Introduction: CNC Keyboard Travel Cover
Welcome everyone, this keyboard travel cover is a simple project for anyone with access to a CNC router. As a mechanical engineering and computer science college student, I find myself bringing my keyboard everywhere to classes and labs. I often see other students stuffing their expensive keyboards into their bags or using soft covers that don't really protect the keys. Machined out of maple hardwood on a CNC router, this simple yet robust design uses elastic bands to secure onto the top of a keyboard. Extra elastic bands can be used as a wire organizer. We will go over how to design a unique keyboard cover to fit onto your own keyboard and how to make tool paths for this part in Fusion 360. Let's get started!
- Board of hardwood or plywood larger than keyboard footprint and 2cm (0.75”) or thicker
- 120cm (4ft) of 2.5cm (1") wide elastic band
- Sewing thread or hot glue
- CNC Router
- Ruler or measuring device
- Sand paper
- Sewing needle if using thread
- Optional wood stain, finish, or clear coat
Step 1: Measuring Your Keyboard Dimensions
Chances are that your keyboard will have different outer dimensions than mine, therefore you will have to design this part yourself using your own measurements. There are 4 keyboard dimensions that you need to measure:
- Width of keyboard chassis
- Length of keyboard chassis
- Distance between chassis top and key cap top
- Distance between chassis edge and key cap edge
Take a look at the images to make sure you are taking the right dimensions. Don't forget to round up the length and width about 0.5mm (0.02") so that there is a nice sliding fit between the keyboard and cover. These measurements will help with the next step when you create the cad model.
Step 2: Creating the CAD Model
After noting down all of your custom dimensions, its time to model the part. I will assume you have a basic understanding of how to model parts in a CAD program. If not, there are plenty of resources and tutorials online.
- The length and width will correspond to the dimensions of the first ledge represented by the blue rectangle.
- Don't forget to add the 0.5mm (0.02") to these dimensions for a smooth sliding fit.
- The distance between the top of the chassis and top of the key cap corresponds to the distance between the two red faces.
- The distance between the edge of chassis and edge of the key cap defines the maximum distance between the green faces on all sides.
Don't forget to add slots to hide the elastic band ends. The slot dimensions should be slightly larger than the width of your elastic band (on the long axis) and the diameter of the end mill you plan on using (on the short axis).Yellow slots on the last image will keep the bands securing the keyboard in place and the light blue slots are for optional for extra cable management.
Step 3: CAM Toolpaths in Fusion 360
Arguably the most difficult part of this project is creating tool paths that will cleanly machine this keyboard cover. But do not worry, we will go through each tool path together to make sure your keyboard cover machines nicely. I can guarantee that this order of tool paths will result in a clean operation.
- If you created the keyboard cover model in another CAD program like I have, you need to export the model in .step format then import it into Fusion.
- You can skip exporting and importing if you already used Fusion for the CAD design.
- After importing the part into Fusion, switch from design to manufacturing from the drop down on the top left.
- Manufacturing mode will switch all of the functions in the toolbar from CAD to CAM functions.
- Choose machine setup work coordinate system and stock dimensions.
- Your work coordinate system may be different depending on the CNC router you have access to.
- Set the stock dimensions to the dimensions of the raw material you plan on using.
- The first tool path I choose is a pocket clear to quickly remove material.
- Make sure to leave radial and axial stock to leave for future finishing passes.
- To finish the floor of the pocket, make a parallel tool path.
- I decided to split up the parallel tool path into two parts too keep the machining marks parallel to the part geometry.
- Switching end mills at this point is optional, but I switched from a 1/4" 3 flute end mill for roughing and floor finishing to a 1/8" 2 flute end mill for wall finishing and contouring.
- The smaller diameter end mill is able to make tighter radius inside corners and slots.
- Using either the same end mill or another smaller end mill, run some 2d contours to cut out the slots and finish all the inside walls.
- Hang in there, only one more tool path to generate. A 2d contour on the outer walls will finish this part up.
- Unless your using double sided tape to hold down the wood piece, I would recommend adding tabs to ensure the cover doesn't go airborne at the end.
- After all of the tool paths are generated and you are satisfied with the simulation, post process everything and send it to the CNC controller as g-code.
Spending an adequate amount of time in CAM and fine tuning cutting parameters decreases the chances of the CNC router doing something unexpected. Every machinist knows to take their time with preparation.
Step 4: Setup and Run the CNC Router
In my opinion, this is the most exciting part of the project. However, this step is also the most likely place where things can go wrong. Setting up the CNC router for cutting is pretty straightforward whether you use screws, clamps or double sided tape to hold down the wood.
- No matter which world holding method you choose make sure that the wood is securely attached to the spoil-board.
- After work holding open your g-code file in your CNC controller and watch the machine do some amazing work.
Some light sanding will clean up all the fibers from the edges that the CNC router was unable to cut off.
Step 5: Finishing the Wood and Adding Elastic Bands
You may like the bare wood finish after some light sanding or you would like to step it up a notch with some wood stain or polyurethane to bring out the natural wood color. Adding some sort of protection or clear coat is a good idea to preserve the hardwood from handling.
- If you are putting any sort of finish or coating, you should do it before adding the elastic bands.
- You may choose to use thread or hot glue to close the elastic band loop. I found that sewing the elastic band created a more permanent connection.
After a test fit, give yourself a pat on the back and admire your work!
Whether it be a different slot design or a different combination of hardwoods and plywoods, I'd love to see how some of you will modify this simple design in your own way. This project is great for any mechanical keyboard enthusiasts you know or even as a gift for your office friends. If you've made it this far, I want to thank you for reading my very first Instructable.