Matchbox Car : Smallest motor and wheel pwm controlled

Hi All.

I’m very loosely thinking I need a small robotic matchbox car.
This will be a late 2024 early 2025 goal.

I’m usually a big fan of the: terrible idea, try it, fail, slightly better idea loop.
I don’t think that’s how I want to approach it this time some I’m hoping someone can point me towards the right components.

If you wanted to drive and steer a car that weighed < 100g with wheels that where no bigger than a 5 cent echidna what would you you use? Hoping for something PWM controlled.

Any thoughts?
@Jaryd where you at?

Pix :heavy_heart_exclamation:

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Hi Jonny,

Sounds like a siiick project!

If you wanna go small the best way is likely a custom PCB.
That way you can add your micro of choice, I’d go for one of the newer ESP32 modules, S3 or C3 depending on pin count.

A motor driver IC, some of those 6V micro motors (pololu sell some, gearbox or no gearbox they’re the ones I’d go for)
Then a small lipo or 18650 me thinks

No kidding!
Promising recommendation.
I’ll look into it :slight_smile:

image

Whoah! Maybe if it was a semi trailer

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Suitable motors do exist. Your best source would be an older-style camera that makes a whirring noise as it auto-focuses. These typically use a small low-voltage DC motor.

20240407_081724

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Hi All,

Kimmo - definitely had a different scale in mind ahaha

Jeff - How do you come up with such amazing suggestions on parts?

And another idea… Why not take apart and study something that already exists? I saw something similar to these in Jaycar or Dick Smith a while ago I guess: 1/58 2.4G 4CH Electric Mini RC Car w/ LED Light Radio Remote Control Racing Toys | eBay

Would be good to salvage the motors and maybe battery atleast?

The smallest weight battle bots are also something worth looking at if you wanna go that scale up but adding a lot more oomph

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This may interest you.

I have one of these and for dimension sake it will fit into a box 21x24x10mm.

Roland

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Ah Mr Pix, sorry I haven’t had much time to venture onto the forums these last few weeks.

This is a big coincidence because I’ve been looking at building a little drift RC Hot Wheels car the last few months and have gone down the rabbit hole on YouTube. If you punch in “rc hotwheels diy” you’ll find a lot of build guides.

They all have basically the same components. Either a small receiver with a remote transceiver or a small form-factor ESP32 for control. For the steering, they usually solder up their own steering system out of some small wire, and have a 1.5g linear micro serv to control it (these things are TINY). And for the drive motor, I’ve seen a lot of people take the small DC motor out of a 9g servo and connect the rear wheels directly to it. Then using some small transistors you can make a tiny h-bridge to drive it."

This is for a tiny little Hot Wheels-sized car, becomes very difficult to make things at this scale, a little bigger and I imagine it would get easier.

Sorry for the late reply, hope this helps though, keep us in the loop what you make!

Jaryd

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Hi Jaryd.

Thanks for your thoughts.

This is what I’m learning.
I think this is the wrong “first project” idea.
Too many new challenges for someone who has never worked with motors before.
I’ll leave this for now, and maybe come back to it one day.

Pix :heavy_heart_exclamation:

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