About: My name is Randy and I am a Community Manager in these here parts. In a previous life I had founded and run the Instructables Design Studio (RIP) @ Autodesk's Pier 9 Technology Center. I'm also the author ...

LieDar is a fake lidar sensor that you can attach to the top of your car to instantly turn it into a self-driving vehicle. Whereas some companies have spent millions of dollars developing the technology to have conversations about the future of transportation, you can butt in for a mere fraction of the cost. To join the multimillion dollar conversation all you need is a 3D printer, and a little gumption.

When your car sports fashionable technology you can experience first-hand what it is like to be a leader in innovation. Everywhere you go people will stop dead in their tracks in wonder and admiration. Children will look back and remember the day they first encountered a self-driving car -- your self-driving car! Overnight you can go from merely being a terrible driver to a well-respected and beloved ambassador of the future.

Impress your neighbors. Meet new people. Become more attractive to members of all sexes. Own the road! The LieDar can do all of this for you and more. Retrofit your car today!

Step 1: Get the Parts

You will need to get:
(x1) 12V geared motor (the geared motor I used was surplus and no longer available)
(x1) D-battery holder (can put two in parallel for more dependable results)
(x1) D-battery
(x1) 3/8" i.d. shaft collar
(x5) 3/4" x 6-32 nuts and bolts
(x1) 1-1/2" x 6-32 bolt
(x1) 30-nf 3M contact adhesive
(x1) Disposable paint brush
(x1) Roll of painter's tape
(x1) Krazy glue

You will need to 3D print:
(x1) LieDar Top and Rubber Cover (printed as assembly - 1 piece - using an Objet)
(x1) LieDar Top Plate
(x1) LieDar Base (model needs to be modified to accommodate your motor)
(x1) LieDar Base Plate
(x1) LieDar Front Insert

You will need to acquire and/or (laser) cut:
(x1) 4.725" x 6.3" x 1/8" radiant acrylic panel
(x1) 4.725" x 6.3" x 1/8" translucent acrylic panel

Step 2: Acrylic Cover

Tape along the outside of the clear acrylic panel and the front insert, leaving 1/4" of surface area exposed along the outside borders.

Brush on contact adhesive and wait for it to dry. Once dry, peel the tape away.

Line up the two objects perfectly and then stick them firmly together.

Step 3: Radiant Backing

Cover the back side of the front insert  in contact adhesive.

Cover the outside of the radiant acrylic panel with contact adhesive.

Wait for the contact adhesive to dry and then stick the two together.

Step 4: Install Fake Lens

Cover the inner rectangular frame of the top assembly with contact adhesive.

Also cover the edges of the lens assembly and 1/4" of the outer border with contact adhesive.

Wait for it to dry.

Put the lens assembly inside the top assembly, and then push it firmly into place.

Step 5: Insert Motor

Push fit the geared motor into the base assembly.

I left a few bolt holes around the edge of the motor in case I needed to attach a mechanical bracket to hold it firmly in place. I ultimately found this unnecessary.

Step 6: Prepare the Top Plate

Insert your shaft collar into the opening in the top plate. Make certain that the set screw is facing outwards so that it can be tightened.

Step 7: Connect

Push the top plate down onto the motor shaft such that the bolt hole in the top plate lines up with the split in the motor shaft.

Insert a 1-1/2" bolt through the bolt hole such that is passes through the split in the motor shaft.

Finally, fasten the top plate in place by tightening the set screw.

Step 8: Connect

Pass a bolt through the hole on the underside of the top assembly. Place a little crazy glue on a nut, and then twist it onto the bolt.

Pull up on the bolt, until the nut is pressed against the inner lip of the top assembly. When it seems like the glue is dry, untwist the bolt from the nut, leaving the nut glued in place.

Repeat this process for a number of the mounting holes.

When done, press fit the top plate in place, and then twist the bolts into the holes that have mounting nuts.

