Logitech M705 Teardown

newer version featured

Most copy from this post is quoted from the Logitech website linked here

The Logitech M705 “Marathon” is a wireless mouse, utilizing a USB “Unifying Receiver” in order to connect to your computer/devices. It includes a dual mode scroll wheel with graduated and free movement. The reason behind the Marathon name is based on this mouse’s 3 year battery life! It is a designed with ergonomics at the forefront, but is intended to work best with right handed users. It has 5 programable buttons, horizontal scrolling with a click of the wheel and precision optical tracking up to 1000dpi.

lets break it down!!!!

This mouse is part of Logitech’s 700 series wireless mice, the most expensive in there lineup and because of this, the build quality was quite good. Lets get into whats inside….


The main circuitry components that have serial numbers are as follows

  • Logitech E153302 optical mouse sensor
These sensors are made by simple processes of molding polycarbonate and polishing it for the lens. Then before attaching to the circuit board (in this case made from FR-4) an led and a camera are placed between the board and lens, which are then fused via heat. The pins seen on the left side of the board are intentionally not covered in plastic in order to be the output of images to the processor.
  • Side button circuit board 210-001841 Rev002
This is a circuit board with two actuators attached, designed to be used with the side buttons of my wireless mouse. This is all attached to a PCB and those cables would then attach back at the mother board.
  • Logitech 210-001818_003 Motherboard
This is the full view of the mother board or the brains of the mouse. This has a base of a PCB (standing for Printed Circuit Board) which are manufactured, whether by machine or by hand, by layering copper wire between a thin layer of polycarbonate, followed by more copper and more polycarbonate to complete the path of the circuit. It is then CNC’d into the final form. For what is applied on the surface, these are added next.
  • Optical encoder assembly

The two images above highlight how this mouse is able to interact with the scroll wheel. The scroll wheel assembly on the right sits at the front of the void in the motherboard, resting on each of those forms highlighted in the left image. In order to scroll, a light is produced through the clear lens, focused towards the unit on the right, which is able to detect it. Now, based on the slits that are seen in the scroll wheels inner circumference, when the light is unable to pass through the wheel, computer will know whether one is scrolling up or down. Both of these units are molded from some sort of PVC or ABS and adhered to the motherboard using heat or adhesive.

  • Construction of mouse body and other molded parts

Most all if not all of these pieces are made from ABS plastic and were injection molded. They would then go through a process of removing excess material, some more than others.

List of tools used in disassembly

  • #1 Phillips head screwdriver
  • X-Acto blade

My thoughts on the design

My thoughts on mouse design in general are that there are many many many bad mice designs that are still able to eeek by in every day use. However there are only a few that get it right, and you can feel it immediately. Logitech has always done this for me. In my opinion, the best part about the design here (and the design of all logitech mice) is the curve of the thumb area. I feel it is more effective than others because it allows one to feel like they are a part of the product and are integral to its functioning. Another thing that I very much enjoyed with this mouse is the design of the dual mode scroll wheel. It is so incredibly satisfying to the touch due to it being made out of metal, that it is a joy to press the button and freely fling the scroll wheel forward even when the computer is off.

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