{"id":2014,"date":"2020-01-21T11:53:08","date_gmt":"2020-01-21T11:53:08","guid":{"rendered":"https:\/\/www.dronesvilla.com\/?p=2014"},"modified":"2021-12-08T16:00:17","modified_gmt":"2021-12-08T16:00:17","slug":"brushless-motors","status":"publish","type":"post","link":"https:\/\/www.dronesvilla.com\/brushless-motors\/","title":{"rendered":"What Are Brushless Motors?"},"content":{"rendered":"\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full\"><img decoding=\"async\" loading=\"lazy\" width=\"800\" height=\"450\" src=\"https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2021\/12\/drone-brushless-motor-800x450-1.jpg\" alt=\"\" class=\"wp-image-3051\" srcset=\"https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2021\/12\/drone-brushless-motor-800x450-1.jpg 800w, https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2021\/12\/drone-brushless-motor-800x450-1-300x169.jpg 300w, https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2021\/12\/drone-brushless-motor-800x450-1-768x432.jpg 768w, https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2021\/12\/drone-brushless-motor-800x450-1-552x311.jpg 552w, https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2021\/12\/drone-brushless-motor-800x450-1-168x95.jpg 168w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure><\/div>\n\n\n\n<p>Brushless motors are one of many electrical staples that are found in higher-level drones.<\/p>\n\n\n\n<p>But what are they? How do they work? And why are they so important to these devices that have taken over our skies?<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>What Are Brushless\nMotors?<\/strong><\/h2>\n\n\n\n<p>Brushless motors are motors that are powered by direct current through a switching power supply or inverter which transforms the direct current input into alternating current (AC) in order to power the workings of the motor.<\/p>\n\n\n\n<p>The inverter powers each phase of the motor through a closed loop controller. <\/p>\n\n\n\n<p>The controller supplies pulses of current to the motor windings that control the torque and the speed of the brushless motor.<\/p>\n\n\n\n<p>Brushless motors were invented much later than brushed\nmotors (invented in the 19<sup>th<\/sup> century), and they operate differently.<\/p>\n\n\n\n<p>The main advantages that brushless motors have over brushed\nmotors include a higher power-to-weight ratio, higher speed generation,\nelectronic control, and lower maintenance costs.<\/p>\n\n\n\n<p>These advantages have made brushless motors the device of choice for many electronic applications like computer accessories like disk drives and printers, hand held power tools, automobiles, and also aircrafts like drones.<\/p>\n\n\n\n\n<div class=\"aawp\">\n\n            \n            \n<div class=\"aawp-product aawp-product--horizontal\"  data-aawp-product-asin=\"B07ZJZMFFH\" data-aawp-product-id=\"4470\" data-aawp-tracking-id=\"dronesvilla20-20\" data-aawp-product-title=\"DJI Mavic Mini CP.MA.00000120.01\" data-aawp-geotargeting=\"true\">\n\n    \n    <div class=\"aawp-product__thumb\">\n        <a class=\"aawp-product__image-link\" href=\"https:\/\/www.amazon.com\/dp\/B07ZJZMFFH?tag=dronesvilla20-20&amp;linkCode=ogi&amp;th=1&amp;psc=1\" title=\"DJI Mavic Mini Drone\" rel=\"nofollow noopener sponsored\" target=\"_blank\">\n            <img class=\"aawp-product__image\" src=\"https:\/\/m.media-amazon.com\/images\/I\/31iPTd2nOyL._SL160_.jpg\" alt=\"DJI Mavic Mini Drone\"  \/>\n        <\/a>\n\n            <\/div>\n\n    <div class=\"aawp-product__content\">\n        <a class=\"aawp-product__title\" href=\"https:\/\/www.amazon.com\/dp\/B07ZJZMFFH?tag=dronesvilla20-20&amp;linkCode=ogi&amp;th=1&amp;psc=1\" title=\"DJI Mavic Mini Drone\" rel=\"nofollow noopener sponsored\" target=\"_blank\">\n            DJI Mavic Mini Drone        <\/a>\n        <div class=\"aawp-product__description\">\n            <ul><li>12MP \/ 2. 7K Quad HD 3-Axis Gimbal Camera<\/li><li>Up to 30 Minutes of Flight Time<\/li><li>Stream HD Video from up to 2. 