As someone who's built both BattleBots and Professional Robotics for work, BattleBots is a great way to get out of equations and hands on fabrication, manufacturing, testing, and scrappiness that is so hard to reach in mechanical and electrical engineering. And unlike FIRST or Lego robots, it's much more open ended and "guardrails off" engineering, which I found really freeing from the tyranny of academic-style competition robotics. You can still incorporate all the sensors and algorithm-stuff (many folks build their own motor controllers like "brushless-rage" or have sensors like Chomp), but if you just love seeing things move and love mechanical design, it's a great thing.
For BattleBots in particular, the easiest way to get into it is to find some guides online for a simple bot[1] with DC motors and a 3D printed body, and just enter it into a local combat robot competition! You'll learn the basics of a motor, speed controller, selecting wheels and other interfaces, as well as designing a chassis and fabricating it. At a competition you get the thrill of the fight, and afterwards you can sweep your robot scraps into a dustpan, make friends with other bot builders and go from there.
[1] A quick search on instructs Les and I found this, though there are many more great robot tutorials: https://www.instructables.com/Naked-Singularity-Beetleweight... . Here is one that overviews all the basic steps in a BattleBots https://www.instructables.com/How-to-design-and-build-a-comb...
Mark Rober has a new product where they ship a new robot every 2 months. They give you the basic instructions on how to build/program it but the idea is that you take that knowledge and then expand on it yourself by adding features. My daughter is still a little too young for it so I haven't used it personally. The biggest issue is that it is a subscription and not a one time purchase.
Here is the link: https://www.crunchlabs.com/products/hack-pack-subscription
And here is a brief video explaining how it expands beyond the normal "premade robot kit." https://www.youtube.com/watch?v=TtdOdUi9b_s
Doing something similar at home is very possible, and if you are nearby an existing team or program they are usually more than happy to have a conversation with parents about how to get their kids started even if it doesn't mean joining the team.
https://en.wikipedia.org/wiki/Lego_Mindstorms
but is is discontinued. In terms of easy of build and programming these were great. This kit is still available
https://education.lego.com/en-us/products/lego-education-spi...
https://upperstory.com/en/spintronics/
This is more about learning about electicity in a tangible physical way, using puzzles to learn -- so it's maybe a level lower than your intent, but it is for kids 8 and up and seems like even adults could learn quite a bit from it.
It's really hard to describe though - I strongly recommend watching the video at that link or at least looking at a picture.
You buy a relatively affordable kit of parts, but then you are free to assemble and program the bit in whatever way imaginable.
VEX annually comes out with new games and challenges for your robot to be able to complete. There are teams and clubs across the US, and it’s an all around great program.
I’m looking forward to my kids being old enough to build and compete, It’s a blast for kids and adults!
https://education.lego.com/en-us/products/lego-education-spi...
https://github.com/hrc2/blossom-public
It's basically a floating head that others have customized with more functionality (e.g. cameras, microphones, screens, control with a phone) for research applications in human-robot interaction (education, telepresence, an assistant for ADHD task-focusing and CBT). We ran ~90 minute bot-building workshops for middle schoolers; they all successfully completed their robots and seemed to enjoy the hands-on experience.
It gives you an accessible starting point, but is a fully featured programming language and has a variety of sensors, motors, etc which can be made into increasingly complex and diverse robots.
A few words of advice from someone who has been dabbling for a decade or so, but never really managed more than some half baked prototypes and a few kit builds. You need to consider these three trade offs: time, skill, and money.
Time: If you have a lot of time, you can learn what you need to learn to build a robot. Learn 3d modeling/printing to make a chassis (my local library has a 3d printer if you don't want to buy one). Learn how to piece together microcontrollers, motor controllers, BMS, and sensors, etc... And learn how to program everything to work together.
Skill: If you already are pretty good building things, programming, etc... you can leverage those skills. For a robot chassis, it can be done with things around your house, but you need to have the skills and a bit of creativity to make a good one. If you know the arduino ecosystem pretty well, you can pretty easily put together a prototype board, etc...
