Wheel motor expansion card- A Truly Mobile Laptop

I had a silly idea of making an expansion card with a motor driven wheel under it. The idea is that then you could drive your laptop around with two of these cards placed on either side- making your laptop truly mobile, lol.

It could be a fairly straightforward Arduino project, and a python script that controls the wheels over serial based on Bluetooth keyboard input.

The wheels would have to be taller than the laptop to give ground clearance, ofcourse, but these tiny 6mm motors can probably fit within the chasis. To prevent the laptop scraping the floor, a castor wheel clipon would be needed as well.

I know it sounds pretty dumb, but even if ten people wanted it, I’d love to make it. I just wanna have the pun of a mobile laptop :laughing:

I made a google form to gauge the interest here

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I had a quick jab at the BOM:
Motor ~10$
uC (probably atmega32U4MU, same a pro micro) ~5$
Motor driver(probably PAM8016) ~0.5$
USB C connector ~2$
Passives ~1$
Plastics(3d printed case, wheel) ~5$

So, it should be possible to make this for <25$. You’d need two to do anything fun, of course.

I was thinking about this and wondering if there would be thermal issues. But thankfully the stall current on the motors <0.25A. Meaning at the full 5V(I’ll PWM the motors at 3V or less, but not sure about the switching losses on the H bridge, so let’s take the worst-case scenario) the max power loss would be 1.25W- easily air-cooled since the power would be spread across a fairly large motor+H bridge surface area.

Did some math on possible speeds the laptop can achieve. The motor power ~0.6W, with the mechanical gear train, we can easily expect 0.2W to be delivered to the wheel. We have two wheels, so 0.4W total.

The two sources of drag on the laptop will be friction on the castor wheel and aerodynamic drag. Neglecting the friction on castor wheel, and using this power to speed conversion formula with drag coefficient=1(laptop is NOT aero if the screen is open, lol), laptop area~0.3*0.25m~0.07m^2, air density 1.2kg/m^3 and using 0.4W as the power, we get max speed = 2.1m/s or ~7fps. Which seems kinda insane.

Needless to say, I’ll be limiting the speed to ~1fps to ensure the laptop’s safety and to account for friction on the castor wheel.

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Found a much cheaper motor here That might reduce the BOM by 8$. Ordered both types of motors. Should have them by Friday to test.

The major work in this project will be making the PCB and finetuning the assembly. So, I’m planning a proof of concept works-like prototype before I even open KiCAD.

It’s dumb, but can’t wait to see it working X)

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Sounds like a solid viral prank video to me. “My brother tried to open his new laptop and you WON’T BELIEVE what happened next!!1” Could be a good way to advertise FW to a new market segment?

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Why not use 4 wheels? All the bays? Then all four points of contact will be drivable.

And rig up a local web server for camera feed and remote control.

Any phone can connect to the access point the laptop is connected to, and connect to the laptop…

And to cut down on drag, nearly close the lid and use a small mirror to realign the camera with a forward view… But stuff could break it someone tried to close it…

But still, the other suggestions… Sounds like a pretty interesting video/?series?

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OMG! Hells yeah, you guys! I’m so glad to see you’re as excited about it as I am!

@jojoke13 you and me both!

@JPTiger I can totally see the tiktok, hahaha. I’m not tapped into the viral video world at all, but have some influencer friends. If the community feels strongly about it, I’d love to give it a shot. Why not!

@Ben_R I completely agree with the idea of using the camera feed. It might actually make for a really nice computer vision RC car platform for education. Move over raspberry pi, there’s an i7 in town.

I kinda like the idea of moving around with the screen wide open though. Leaves a lot of potential for displaying animations for fun. But the closed lid does offer a much more stable platform, less likely to topple over. The mirror could be housed in a 3d printed clip to prevent anything from breaking. In fact, it could probably be housed in the same clip as the castor wheel if it’s a two-wheel system.

I’m not sure the center of gravity will be under the wheelbase even if we use all 4 bays. But if the system is stable in that configuration, that’ll be dope.

Can I just say that I’ve been waiting for a modular laptop for almost a decade?! I remember designing an Arduino extension for my Lenovo that fit in the cellular slot back in 2013.

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Just had a look at the google form responses, and someone raised an important point which I’d like to elaborate on. You know who you are, please let me know if I should @ you here.

I’m all for Open-Source! So, whatever happens, the design files will always be free. The only reason I’d like to know what people would like to pay for it is to figure out what quantities I should be aiming for when choosing components. As you all know, it’s much easier and faster to make an expensive product and iterate the cost down than to try to make the cheapest product from the get-go.

/ to show my love for open-source, and a establish some street cred, here’s an open-source project I crowdfunded: Programmable-Air

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I got this 6mm motor in the mail today. Tested it out with a 4.8V supply and a single motor has plenty of power to drive around a surfacebook2!

Check out the test video here. I can’t believe hor much torque this tiny thing packs! Surprisingly, the higher gear ratio four stage motor has lower torque because the gears start slipping. Maybe I got a defective unit.

Anyway, I feel pretty positive about proceeding with PCB and CAD development. Would love to hear what you guys think!

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This idea reminds me of some of the WiPhone ideas they showed having two drive wheels on the phone.

Not sure how much I would use these expansion cards, but I love seeing the ideas that others come up with.

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Hi @MduBois , and welcome to the community! I had the same idea for an iphone as well, haha. Would love to see a link to the wiphone if you can find it. Cursory search didn’t reveal it.

@Amitabh_Shrivastava Thank you for the welcome :slight_smile: I just ordered my Framework DIY edition, and I am eager to get into it.

I believe the WiPhone is being shipped out now. They have an image/video on the landing page that shows the features and possibilities of the phone. You will see the phone driving around in that graphic/video. As I said in my previous post, reading this made me think of the project I mentioned. I look forward to following the development process.

I would love to have this. It doesn’t matter that it’s dumb. It’s cool and funny and that’s all that matters.