpose.
You can create the design on CAD, print out the outline for step (a), and save the design in a standardized format (e,g DXF) for later reuse, modification or exchange.
The dxf used by me for my design is included as example. I have used QCAD as the design tool.
Step 4: Closing Notes
You can adapt the methodology outlined in this project , make your improvisations to create holders for your mobile-phone, tablet, Multi-meter, desk-phone etc.
Have fun experimenting with this instructable !!!