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Publications :: Various Papers :: Mouse Modding - How to "fix" your Logitech wheel mouse

2003/03/12, version 1.1, Daniel Mettler

[1]

Content

Introduction - Hey, what's up man?!
The Mission. Impossible?
Take-off: How to make the mouse scroll smoothly and silently
Behind the scenes: Labelled pics
Video snippets: Before and after
So what? - Outlook
Annotations

1. Introduction - Hey, what's up man?!

Although the Logitech USB wheel mouse I use with my notebook computer is a nice device in general, there are two things I have never been particularly happy with:

When scrolling using the mouse wheel, the scrolling is not really smooth and continuous but rather happens in discrete little steps.
A "click" sound is audible upon every little step when scrolling with the wheel. This noisy sound can be pretty annoying when scrolling fast - and embarrassing when working in "supposed-to-be-silent" public places like libraries.

2. The Mission. Impossible?

So I finally decided to fix this "broken-by-design" piece of hardware to make it a) scroll smoothly and b) scroll silently. Surprisingly this was easier than first imagined as I did not even have to cut, saw or glue anything. All needed is a small screwdriver (for cross screws -> I used a small swiss pocket-knife) and a couple of minutes time.

3. Take-off: How to make the mouse scroll smoothly and silently

Now here's how to "mod" [2] your Logitech wheel mouse:

First of all, open your mouse [3] by unscrewing the tiny cross screw at the bottom of your mouse:
Lift off the green circuit board.
Detach the wheel and its frame from the green circuit board. This can be done by pressing the small latches of the frame at the bottom of the circuit board.
Open the wheel's frame: Press the latches on the right hand side of the frame.
Separate the mouse wheel from the rest of the frame.
On top of the frame, on the left hand side, there is a tiny plastic wheel. Just remove it. That's the culprit responsible for the noise!
Now reassemble your mouse: Put the mouse wheel back in the frame, reassemble the frame, attach the frame to the circuit board, place the circuit board in the bottom half of the mouse case, mount the top case and fix it all with the screw.

NB: If unsure, you may want to take a look at the whole series of pictures

4. Behind the scenes: Labelled pics

This is the tiny plastic wheel (yellow arrow points to the axis) which makes the rattling noise when scrolling..

..in conjunction with this "cog-wheel" (yellow arrow)

Overview of the circuit board: Switches for the 2 mouse buttons and the "wheel button" (3rd mouse button) shown in green, optical sensors for measuring the rotations of the mouse wheel and the rolling of the mouse ball (translated to rotations of 2 orthogonal wheels) shown in yellow.

5. Video snippets: Before and after

Compare the noise on these two 4 sec videos (AVI format):

before the modifications: before.avi (3.6 MB)
after the modifications: after.avi (3.2 MB)

And of course: Smooth, continuous scrolling!

I'd say: Mission successful! :)

6. So what? - Outlook

Actually I would like to "mod" my MS Intellimouse Explorer too (similar problem there). Unfortunately it looks like its case can't be opened without destroying it.
Obviously computer mice are very simple devices which are well supported by all major operating systems. This makes them great toys for quickly developing control or measurement prototypes. See Ka-Ping Yee's cool peephole display prototype for example. BTW. Ka-Ping Yee has some pretty cool projects and ideas! Take a look at his home page! :)

7. Annotations

[1] As I have not bought a decent digital photo cam (such as the Casio Exilim EX-S3 -> see also here and here, the Casio Exilim EX-M2, the Sony DSC-U20 or the Nikon Coolpix SQ) yet, my webcam had to suffice for taking pictures :|
[2] Note that in general the guarantee expires when modifying hardware. Yep, that's the way it is.
[3] Beware! Do not try this with a real mouse! LOL.

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