5 Miles<\/li><\/ul>        <\/div>\n    <\/div>\n\n    <div class=\"aawp-product__footer\">\n\n        <div class=\"aawp-product__pricing\">\n            \n                            <span class=\"aawp-product__price aawp-product__price--current\">&#36;301.39<\/span>\n            \n                    <\/div>\n\n                <a class=\"aawp-button aawp-button--buy aawp-button aawp-button--amazon rounded\" href=\"https:\/\/www.amazon.com\/dp\/B07ZJZMFFH?tag=dronesvilla20-20&#038;linkCode=ogi&#038;th=1&#038;psc=1\" title=\"Buy on Amazon\" target=\"_blank\" rel=\"nofollow noopener sponsored\">Buy on Amazon<\/a>\n            <\/div>\n\n<\/div>\n\n    \n<\/div>\n\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Why Brushless Motors\nAre Used in Drones<\/strong><\/h2>\n\n\n\n<p>Brushless motors are the device of choice for the\noverwhelming majority of consumer drones available today.<\/p>\n\n\n\n<p>The reason for this is that brushless motors provide a\nbetter thrust-to-weight ratio than brushed motors. And for aircrafts that makes\nall the difference.<\/p>\n\n\n\n<p>In order to fly and be aerodynamic enough to navigate the\nskies, an aircraft has to be as light as possible while being able to generate\nthe power it needs to fly against gravity towards the direction that is\nrequired.<\/p>\n\n\n\n<p>In drones, the propellers are connected to the motors which\nare responsible for making them spin. The propellers themselves spin in order\nto provide the necessary thrust or force needed to take your drone into the\nskies.<\/p>\n\n\n\n<p>There are a bucket load of other technical factors that come\ninto play to provide the flying experience that one expects from drones. But it\nall starts from the motor and its interactions with the propellers.<\/p>\n\n\n\n<p>Within the brushless motors are several electromagnets\n(coils) that are linked in particular pairs.<\/p>\n\n\n\n<p>The motor controller \u2014 popularly called the electronic speed controller \u2014 controls the activity of the motor by activating and deactivating specific sections of the electromagnets found in the brushless motor.<\/p>\n\n\n\n<p>This repeated activation and deactivation is done at very\nspecific intervals to cause the rotor to spin under the influence of the\nmagnetic force generated.<\/p>\n\n\n\n<p>Because these electromagnets are connected to three main\nsections, brushless motors always come with three wires sticking out of them.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Components of\nBrushless Motors<\/strong><\/h2>\n\n\n\n<p>There are two main components or parts that make up a\nbrushless motor. These are the stator and the rotor.<\/p>\n\n\n\n<p>The stator is the stationary part of the motor. It does not\nrotate and contains the electromagnets.<\/p>\n\n\n\n<p>The rotor is the part that rotates and contains magnets\nplaced in a radial pattern.<\/p>\n\n\n\n<p>There are other parts of the motor that are found around\nthese two structures, like coils, shafts, magnets, and so on. But the rotor and\nstator are the components of the brushless motor.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>In-runner and Out-runner Motors<\/strong><\/h3>\n\n\n\n<p>Brushless motors come in two categories: in-runner and out-runner\nbrushless motors.<\/p>\n\n\n\n<p>Multirotor drones and fixed wing aircrafts run only on\nout-runner motors; but they are not the only category that exists. In-runner\nmotors are also a thing and are used elsewhere.<\/p>\n\n\n\n<p>The difference between in-runners and out-runners is that\nfor out-runners the rotor lies on the outer area of the motor. In-runners, on\nthe other hand, have their rotating parts on the inside while the outer parts\nremain stationary.<\/p>\n\n\n\n<p>Because they spin faster, you will normally see in-runner\nmotors used in remote controlled cars.<\/p>\n\n\n\n<p>However, out-runner brushless motors produce more torque or twisting\npower, which means that they are ideal for driving larger propellers. This\nmakes them better for aircrafts and multirotor drones.