Logitech MX Master 3 leftie (Update #3 FIRST WORKING PROTOTYPE)

So I'm in the process of designing a left handed version of the Logitech MX Master 3 since I've long given up hopes for Logitech to ever cater to the left handed marked. (for now I still think it's doable with only a donor MX Master 3 and printed parts without modifications to the pcb's)

This model is only my first step but I thought of sharing it anyway because the first time I held this model in my left hand it just felt so right. 

Creating this model in the Fusion 360 form workspace was a huge step for me to take because I'm only experienced in parametric modelling and the thought of not being able to fully determine a design with dimensions has honestly always scared me. 

Well it still does, because it was hell, but kinda fun because at least I got a result. But ask me now to redo it from scratch and I will fail, I've tried. 

Now comes the fun part where I try and fit all of the components inside, design the inner mounting points and probably use a few kg's of filament to try and retry to get that perfect(ish) fit. For now I've kept the overall size to 105% of the original but with the same arch height. I've always felt the original to be just a smidgen too short and liked the idea of having some more empty space to work with inside

I've included here a solid model and a shell with rudimentary holes for components (top + bottom)
There is still A LOT of work to do to get anywhere near a final model for a conversion but this outer shape is just too fun to play with in the hand. 

Update 01/03/'25 (ddmmyy): 

I've come a long way in designing the inside of the mouse by now. The bottom plate is quite finished but the top still requires a lot of work

Update #2 (03/03/2025)

The side-scroll wheel has been installed ! I had to file away a little piece of the plastic mount of the assembly to make it fit. Scroll direction will be reversed but maybe it can be changed in the software…

I had to really push it as much to the side as possible to avoid the motherboard and battery but still I had to  file away a  corner of the plastic mount. 

The left and right click buttons also work but not as smooth as I would like. I will be testing some ptfe tape on the surface of the part that pushed the button

Now onto the topside button 

It's not at all finished yet but I could not resist sharing this working prototype (only thumb button is not installed yet)

• Screw holes need to be optimised (half a mm really makes a difference)
• Click sensitivity is not yet optimal. I have to adjust some minor distances and clean the surfaces of the print
• Closing mechanism needs some extra guiding and extra mounting points
• The flat thumb button needs to be installed and I still need to figure out a click solution (I'm thinking of doing a TPU patch onto the shell)
• I need to figure out the ideal filament for this print. PLA is too stiff, Nylon is too overhang sensitive, all CF filaments are too stiff. I'm thinking of PLA-HR from Biqu which I have some leftover from printing a besketball

Please allow me some time to fine tune the model before I share it.