Editing Gyroscope (section)

===Commercialization===
In the 1860s, the advent of electric motors made it possible for a gyroscope to spin indefinitely; this led to the first prototype [[heading indicator]]s, and a rather more complicated device, the [[gyrocompass]]. The first functional gyrocompass was patented in 1904 by German inventor [[Hermann Anschütz-Kaempfe]].<ref>Hermann Anschütz-Kaempfe and Friedrich von Schirach, [http://v3.espacenet.com/publicationDetails/originalDocument?CC=DE&NR=182855C&KC=C&FT=D&date=&DB=&locale= "Kreiselapparat"]{{Dead link|date=September 2024 |bot=InternetArchiveBot |fix-attempted=yes }} (Gyroscope) Deutsches Reichspatent no. 182855 (filed: 27 March 1904; issued: 2 April 1907).</ref> American [[Elmer Sperry]] followed with his own design later that year, and other nations soon realized the military importance of the invention—in an age in which naval prowess was the most significant measure of military power—and created their own gyroscope industries. The [[Sperry Gyroscope Company]] quickly expanded to provide aircraft and naval stabilizers as well, and other gyroscope developers followed suit.<ref>MacKenzie, Donald. ''Inventing Accuracy: A Historical Sociology of Nuclear Missile Guidance''. Cambridge: MIT Press, 1990. pp. 31–40. {{ISBN|0-262-13258-3}}</ref>{{full citation needed|date=July 2022}}

Circa 1911 the L. T. Hurst Mfg Co of Indianapolis started producing the "Hurst gyroscope" a toy gyroscope with a pull string and pedestal. Manufacture was at some point switched to Chandler Mfg Co (still branded Hurst). The product was later renamed to a "Chandler gyroscope", presumably because Chandler Mfg Co. took over rights to the gyroscope. Chandler continued to produce the toy until the company was purchased by TEDCO Inc. in 1982. The gyroscope is still produced by TEDCO today.<ref>{{cite web|url=http://blog.makezine.com/archive/2009/02/tedco_toys_cool_company_history_gre.html |title=TEDCO Toys – Cool company history, great science kits |last=Anon |work=TEDCO Toys company website |publisher=O'Reilly Media Inc |access-date=23 December 2010 |url-status=dead |archive-url=https://web.archive.org/web/20090309071225/https://blog.makezine.com/archive/2009/02/tedco_toys_cool_company_history_gre.html |archive-date=9 March 2009 }}</ref><ref>{{cite web|url=https://www.gyroscope.com/history-of-the-tedco-gyroscope.asp |title=History of the Tedco Gyroscope |publisher=Brightfusion Ltd |access-date=10 May 2024}}</ref>

In the first several decades of the 20th century, other inventors attempted (unsuccessfully) to use gyroscopes as the basis for early [[flight recorder|black box]] navigational systems by creating a stable platform from which accurate acceleration measurements could be performed (in order to bypass the need for star sightings to calculate position). Similar principles were later employed in the development of [[inertial navigation system]]s for [[ballistic missile]]s.<ref>MacKenzie, Donald. ''Inventing Accuracy: A Historical Sociology of Nuclear Missile Guidance''. Cambridge: MIT Press, 1990. pp. 40–42. {{ISBN|0-262-13258-3}}</ref>{{full citation needed|date=July 2022}}

During World War II, the gyroscope became the prime component for aircraft and anti-aircraft gun sights.<ref>[http://www.popsci.com/archive-viewer?id=PiEDAAAAMBAJ&pg=86&query=destroyer+escort The Little Top That Aims a Gun] {{webarchive|url=https://web.archive.org/web/20110710151152/http://www.popsci.com/archive-viewer?id=PiEDAAAAMBAJ&pg=86&query=destroyer+escort |date=10 July 2011 }} by Gold Sanders, ''[[Popular Science]]'', July 1945</ref> After the war, the race to miniaturize gyroscopes for guided missiles and weapons navigation systems resulted in the development and manufacturing of so-called '''midget gyroscopes''' that weighed less than {{convert|3|oz|g}} and had a diameter of approximately {{convert|1|in|cm}}. Some of these miniaturized gyroscopes could reach a speed of 24,000 revolutions per minute in less than 10 seconds.<ref>{{cite web|url=https://books.google.com/books?id=nNwDAAAAMBAJ&pg=PA148|title=Popular Mechanics|first=Hearst|last=Magazines|date=1 March 1954|publisher=Hearst Magazines|url-status=live|archive-url=https://web.archive.org/web/20170202032244/https://books.google.com/books?id=nNwDAAAAMBAJ&pg=PA148|archive-date=2 February 2017}}</ref>

