Logitech G703 Scroll Wheel Axle Replacement

Overview

A while back, the scroll wheel of my G703 failed - it spun freely but no scrolling would register. Opening up the mouse to take a look revealed that the left-side axle of the wheel, which sits inside of and spins the rotary encoder, had broken off. I designed this model as a quick and dirty fix until I could source a proper replacement for the wheel. It certainly isn't intended to hold up to long-term use, but should be enough to let your mouse limp along for a little bit if you're in the same situation (I got five weeks of use out of it before I was able to replace the wheel and didn't notice any qualitative differences to the stock wheel when I was using it).

It might very well work on other Logitech G-Series mice, but I don't have access to any to test and don't want to make any promises.

BoM/Hardware

No non-printed hardware required (besides what's in your mouse, obviously). One #0 Phillips head screwdriver required to access your mouse's scroll wheel.

(Dis)Assembly Instructions

• Remove the part from the print bed and remove the brim.

• To access your mouse's scroll wheel:

  • Peel off the two low-friction pads from the bottom of the mouse.

  • Remove the four screws and set them to the side.

  • Gently separate the top and bottom halves of the mouse, taking care not to damage the ribbon cable connecting the two (trust me - not a fun mistake to make).

  • Remove the two breakout boards on either side of the scroll wheel; they're attached by two screws each. Set the screws aside.

• Remove the scroll wheel's axle from the encoder (a mechanical pencil can help push it out if a piece has broken off inside).

• Press the printed part into the encoder side of the scroll wheel and ensure it fits tightly.

• Seat the axle inside the encoder and make sure it also fits tightly.

• Replace the scroll wheel and both boards, screwing them back into place. Do one final check to make sure the wheel spins freely and adjust if necessary.

• Reattach the top and bottom halves of the mouse and refasten with the four screws.

• Replace the low-friction pads on the bottom of the mouse if the adhesive isn't too damaged (otherwise just toss them).

• Done!

Print Settings

A 0.25 mm nozzle or smaller is required if you want to produce this part on an FDM printer; anything larger doesn't have enough resolution. A brim is strongly recommended due to the very small amount of bed contact. Depending on your printer's tuning, I would also recommend printing a few versions of this part scaled from 98% to 102%, as the precision required for a press-fit into the scroll wheel is fairly tight.

If you have access to a resin printer, this would probably print fantastically on one (although I can't recommend any print settings in that case) and would likely also have superior material properties.