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Dimension of a\nBrushless Motor<\/strong><\/h3>\n\n\n\n<p>The dimension or size of a brushless motor depends on the\nsize of its stator.<\/p>\n\n\n\n<p>When shopping for a motor for your drone, you may come\nacross devices that are sized in four digits like 2207 or 2306.<\/p>\n\n\n\n<p>What these figures mean is that the stator is 22mm in width\nand 07mm in height or 23mm in width and 06mm in height respectively.<\/p>\n\n\n\n<p>The first two digits indicate the diameter or width of the stator \u2014 which is usually approximated to be the diameter of the motor. <\/p>\n\n\n\n<p>The second pair of numbers denotes the height of the stator, which is also taken as the height of the entire motor.<\/p>\n\n\n\n<p>Why is it important to know the dimension of a brushless\nmotor?<\/p>\n\n\n\n<p>The size of the motor is a good indicator of the size of the\ndrone it is meant for.<\/p>\n\n\n\n<p>Larger quadcopter drones, for example, will use motors of\nthe size 2212 which can be considered large. Smaller drones like racing\nmini-quadcopters tend to use brushless motors that are sized 1806 or 2204.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Performance Factors\nfor Brushless Motors<\/strong><\/h2>\n\n\n\n<p>There are few factors that determine how well a brushless\nmotor does its job.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>kv: The Velocity Constant<\/strong><\/h3>\n\n\n\n<p>Kv, or the velocity constant, denotes the speed at which the brushless motor rotates for each volt input it receives.<\/p>\n\n\n\n<p>To illustrate, imagine a motor that is designated 2300kv\nthat is connected with a 3S drone battery.<\/p>\n\n\n\n<p>This motor will spin at a rate of (2600 x 12.60) rpm \u2014 32,760 revolutions per minute. This rpm is recorded when the motor is not connected to propellers.<\/p>\n\n\n\n<p>When propellers are connected, the rpm reduces slowly due to\nthe effect of air resistance.<\/p>\n\n\n\n<p>Higher kv values usually mean lower resistance, lower\nefficiencies, and higher current draw.<\/p>\n\n\n\n<p>Lower kv values mean higher resistance, lower current draws,\nand better efficiency.<\/p>\n\n\n\n<p>But don\u2019t let the phrases \u201cbetter efficiency\u201d and \u201clower\nefficiency\u201d fool you.<\/p>\n\n\n\n<p>When choosing a motor for your drone, the ideal rpm for you\ndepends on the type of drone you have or are looking for.<\/p>\n\n\n\n<p>For example, if you have eyes for a high performance,\nacrobatic-type drone, you will do well to go for a motor with a high kv value.<\/p>\n\n\n\n<p>This makes sense, because drones like these are the smaller\nvarieties that use smaller motors and, thus, smaller propellers.<\/p>\n\n\n\n<p>Smaller propellers produce less thrust, so the motors have\nto work harder to produce the necessary revolutions per minute to lift the\ndrone.<\/p>\n\n\n\n<p>This need for higher rpm means that these motors use up more\npower and thus are less efficient. However, they get the job done.<\/p>\n\n\n\n<p>On the other hand, if the drone you desire is one which\nneeds to use the least amount of power as possible, in order to last longer in\nthe air and be more stable, you would want to go for motors with lower rpm.<\/p>\n\n\n\n<p>For example, if you desire or own a drone you intend to use\nfor aerial photography, then this would be a larger drone that is capable of\ncarrying a camera payload.<\/p>\n\n\n\n<p>They require larger propellers for greater thrust during\nrotation. They usually require fewer revs per minute in order to fly.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Torque<\/strong><\/h3>\n\n\n\n<p>Torque is simply defined as the spinning force that rotates\nthe propellers. The torque of a brushless motor is affected by factors like:<\/p>\n\n\n\n<ul><li>Stator size: The bigger the stator is, the\ngreater the torque produced.<\/li><li>Quality of materials like the quality of the\ncopper windings in the rotor and the quality of the magnets.