Step 9: Solder

Wire the red wire from the D-battery holder to one terminal on the motor and the black wire to the other.

To give your assembly a little more "umph" and ensure consistent operation, you can wire the battery holders in parallel (red wire to red wire - black wire to black wire).

Also, if you later decided that you don't like the direction the top assembly is spinning, just reverse the wiring to the motor and it will spin the opposite direction.

Step 10: Battery

Insert the battery and the base should start spinning.

This makes the next task a little trickier.

Step 11: Close

Install the base plate by lining up the top and bottom mounting fixtures and pressing the two together.

Screw bolts into the central mounting fixtures.

It helps to lift the (upside down) top part off the table so that part is spinning instead of the base part. It is hard to screw bolts into a spinning object.

Step 12: Now What?

Now you need to figure out a way to affix it to your car.

FAT Lab mounted this using an impromptu roof rack made of PVC, particle board, and ratchet straps. I recommend doing something a little classier if you have the time and the means.

Happy Self-Driving!



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    23 Discussions


    1 year ago

    Very cool! But I don't know if it's allowed by law, that attach external components outside a car.


    3 years ago

    donut in front of google is bold, i will give you that!!

    Chris F

    5 years ago

    I must be retarded b/c i dont get this thing at all. How is this car supposed to be able to "drive itself"?

    1 reply
    mchau2Chris F

    Reply 3 years ago

    agree, how was the car moving with their hands in the air?


    4 years ago on Introduction

    Very nice, but how are you going to pass it off as a self-driving car when there is clearly someone behind the wheel? :-)

    If affixing the text 'Google self-driving car' is all it takes, then the liedar isnt really necessary anymore :-)

    Still, a nice prank


    5 years ago

    I made this and it really works. I did modify it to beep a buzzer and to automatically switch to manual human control in heavy traffic. I can't wait to take it out of New York City and test the self driving capabilities. Man, that buzzer is sure annoying.

    Patrick S

    5 years ago on Introduction

    This always cracks me up. What fun it would be to drive around like that. Awesome as always.


    6 years ago on Introduction

    Nice job on the fake scanner, but a little more (well, actually any) detail on how the rest of the prank was pulled off would be more instructive, but as it stands your 'ible is entertaining and inspiring.  ☺


    6 years ago on Introduction

    I want to do this to my car! How do you pull of the self driving illusion though?


    6 years ago on Step 12

    This will make the cops taking notice alright! How much in fines...................?


    6 years ago on Introduction

    Cool concept and sorta fun. The entire video would have been so much more enjoyable if it wasn't for the horrible, horrible music that made it necessary to mute the sound and miss what was being said. Sometimes generic or instrumental music is best when teaching a concept.


    6 years ago on Introduction

    I'd recognize that laugh, in the end, anywhere. Funny!


    6 years ago on Introduction

    like the gif on step 12, nice touch ,
    if you dont have a 3d printer in the kitchen cupboard you could modify this .
    get good at the steer with your knee technique, and paint the edges of a piece of acrylic to look like a kindle ,
    or just get a dog in a high-vis vest on the passenger seat


    6 years ago on Introduction

    Good the "driver" is sitting in the car as a passenger. Suppose you want to go to park, it doesn't help to let the car drive itself to the park and you stay behind. This sounds extremely useful for people who can't drive themself? Can this also be a two-edged thing, taken advantage by some bad guys?
    What about the name "LieDar"?


    6 years ago on Introduction

    Randy, this is awesome and I love your design process as always. But I can't help but think the "self driving" image falls short once other drivers look in and tell immediately there's another person on the road.

    When building this project, how should one attempt to conceal oneself from the views of others?

    3 replies

    hilarious but how did he control the car at the time, did he have something wired into the steering and accelerator otherwise he would be seen where his hands touched the wheel and where his feet touched the pedals. your idea is great, perhaps use it to blame the car if you crash.