What is the Difference Between Reaction Wheels and Gyroscopes?

AD: To sign-up and get 91% off all yearly plans, go to https://www.hostinger.com/bruton and use my unique coupon code ‘BRUTON’ I’ve built various balancing robots in the past. These include two-wheel balancing robots like my Sonic the Hedgehog robot, and my one-wheel balancing robot which used an active two-axis omni wheel to balance on a single point. These robots actively move in the direction they are falling in order to catch themselves and balance. I also experimented with gyroscopes which use a constantly spinning mass and the resulting gyroscopic precession to exert a force and balance. A physical spinning gyroscope will exert a perpendicular force when it’s tilted in one axis. This means that if we actively drive the gyro in one axis, we can actively control the force in the perpendicular axis. This is called a Control Moment Gyro, and these have been used commercially to stabilise boats. Using an Inertial Measurement Unit to measure the angle and a PID controller to control the active tilt, allows us to balance a device on a single edge, and I made this work quite successfully with a two-wheel in-line balancing robot, as well as the one-wheel robot which balances like a two-wheel balancing robot in the other axis. These machines had two gyroscopes spinning in opposite directions, and being actively driven in opposite directions, in order to cancel out any unwanted gyroscopic precession. The main issue with using gyroscopes is that they can only exert force when they’re being actively driven in their control axis, and so if they reach the end of their physical limit then the device can no longer balance. When I built my BB-8 robots I made them be able to rotate on the spot. This was achieved by using a reaction wheel. This is a large mass that spins in either direction at a varying velocity but can also stay stationary when it isn’t required to exert any force. I’ve seen various other balancing devices on YouTube that use reaction wheels to balance, but I’ve never tried to make one. So, in this video I’m going to do just that, starting with a simple test rig. CAD & Code: https://github.com/XRobots/ReactionWh... You can support me on Patreon or buy my Merchandise: *************************** Patreon:   / xrobots   *************************** Affiliate links - I will get some money of you use them to sign up or buy something: *************************** Matterhackers 3D printing supplies: http://www.matterhackers.com?aff=7500 Music for your YouTube videos: http://share.epidemicsound.com/xrobots *************************** Other socials: *************************** Instagram:   / xrobotsuk   Facebook:   / xrobotsuk   Twitter:   / xrobotsuk   *************************** CAD and Code for my projects: https://github.com/XRobots Huge thanks to my Patrons, without whom my standard of living would drastically decline. Like, inside out-Farm Foods bag decline. Plus a very special shoutout to Lulzbot, Inc who keep me in LulzBot 3D printers and support me via Patreon. HARDWARE/SOFTWARE Below you can also find a lot of the typical tools, equipment and supplies used in my projects: Filament from: https://www.3dfuel.com/ Lulzbot 3D Printers: http://bit.ly/2Sj6nil Bearings from: https://simplybearings.co.uk/ Lincoln Electric Welder: https://bit.ly/2Rqhqos CNC Router: https://bit.ly/2QdsNjt Ryobi Tools: http://bit.ly/2RhArcD Axminster Micro Lathe: http://bit.ly/2Sj6eeN 3D Printer Filament: http://bit.ly/2PdcdUu Soldering Iron: http://bit.ly/2DrNWDR Vectric CNC Software: http://bit.ly/2zxpZqv Why not join my community, who are mostly made up of actual geniuses. There’s a Facebook group and everything:   / 287089964833488   XROBOTS Former toy designer, current YouTube maker and general robotics, electrical and mechanical engineer, I’m a fan of doing it yourself and innovation by trial and error. My channel is where I share some of my useful and not-so-useful inventions, designs and maker advice. Iron Man is my go-to cosplay, and 3D printing can solve most issues - broken bolts, missing parts, world hunger, you name it. XRobots is the community around my content where you can get in touch, share tips and advice, and more build FAQs, schematics and designs are also available.