Money: You can buy a prebuilt chassis, or a board that has integrated motor controllers and BMS, etc... This will save you time and you will probably end up with a nicer end product than what you could build yourself. Of course the more you lean into this, the closer you are getting to a kit build robot. And FWIW, a kit robot is probably going to be cheaper than mixing and matching prebuilt components + some DIY.
Also, it kinda depends on what you want to do. Do you just want a little robot that drives around the house (cheap and easy). Or maybe does some line following (also easy). Or do you want a self-balancing robot, or a robot arm (a bit harder and more money). Or something really fancy like a self landing model rocket or a self driving lawn mower (expensive and difficult). You will probably want to start with the easy stuff first, just so you can get a feel for it. And then move up the difficulty ladder from there. But from my experience the time/skill/money trade off goes up fairly exponentially. Getting a half baked prototype for a simple rover is a weekend long project. But doing something really sophisticated or polished is months/years of effort (unless you want to drop some coin to speed things up). It is a fun hobby, but it does require a bit of investment before you start getting impressive results. If you think you and your kid are up for it, then dive right in. But if you think this might be more of a short term curiosity, then a kit or something similar is probably your best bet.
You might learn Fusion if you want to 3D model the chassis - again, everything is on Youtube.
Good luck!
Once you understand how transmitters/receivers work and what servos and speed controllers do then you can construct a chassis. The speed controllers would drive the motors moving the robot around and then a servo could open the valve on a flame thrower or something...
They key is understanding the radio control tech first.
First off, are they interested in the mechanical engineering and fabrication challenges? Or more interested in the behavior and controls challenges? Because you may chose a different path. At one point I regarded battle-bots as just an RC car with a bad attitude. But I have to admit that there are a lot of interesting mechanical design challenges to be solved. Melonee Wise did battle bots... and went on to co-found Fetch and is now CTO at Agility, so it can certainly lead to interesting things.
If more interested in behavior and controls challenges, then maybe you don't want to go the competition route at all, but want to make up a "challenge" and build a robot to target that. Like build a robot that can patrol your house, and take pictures of all the doors. Kind of a "security robot" (but not really all that useful) but I guarantee you will learn a lot attempting that. (In fact, that is probably too much for a first challenge.)
Lego Mindstorms has a lot going for it, but ultimately becomes limiting. Definitely not a bad place to start with a 10yo, but expect to move on.
Pololu and SparkFun have a lot of interesting modules, Pololu last I looked also had some basic platforms that make a good place to start. Also, depending on where you live there may be a good robotics club to join.
What makes it better than (eg) Micropython on cheaper hardware the Blocks programming language. She had some experience with Scratch before and the libraries for this are great. The built in led matrix and sensors are useful and the radio is nippy enough for remote HCI.
There are quite a lot of accessories available from a few different manufacturers. These can minimise build time and let you focus on programming, but you can DIY. I think there's even a Lego breakout.
I will add, this has been a gateway hobby for me. While she's learning, I'm learning and I'm using my C and Python experience to have fun with really cut down boards. It's fun but you end up making a hell of a lot of "oh it's just £10 for a pack of motor controllers, MOSFETs, resistors, caps, etc etc etc." It's endless.
Maybe buy Lego Mindstorms and Lego Technics for home and when the kid runs out of ideas, give them challenges like a line-following robot or a FLL course.
Then move to a FreeNove Ultimate Sarter Kit. I prefer the Arduino Uno based kits, but the ESP32 kits have their place as well.
But as soon as you actually want to build the thing you need to work out what your end goal is, how it is physically put together (lets call that the chassis), how it is going to mechanically move, how you are going to drive that movement and how you are going to control that driving method, and then how abstract it needs to do (are you telling it what to do, or telling it what end goal to pursue?).
Starting with Lego, or perhaps meccano will let you build the physical thing, maybe even have it move with a remote control. You'd get the plastic (Lego) or metal (Meccano) parts as-is and you build whatever you want. Add a two motors and you can drive wheels and steering. Add a receiver and a remote and you have your remote controlled vehicle.
