There are only so many hours you can keep doomscrolling before your brain is on the brink of an explosion. If you’re looking for a more constructive way to pass time and entertain yourself, check out some of these do-it-yourself engineering and science projects.

Each of these DIY projects and kits leaves you with something pretty cool to show off — from a robot arm that can handle your repetitive tasks to a drone you built yourself. There’s a project for just about everyone, regardless of age and budget, and most are even on sale. As a bonus, for those with kids, you might even inspire them in the process. They won’t even realize they’re doing something educational.

SunFounder Nano DIY 4-DOF Robot Kit

Gain foundational robotics and coding skills by building your own adorable Sloth robot that’s compatible with the included SunFounder Nano board or an Arduino Nano board. It has two legs you can program to walk, kick, and dance, and a module that allows it to detect and avoid obstacles. Usually $59, you can save 21% and get it on sale for just $46.95.

Credit: Sunfounder

SunFounder Nano DIY 4-DOF Robot Kit

$46.95 at the Mashable Shop

SunFounder Robotic Arm Edge Kit for Arduino

Designed for DIY electronics hobbyists to learn robot arm control, the SunFounder Robotic Arm Kit uses an open-source MCU Arduino UNO and a servo expansion board to move, pick up things, tackle repetitive tasks, and more. Save 21% and bring home this kit for only $54.99.

Credit: Sunfounder

SunFounder Robotic Arm Edge Kit for Arduino

$54.99 at the Mashable Shop

DIY Drone Builder Kit

Flying a drone is much more satisfying when you build the drone yourself. This DIY kit by Electroninks allows you to draw your own circuits onto the drone arms using Circuit Scribe pens, snap the drone hub and motors into place, and soar through the skies. Take 69% off for a limited time and pay just $29.98 (regularly $99) for the full kit, including the compatible app for free.

Credit: Electron Inks

DIY Drone Builder Kit

$29.98 at the Mashable Shop

DIY Coding Kit for Ages 9 to 12

Built for kids ages 9 to 12, this DIY coding kit is designed to help kids build critical thinking and coding skills through hands-on playful learning. The Arduino-based Twin Science coding module connects to the Twinner app so kids can experiment with block codes to operate it and tackle different kinds of projects. Get the full kit for $84.90.

Finger using coding app on tablet screen

Credit: Twin Science

DIY Coding Kit for Ages 9 to 12

$84.90 at the Mashable Shop

DIY Building Block STEM Drone

Featured before, this DIY drone teaches kids ages 6 and up the basics of aerodynamics and load balance, while enhancing practical skills and confidence. With step-by-step directions, kids (and kids at heart) can build a drone that uses UAV technology for a smooth flying experience, can do 360-degree stunt flips, and more. Save 61% for a limited time and get the kit for $49.99.

White drone with see-through body showing wiring

Credit: Electronic Avenue

DIY Building Block STEM Drone (Grey)

$49.99 at the Mashable Shop

Metal Vehicle DIY Model Kit

With a combination of polished stainless steel, artificial leather, and a smooth, glossy surface, this DIY Bentley Speed Six model kit can serve as luxury decor when you finish building it. It comes with 146 pieces for a quality build and can even move on its own with the flick of a switch. Get the kit for $119.95 for a limited time.

Credit: Time For Machine

Metal Vehicle DIY Model Kit

$119.95 at the Mashable Shop

Petoi Bittle: Palm-Sized Robot Dog

A Kickstarter success, this palm-sized robot dog (which we featured before) is highly programmable with Scratch, C++ and Python, and is highly extensible with Raspberry Pi and Arduino. First, assemble its body like a puzzle, then download demo codes on GitHub and experiment with its creepy-cool Boston Dynamics-style motions. It’s on sale for just $299 for a limited time — that’s $30 off its usual cost.

Credit: Petoi

Petoi Bittle: Palm-Sized Robot Dog for STEM & Fun!

$299 at the Mashable Shop

Petoi Nybble: Cutest Open-Source Bionic Robot Cat

Fear not, cat lovers. You, too, can build your own robotic animal with the Petoi Nybble open-source bionic cat. Also highly extensible and programmable, you can teach your robot cat actual cat-like behaviors and tricks once you assemble it. Save $30 and get it on sale for $249.

Credit: Petoi

Petoi Nybble: Cutest Open-Source Bionic Robot Cat

$249 at the Mashable Shop

Remote and App-Controlled Robot Building Kit

This two-in-one kit features 901 pieces that can be assembled into a tank robot or racing car, sort of like a Transformer. It’s suitable for kids ages 8 and up and can inspire early learners to explore coding concepts and build STEM skills. Slash 48% off and get this DIY kit for just $148.99.

Yellow transformer robot in car and robot mode with controller

Credit: Ineedmeone

2-in-1, 901 Pieces Remote & App-Controlled Robot Building Kit

$148.99 at the Mashable Shop

Microscope Science Kit for Kids

Designed to help kids explore science and nature, this microscope can be used as a handheld device, as a vertical scientific scope, and for photo-sharing by connecting to a phone. It’s also easy to operate and has a magnification of up to 60x-120x. Usually $108, you can save 49% and snag it for only $54.99.

White and green microscope with slides and box

Credit: Ineedmeone

Microscope Science Kit for Kids

$54.99 at the Mashable Shop

STEM Robot Toy for Kids Building Block Kit

This DIY RC robot kit is a fun way to help your kiddo build critical thinking, STEM, and programming skills. After building it alongside the step-by-step guide, it can be controlled with a remote or an app to move forward/backward, left/right, or in a full 360-degree rotation. It’s on sale for 49% off for a limited time, knocking the price down to just $84.99.