3D Print A Thinner Car Key

Almost all modern cars come with keyless entry, some even come with keyless start. Of course, the price you pay for this technology is a bulky plastic keyfob that is an absolute pain to remove from your pockets, and generally spoils the lines of your carefully chosen outfit. [Jeremy] decided enough was enough.

The project begins with a careful disassembly of the original key. This is important to avoid damaging the PCB inside, particularly if there are any delicate wire links between different sections of the keyfob. With the piece disassembled, it was then time to start designing a replacement encasement to hasten escapement while pacing the pavement.

The 3D printer really is the perfect tool for the job here, and [Jeremy] employs it well. With this being a proximity-based keyfob, the buttons are only necessary if you want to operate the locks at a distance. They simply took up too much vertical space, so they had to go. In the end, with a redesigned housing for the PCB, and while retaining the backup mechanical key, the new fob is just 11mm, down from 18mm – a nearly 40% saving in thickness!

It’s a tidy way to clean up your pockets and make life easier. We’ve seen similar work before, too.

30 thoughts on “3D Print A Thinner Car Key

  1. Man…I’m with Jeremy… When I drive my buddy’s 2015 Impala, after the has… Imbibed… My first thought is invariably “And he used to make fun of ME for carrying a bulky TI-85 everywhere”

  2. To each his own but what exactly does this accomplish?
    I own the exact FOB myself and this introduction is massively exacggerated.
    “Of course, the price you pay for this technology is a bulky plastic keyfob that is an absolute pain to remove from your pockets, and generally spoils the lines of your carefully chosen outfit.”

    Well surely this is the case – this Fob fits _perfectly_ into the small Pocketwatch-pocket in every jeans that I have ever worn. It’s so unobstrusive that I sometimes forgot I had it with me.
    Of couse I have the FOB alone and not 5 million keys with it on my keychain. So yeah … this fob is absolutely bulky and overkill … not.
    I have no clue what a new fob for a BMW with keyless entry costs, but it won’t be cheap if you ever break yours OR you come into the pain to sell that beautiful BMW with M-Spports package (or even M performance) … so yeah, good job with that ;-)

    Sorry to sound absolutely cynical but this is one of these things that I can’t understand. The FOB is not intrusive, bulky or “unnecessary big”. If you look at the pictures, it’s designed to withstand an impact and of course – have buttons. Sure he said he doesn’t need them but I think the ability to unlock your hatch while someone needs to take something and and you not being right next to your car is reason enough to stick with the original.

    It’s nicely done, but this for me is a case of: Neat and good execution, but not necessary.

    1. Aren’t most hacks “not necessary”, as you can do them another way? … This works for him. That’s good enough for me. In fact I ought to have done this for my Laguna keyfob thing but alas – no 3d printer back then.

      I have to agree with your other comments though.

      1. Yeah I know what you mean.
        I get that. Often these hacks are to make someones life more simple or convenient, which is totally fine.
        But in my opinion, the FOB of a pretty expensive BMW with M-package or M-Performance is not cheap by any means. So I would never crack open that remote. If you do that because the HUGE blob of plastic from a cheapo Hyundai or something like that is bothersome, yeah I get that (See linked article that inspired him to do that). But it’s a recent car with a pretty modern and not so bulky remote. Don’t know. Just doesn’t feel right. But again – to each his own, don’t get me wrong here.

        I have driven cars with way thicker remotes or even crappy buttons that were made from rubber so it breaks down after a few years of use and looks like your dog chewed on it. Then it’s a nobrainer to do that kind of stuff.

        But again – neat process, but the color seems off :-P

    2. Agreed Black…quite pointless.
      I also agree with ‘to each his own’ but this story isn’t impressive & has no business being a hack because it cannot exactly accomplish the same thing as that which it replaces due to the loss of button functionality.

      Moreover, as hacks go, there has to be a clear positive net gain/loss of something…time, expense, steps, etc. Space savings is the only thing here but the rest is a clear drawback for the points you’ve already made.

      1. Out of curisosity:
        You don’t seem to use the lower windows function at all, do you?
        I use it often. Even if I have keyless access. When it’s hot, I take out my fob, hold the unlock button and release the initial cloud of hot air from my car. So you lose that aswell. To close the doors, I hold the handle until the windows are up (do always the same with the mirrors aswell). So that’s fine. But opening windows while walking to the car is needed for me.

    3. I have a couple of keys on the fob and not all my pants have that little pocket, unfortunately.

      Primarily, I’ve always thought the key could be smaller and it was a challenge to see how small I could make it while still being strong.

    1. the problem with the Renault cards is they can easily be bent if, say sat on in a back pocket, then they invariably stop working. and because they are active devices you have a non start condition. they are also a pita to cut open and reshell. have to say in not a fan but plenty folks like the form factor

      1. I’ve had to reshell my old Laguna’s keyfob too … the second time (with a replacement key) I managed to slice into the PCB … nightmare. I’d not recommend buying a Renault whilst they have flexi keyfobs like this – it’s almost as if they’re designed to fail…

  3. for anyone tempted to replicate this or even reshell their keys to a new fob case be aware a lot(most) of manufacturers have the immobalisers passive RFID element seperate from the PCB hurried somewhere in the plastic of the shell near the blade. if you lose this bit you have a car that won’t start. so tread carefully and do your homework :)

    im an auto spark, I get mibby a car or 2 a month where someone’s reshell a key using an eBay kit and accidentally thrown out the immobaliser chip. easy done.

      1. Open the door stand on you left hand while winding down a rear passenger window while pressing the horn and tapping out a binary string of the dictionary on the foot pedals while alternating the A/C between hot and cold and opening and closing the Glove Compartment at a rate of 40 open and closes a minute for 10 minutes.

    1. I absolutely hate how thick and long my Honda Keys are. And the remote is a separate fob that is just as thick as the key. Together they take up almost my entire pocket.

  4. I also dread the day when I’ll have to replace my thin metal keys with fat plastic fobs, so this could be useful. You could also use it to make a fob in the form of a toy car like some supercars come with.

  5. I was just thinking of doing this for my Honda, but for the remote start. Honda, in their infinite wisdom, did not make a key containing the regular key and the remote start, so I have 2 key fobs. The remote start is probably 50-60% THICKER than the already think honda key, and the buttons are kind of bowed outward and always get accidentally triggered in my pocket at work. But the car is out of range so it just beeps annoyingly.

  6. Why not just leave the buttons and let them poke up through a square hole in the frame? maybe cover with some rubber from an inner tube or something to keep it somewhat water resistant and snag free.

  7. “and generally spoils the lines of your carefully chosen outfit.” ..hmmmm.. I seriously doubt that most makers/hackers here in this blog would care too much about this kind of vanity. I’d much rather carry a domino in my pocket than a full size bar of soap but its not about vanity.

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