Edit: fischertechnik is another brand that makes parts you can assemble in whatever way you want (some random YouTube Hit: https://www.youtube.com/watch?v=yVzK3VaYxS8 ), it apparently has something that also lets you go to PLC levels of robots controllers: https://www.rapidonline.com/fischertechnik-robo-tx-controlle... . This is of course not what you'd pick if you also wanted to build the entire controller.
But when you don't want that plastic or metal ready made, and you don't want modules that deal with motors or controllers for you, you now also need to learn some metal working, electronics (microcontrollers, RF transceivers, power management), and software (those microcontrollers won't program themselves).
Maybe starting with a kit isn't such a bad idea, and then going up a level at a time (i.e. tackle some of the software, or maybe mechanics) and getting to see the results of your work is a good thing, rather than trying to learn everything at once.
The reason I say is this. Robotics is at the juncture of programming, electronics and mechanics. Learning robotics from zero is learning all of these 3 simultaneously and in a frustrating way. It is frustrating because, real world stuff breaks/faulty parts, misaligned parts, buggy firmware etc. Suppose you want to give a simple instruction move forward 3 seconds, turn right, move forward 2 seconds, but real world stuff has misaligned wheels, it wont turn exactly 90 degrees, it varies between servors/motors of the same model/make, there is jitter etc etc. So many fine-tuning and adjustments you have to make in the real world, and that takes focus and interest away from the creative fun part.
So my suggestion would be learn programming, learn a bit of electronics with age appropriate kits etc, before combining them to robotics.
An iPhone app is used to teleoperate the arm and gather examples of an action. You then train the model and deploy it and the arm performs the actions based on current camera input and joint angle state.
It's a FOSS robotics software toolkit; you can model the entire robot and simulate nearly every aspect (including physics and servos and whatnot). Using it you can design, test, print, and assemble in a relatively nice fashion.
I mostly use BowlerStudio for 3D printing CAD stuff, but it does a lot, and since it's free I think it's worth playing with.
This setup gives you pretty much all the possibilities of Mindstorms at a small fraction of the investment
If your child has experience with Scratch, then MicroBlocks will make him feel very familiar.
I’d do a web search for “sumobot arduino” and go from there.
You could then pivot from this by reusing the code you've already done and switch over to custom circuitry.
Am not sure how it compares to Mindstorm but I'd suspect they haven't held their value used in the same way as Lego products tend to.
A snap-together kit built RC car is the best way to teach servo control, motor ESC, and basic battery handling concepts.
3d printer kits like Voron or Prusa is the best way to learn stepper motor motion platforms. The FreeCAD/CAM workflow is identical most CNC gcode based machines.
The cheapest introduction to electronics theory is a Ham radio license. This will answer how RF remote controllers work, and develop an intuition about EE design.
Get a bulk pack of Arduino hobby boards, resister pack, and LEDs. This allows you to bring together all these bits to solve robotics problems.
Building a turtle bot is super easy with the above skills.
Remember to have fun, =3
I found one called VinciBot that looks kind of interesting - https://www.youtube.com/watch?v=BftyB954_r4 I like the fact it can draw (it doesn't look like it can pick up the pen by default though, but it appears to have a motor inside that you can attach Lego components to).
I installed their android app to have a little look at it.
[1] https://shop.teamwitchdoctor.com/products/camp-witch-doctor
Then maybe robotics kits and such.
I prefer to learn how everything works and build something custom instead of just buying a premade kit and following instructions.
Together is probably your child’s preference. A premade kit goes straight to the building phase. And kits are something they can undertake theirself as they pursue independence in two or three years.
You are launching a person. Good luck.
for about 2k, you can make a robot that can clean your house and is probably smarter than a dog/cat
My path: Chinese 3 wheel chassis, Arduino and I2C color sensor. Line follower robot to be extended to multiple color sensors. It sounds easy, but it will occupy you with your sine for few weekends. Afterwards you’ll see what part is most interesting for your son. Bigger robot, bigger processor, bigger wheels, more speed, a camera instead of color sensor. Maybe just cool paint.
Good luck with your project!