8th grade is old enough to do just about anything. I like to do big memorable projects with my kid where we both have to learn some things along the way. I’d build a go kart at this age, or some other electric motor driven vehicle. I’d think it would span a few months depending on time dedicated. And covers mechanical, fabrication, components and even some programming if you want to tune it yourself.

Also, I like to reinforce the concept of “dreaming it up”, tell my kids to think of a thing to make and we break down the steps we think are needed to build it. At first, it’s like their imagination wasn’t big enough. They’d have an idea and I’d show them how we could build it pretty easily. Now, it’s gotten to where they know the skies the limit and anything of kind of possible so they start big and then work their way back down to a realistic scope of features. All to say, ask your kid what they want to build!

I loved doing chemistry experiments and demos at home as a kid. I had books like the Golden Book of Chemistry Experiments [1] but this is a modern guide that I would gladly recommend:

Illustrated Guide to Home Chemistry Experiments: All Lab, No Lecture by Robert Bruce Thompson

https://www.amazon.com/Illustrated-Guide-Home-Chemistry-Expe...

[1] https://library.sciencemadness.org/library/books/Brent_GBC.p...

GNU radio is an awesome signal processing toolkit. You can use it to take signals from a cheap RTLsdr, or even a microphone, and make new virtual instruments, radios, etc. Long ago I was interested in aircraft navigation aids, and was able to throw together a receiver for the local VOR transmitter, which showed me on screen where I was relative to the transmitter.

You could build a sonar system, listen to ultrasound, or almost anything you can imagine, thanks to Moore's law and the massive amount of compute we have these days.

I think pen plotters are really cool! There's a bunch of models on 3d printing websites like this one: https://www.printables.com/model/573473-pen-plotter-core-xy

If he likes video games, we’re hosting a big game jam for middle and high schoolers next weekend.

It’s free and nonprofit. There are 60 locations. Maybe one is near you?

https://counterspell.hackclub.com/

Buy a Bambu Lab A1 Mini 3D printer. They're amazing. Then look at examples of what you can do on Youtube. Amazing! Kids nowadays have it so good.

If I had kids, I would probably subscribe to KiwiCo (https://www.kiwico.com/us/store/cp/12-plus-years-old).

Lego?

Unfortunately, my limited (geographically-constrained) contact with my nieces and nephews has severely impacted my ability to influence them towards technology. :(

Exposure is one thing that is helpful, but in the end, you have to find something that your son is so enthralled with that he wants to pursue it on his own. It begins with curiosity about something, of course, but ultimately requires him to develop the skills and then the confidence to where he wants to begin doing things on his own.

The problem is in the things that parents subject their children to that actually drive the children away from those things... like piano lessons! (I say this as a pianist that has taught many children over the years, and it's obvious which kids are being forced.)

What does he like to do?

Perhaps it's too simple, but I like https://elenco.com/snapcircuits/

Around that age I built a trebuchet. Did calculations, got some plywood and building lumber, etc. Had a lot of fun chucking water balloons down a hill.

I'm a really big fan of the more modern way of doing things.

A lot of old school maker projects are fun, but they're also basically E waste making kits now that phones do almost everything.

Not having a bunch of low tech gadgets laying around is really nice, they can easily become the biggest clutter challenge in a space, the same way paper used to back when more people still used it for things other than books.

Building a small solar energy system is fun and easy, and also practical.

3D printing is fantastic.

Meshtastic has a lot of DIY and learning potential and is like the lite edition of ham radio. What's really cool is that range testing gets you outside.

Maybe design something together with JLCPCB and have it made(Leave off any through hole connectors and solder them yourself for both fun and pretty decent cost savings).

You & he might get inspiration from Low Tech Magazine, https://web.archive.org/web/20240122052820/https://solar.low...

My father is an electrical engineer. Growing up, he had countless components in the basement, including a whole slew of 7400-series DIP chips, as well as a bunch of (powered) breadboards and spare wire. In highschool I had so so much fun building things from scratch - I recall building a basic adder by drawing out the truth tables and doing boolean algebra to come up with the circuit diagram, eventually evolving it into a more fully-fledged calculator. It felt (and still feels) like magic! Most of it was self-directed, though I certainly got his help in a lot of places.