Gyroscopes continue to be an engineering challenge. For example, the axle bearings have to be extremely accurate. A small amount of friction is deliberately introduced to the bearings, since otherwise an accuracy of better than <math>10^{-7}</math> of an inch (2.5&nbsp;nm) would be required.{{sfn|Feynman|Gottlieb|Leighton|2013|pp=148–149}}

Three-axis MEMS-based gyroscopes are also used in portable electronic devices such as [[tablet (computer)|tablet]]s,<ref>{{cite web|url=https://www.apple.com/ipad/compare/|title=iPad – Compare Models|website=Apple|url-status=live|archive-url=https://web.archive.org/web/20121024015359/http://www.apple.com/ipad/compare/|archive-date=24 October 2012}}</ref> [[smartphone]]s,<ref>{{cite web|url=http://www.ifixit.com/Teardown/iPhone-4-Gyroscope-Teardown/3156/1|title=iPhone 4 Gyroscope Teardown|date=24 June 2010|url-status=dead|archive-url=https://web.archive.org/web/20111124144402/http://www.ifixit.com/Teardown/iPhone-4-Gyroscope-Teardown/3156/1|archive-date=24 November 2011|access-date=11 November 2011}}</ref> and [[smartwatch]]es.<ref>{{cite news|url=https://www.bbc.com/news/technology-29107354|title=Smartwatches: Specs and reviews for the leading models|date=9 September 2014|last=Kelon|first=Leo|newspaper=[[BBC News]]|department=Technology|url-status=live|archive-url=https://web.archive.org/web/20150828140736/http://www.bbc.com/news/technology-29107354|archive-date=28 August 2015}}</ref> This adds to the 3-axis acceleration sensing ability available on previous generations of devices. Together these sensors provide 6 component motion sensing; accelerometers for X, Y, and Z movement, and gyroscopes for measuring the extent and rate of rotation in space (roll, pitch and yaw). Some devices<ref>{{Cite web|date=24 June 2018|title=Best Android phones with Gyroscope and Accelerator|url=https://aptgadget.com/android-phones-gyroscope-accelerator/|access-date=9 December 2020|website=AptGadget.com|language=en-US|archive-date=26 November 2020|archive-url=https://web.archive.org/web/20201126172745/https://aptgadget.com/android-phones-gyroscope-accelerator/|url-status=live}}</ref><ref>{{cite web|url=https://www.safaribooksonline.com/library/view/basic-sensors-in/9781449309480/ch05.html|title=Basic Sensors in iOS|url-status=dead|archive-url=https://web.archive.org/web/20150723214608/https://www.safaribooksonline.com/library/view/basic-sensors-in/9781449309480/ch05.html|archive-date=23 July 2015|access-date=23 July 2015}}</ref> additionally incorporate a [[magnetometer]] to provide absolute angular measurements relative to the Earth's magnetic field. Newer [[Vibrating structure gyroscope#MEMS gyroscopes|MEMS-based inertial measurement units]] incorporate up to all nine axes of sensing in a single integrated circuit package, providing inexpensive and widely available motion sensing.<ref>{{cite web |url=http://www.st.com/web/en/catalog/sense_power/FM89/SC1448/PF258556 |title=LSM9DS0 iNEMO inertial module:3D accelerometer, 3D gyroscope, 3D magnetometer - STMicroelectronics |access-date=23 July 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150723233203/http://www.st.com/web/en/catalog/sense_power/FM89/SC1448/PF258556 |archive-date=23 July 2015}}</ref>