Redesigned Mouse W/ LED Lighting

I was inspired by romanursuhack RomanUrsuHack's project where he used an existing older mouse model and inserted an LED to channel light through fiber optic cables to create a "light-up star effect". I decided to take up a similar project as my own for Ms. Berbawy's Principles of Engineering class at Irvington High School. I reverse engineered and redesigned an older mouse model, created a new top shell in CAD, and inserted LEDs similar to the one RomanUrsuHack had in his video.

- An old mouse

- solder

- soldering iron

- fiber-optic cables

- LED

- 220 ohm resistor

- jumper wires

- wire cutters

- heat shrink tubing

- 3D printer (Ender 3 Pro)

- Filament (PETG)

- CAD Software (Onshape)

- ruler/measuring tape

- dial caliper

- sand paper

- foam

- hot glue

I personally used an IBM MO38UO as my mouse of choice. All of my CAD models and techniques will be based and customized for this specific mouse, but the general steps and guidance is applicable to nearly all mice. I recommend an inexpensive mouse that isn't very valuable. Be sure to check that the mouse is functioning. However, make sure the mouse is not too old as I encountered difficulty while using a BTC M871 mouse, which had a mini DIN port instead of a USB port. Ultimately, my attempt with BTC M871 mouse, while successful, was hindered due to 3 challenges:

1. Loss of data due to the adapter that I was using.

2. Unknown hardware issues due to time degradation.

3. The mouse driver only works with Windows XP or systems before it.

First, you need to use a measuring instrument (I used a set of dial calipers for more precision) to measure the total length and width of the top shell's outline along with any common shapes such as ellipses and circles. I recommend taking repeated measurements to ensure accuracy.

When creating the CAD drawing (I used OnShape as my software) for the new mouse design, I ppicked some points at the shell where the curvature and height have significant changes to create construction lines. Doing so, will allow you to easier change the shape of the mouse in terms of the height at different points.

After determining my points and shapes, I created a general outline and fill out the dimensions in the new sketch, similar to the picture above.

*All dimensions are in centimeters.

Next, I created a side-view sketch for my design, this will be used to represent the existing bottom shell. I inserted the measured dimension of the height and length at each point.

I made sure to give the height of the existing material of the bottom shell, and not the desired height of top shell.

After filling out the crucial points, I connected the points at the top with 3-point curves to fill out the sketch. I left the radius of the curves undefined for the moment in case I needed to edit the curves to adjust for the height of the shell itself.

I then extruded the top view sketch from Step 2 with the standard depth of 2.5 cm to create the block of material. In the next steps, I remove CAD features to create the needed shape.

To create the basic shape, I used the side sketch to remove material through the entire block.

I made sure to have the second end position selected and have the "through all" option selected for the position to truly have the removal through the entire block.

Then I created a new sketch from the top view from the y-axis. I measured the width and length of the gap for the scroll wheel starting from the tip of the mouse. I found that a length of 3cm and a width of 1.1 cm is sufficient.

Next, I copied and pasted the original side sketch onto a new sketch, then offset the flat tail end by 0.087 cm, offset the middle curve that consists of 3 crucial points by 0.3 cm, and finally offset the tip of the curve by 0.15 cm.

Then I connected the offset tail to the middle portion and later the middle curve to the tip of the curve by another 3-point curve to round off the sharp edge similar to the picture above.

Lastly, I created another 3-point curve that connects the shell's tail end to the very top of the shell itself to allow room for the led and fiber optic cables. (I used a radius of 11.1 cm)

To define the shape, I copied and pasted the previous sketch onto a new sketch. I made sure the part is visible so I can see where to remove material, then create an outline of the parts outside of the sketch of the shape for the top shell.

Here I made sure to convert the lines and curves that formulate the actual shape of the shell into construction lines, while keeping the lines that border the outline removal as object lines.

Next I created one new extrusion using the previous sketch to remove material and create the shape of the shell.

I made sure to use 2 end positions with the option "though all" to move material through the entirety of the block.

I then created another new extrusion using the scroll wheel sketch (Step 7) to remove material to create the gap for the scroll wheel. I used the "through all" option and make sure the removal is facing the correct way (towards the physical part).

I created the clicker extensions so the mouse shell would hit the sensor. I created 6x6 mm squares and positioned them where the sensors are located in the actual mouse.

I used construction lines as references and to set the position of the sensors as shown in the picture.

I created a new extrusion and selected "new" to create new parts using the previous sketch. I later adjusted the height of the actual extension in the 3D printer's slicing software according to the physical shell's compatibility with the bottom shell.

I selected the bottom faces of the top shell and used the shell function with a 0.29 cm shell thickness to hollow out the insides of the mouse. Then created another shell function with the 2 extensions selected but this time made sure that the hollow option is check marked, and input a 0.1 cm shell thickness.

I used an Ender 3 Pro as my 3D printer and PETG as my filament material.

I made sure the print bed was leveled, and pre-heated according to the specified filament temperature.

These are my 3D printer settings for the shell.

*** Make sure that the longest length, width, and height is accurate according to the CAD file. Also, be sure to print upside-down from the top of the shell in the shape of a "u". This will make it easier to get rid of supports later on.

These are my 3D print settings for the extension.

Make sure that the longest length and width is accurate according to the CAD file. For the height, after 3D printing the top shell, use the shell and a measuring tool (dial caliber) to find a suitable height for the extension to input in the slicing software.

1. I had first disconnect Pins/Wires from circuit board.

2. Use a wire stripper to cut the outer wire and reveal the right most black and red inner wires.

3. Cut and strip both wires.

4. Solder the 220 ohm resistor on the anode/longer side of the LED. Then solder an equal length wire on the cathode/shorter side for equal length and balance.

5. Use a heat shrink tubing to cover the exposed metal on both sides of the LED.

6. Put more heat shrink tubing along the red and black wires to cover the exposed parts after step 7.

7. Solder the resistor to the red wire and the LED's wire to the black wire. Making sure the cut black and red wires are jointly soldered, creating a parallel circuit.

8. Heat the tubes with the iron to shrink them.

Next use hot glue to attach the extensions on the bottom of the shell that correlates with the clicking sensors.

Then cut out foam to fill out the gaps on the side of the mouse and to act as a easily penetrable material for the optic fiber cables.

Cut out some fiber optic cables, cut more than length than expected and if needed you can later cut out the excess.

Finally, put the cables through the foam and hot glue the cables to the inside part of the foam as from above. Then bind the cables together using tape or hot glue into a bundle.

Finally, cut a small piece of non-transparent straw and tape it onto the led. Next, insert the fiber optic cables into the straw and then seal up the top shell with the bottom shell via hot glue at the very back of the mouse, so it doesn't affect the clicking of the mouse.

Here are the STL files for the top shell and 2 extensions, feel free to use them however you like. I hope you enjoyed this small guide to creating a redesigned mouse shell. I really enjoyed making this project and hope you will have the same amount of fun that I had throughout the project.