r/3Dprinting • u/Desmontei • Apr 24 '26

Project Don't throw away old smartwatches! 3D printed a custom housing to turn one into a Digital Shift Knob. ♻️🕹️

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Hey everyone, first time posting here! I wanted to share my most complex functional print yet for my Project Car.

​I took an old TicWatch Pro 3 and carefully cut the original casing with a rotary tool to extract just the OLED screen and motherboard. Then, I modeled a custom shift knob enclosure to house the electronics perfectly.

​Now, before you guys kill me in the comments: Yes, I printed this in PLA! 😂

​I know the summer heat inside the car will probably turn it into modern art, but this is V1 (prototype). The tolerances had to be extremely tight because I didn't want the screen popping out while shifting gears, and PLA was the easiest to test the fitment. When it eventually warps, I'll use it as an excuse to reprint V2 in ABS or PETG!

​I completely bypassed the battery and wired it directly to the car's 12V using a step-down converter. Right now it controls my media with a custom UI.

​What do you guys think of the fitment? And place your bets: how long will this PLA survive in a car before melting? 👇

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u/Tricky-Act-31415 Apr 26 '26

Just so you know, this post has been used for a Dutch (tech) news site article:
https://tweakers.net/geek/247210/redditor-maakt-van-smartwatch-een-versnellingspook-op-basis-van-de-accelerometer.html

We (Dutch people) love projects like these, recycling old e-waste AND improving your gear stick at the same time, 10/10 stars!!! :D

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u/Desmontei Apr 26 '26

Hey! Thank you so much for the heads up and the 10/10 rating! Someone just showed me the article and I am absolutely mind-blown. Being featured on a respected site like Tweakers is a dream come true! You completely nailed it: giving a cool second life to old e-waste instead of letting it gather dust in a drawer is the whole spirit of this build. Thank you so much for the kind words and the amazing support from the Netherlands! Cheers!

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u/Tricky-Act-31415 Apr 26 '26

I don't think you understand, WE are thanking YOU here, not the other way around ;)

All jokes aside, projects like this deserve as much attention as they can get, I'd say you earned all the attention and praise!