I think sort of "choose your own adventure" projects like that are great, and they also force you to really understand everything you're doing. You can also scale the scope of the "project" to whatever you want; it can even be a sort of iterative process. More importantly (imo) you're left with a bunch of components that he can tinker around with endlessly :)

Adafruit has loads of projects and kits like TV-Be-Gone, Circuit Playground, EdgeBadge and others. They're suitable for a range of ages and experience levels, usually come with lesson materials and are generally pretty affordable.

I believe SparkFun has a similar ecosystem of products and projects as well.

I'm not affiliated with either of these companies.

It might be a good idea to discover what your kid is really interested in. It is a common trap for adults to project their unfulfilled childhood desires onto their children. It used to be fathers buying and building model railways which the kid ignores and chooses to go outside and play football.

Aolean harp! I'm planning a workshop for kids around this now: build the harp & resonator however you like (two flower pots with a piece of fishing line in between for example -- more ideas here: https://www.homemade-dessert-recipes.com/aeolian-harp.html) then add a contact mic to the resonator and do some simple digital processing (delays and phase shifts) on the waveforms to demonstrate signal arithmetic and the basics of acoustics.

I soldered one of these with my 6 year old: https://thepihut.com/products/3d-xmas-tree-for-raspberry-pi. They seem to be out of stock, but maybe you can find them somewhere else.

Fun, quick project. With my kid, I healed the iron and they held the solder. I’m guess a 13 year old could do more (or all) themselves.

Then there are options for tweaking the program, like different patterns, a “count down” to Christmas, etc.

FIRST Tech Challenge

13 year old can do almost anything. Only problem is ... scope, I guess?

Like, I was making games in Visual Basic. Made a little Tyrian clone. It had total of two levels :D

Crunch Labs of Mark Rober https://www.crunchlabs.com/ https://www.youtube.com/@MarkRober

Fpv, my kid didn’t care about the sdr rtl plus it doesn’t actually do any interesting frequencies. Everything interesting is 1ghz and above these days

For the drone I just bought the parts over time and one day he asked if he could put it all to put it all together. It was a bit of a bitch debugging his mistakes but I’m glad he took an interest and applied himself

Take a look at what these guys do:

https://circuitmess.com/

Buy a $20 RC car off Amazon and replace the radio receiver with a raspberry pi for a quick and dirty driverless car platform. Might have to do some surgery to reuse the motor drivers or you might have to add your own, but it's generally not too bad.

Build a cigar box guitar.

Here's my method: https://jsnow.bootlegether.net/cbg/cbg.html

Not quite the same, but if you've a leaf blower, then making a hovercraft with a couple of pool noodles and a circular piece of plywood is pretty cool (and a lot of fun).

1. Has Motor, Flames or both 2. Slightly Dangerous 3. Desire to make it better

The key is to spark something that creates an obsession IMO.

Raspberry Pi CAN Bus trains kids in reading diagnostic logs

https://www.autopi.io/blog/raspberry-pi-can-bus-explained/

This is a great way to get Linux experience. One student used these skills to work on Medtronic GI Genius via YOLO AI.

Rebuild a used car. They can drive it in 2 years when they get a learners permit.

BBC Microbit project kit. Awesome stuff. It's used in secondary schools here in NL to teach kids CDT.

Custom handwired (maybe with amoeba pcbs to help) keyboard, there are a lot of designs out there.

I think 8 grade is too old to make silly toys, and time to do some serious stuff:

1. Carpentry project

2. CNC machining project

3. Microelectronics: assembly from ready parts

4. Drone or aviation related project

if he is into computer stuff, just teach him how to hack computers and websites, the pentesting stuff.

diy telescope.

You can get a mirror set very cheap on ali, eg https://www.aliexpress.com/item/1005005098614936.html

You'll need to buy an eyepiece or two, and hardware, bolts, etc, but everything else can be made or 3d printed.

I designed and made, with my kids, a 76mm 'cheapscope' using PVC pipe, 3d-printed mirror-holder, spider. focuser and camera-tripod connector, here: https://imgur.com/a/cheapscope-4KtPgoN

I meant to post the 3d-print designs but haven't got to it, let me know if you're interested.

For sure it's not the best scope (or design) ever (and the 3d prints warped a bit), and no phone/camera eyepiece mount so the pictures are shaky, but it works, it was fun, and opens up a new world(s).

Modular synthesizer.

8th graders need to make noise.

Good luck.

Sometimes a 13 year old kid just wants to be a kid. I know because I was robbed of that, thanks to the adults in my life growing up. Let your kid discover whatever it is that they are into, on their own.