<\/li><li>Construction constraints like the presence of\nair gaps between the rotor and the stator<\/li><\/ul>\n\n\n\n<p>The performance of your drone relies heavily on the torque\nproduced by the motor underneath. The torque also affects how responsive a\ndrone is to commands from the pilot. The higher the torque, the more responsive\nthe drone will be.<\/p>\n\n\n\n<p>This relation between responsiveness and torque is important\nfor some pilots like drone racing pilots. <\/p>\n\n\n\n<p>For example, torque will influence how quickly a drone\nresponds to a change in direction in mid-flight around a tight racecourse.<\/p>\n\n\n\n<p>Also, there is the fact that if your drone motor produces\nless torque and comes with heavier props, it won\u2019t spin the propeller as\nefficiently and this will affect thrust. Current draw will also be very high.<\/p>\n\n\n\n<p>On the other hand, motors with high torques have a down side\nin that they feel more snappy and lead to more control errors or oscillations.\nThis is not hard to imagine, given that drones with high torque motors can\nchange their rpm much faster and may over respond to input, making them harder\nto control.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Efficiency<\/strong><\/h3>\n\n\n\n<p>To get the efficiency of a brushless motor, you divide the\nthrust force produced by the motor while at 100% by the power produced by the\nmotor.<\/p>\n\n\n\n<p>The unit of measurement for efficiency is grams per watt (g\/w).<\/p>\n\n\n\n<p>The higher this ratio is, the more efficient the motor is,\nbasically. So you want to pay attention to this is aspect of the motor when\nmaking a choice.<\/p>\n\n\n\n<p>Keep in mind that you will not be flying your UAV at full\nspeed all the time, so it is important to consider the efficiency of the\nbrushless motor at various speed ranges from between 0% and 100%.<\/p>\n\n\n\n<p>Some motors may be more efficient at one end of the speed\nspectrum than at the other. Some engines shine when speeds are low, while\nothers come into their own when the devices is flown at high speed.<\/p>\n\n\n\n<p>You want to, therefore, choose a motor that produces the\nhighest efficiency for your style of flying.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Current Draw<\/strong><\/h3>\n\n\n\n<p>The current draw of a brushless motor is important in\ndetermining the size of the electronic speed controllers required for that\nmotor.<\/p>\n\n\n\n<p>For example, a motor of size 1104 draws a maximum of 10A at\n100% throttle, while some motors of size 2306 draw a maximum of 40A at 100%\nthrottle.<\/p>\n\n\n\n<p>Electronic speed controllers have to be selected in such a\nway that they are rated 20% more than the current drawn by the motor at 100%\nthrottle.<\/p>\n\n\n\n<p>So, if a motor draws 30A max at 100% throttle, it would\nrequire an electronic speed controller rated at 36A constant current.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Temperature<\/strong><\/h3>\n\n\n\n<p>Temperature or heat is bad for motors over time. When exposed\nto heat for a long time, the magnets in the rotors tend to lose their strength\nprogressively.<\/p>\n\n\n\n<p>Eventually they become demagnetized due to the constant heat\nand this in turn results in a shortened lifespan of the motor.<\/p>\n\n\n\n<p>There are a few reasons why a brushless motor might overheat,\nincluding 0ver propping and constant speeding over long periods of time.<\/p>\n\n\n\n<p>For drone racers, flying at high speeds is expected. But if\nyou are not a racer and you find your drone overheating, it is likely that your\nmotor is over propped.<\/p>\n\n\n\n<p>Motor manufacturers and drone manufacturers make up for this\npotential problem by installing cooling fins to help direct air into the motor\nto cool it and prolong its lifespan.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Brushed vs. Brushless\nMotors<\/strong><\/h2>\n\n\n\n<p>When it comes to brushed motors and brushless motors in\ndrones, there are a few differences in the way they are constructed and the\nadvantages each possess.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Differences in\nConstruction<\/strong><\/h3>\n\n\n\n<p>A brushed motor is made with a rotating stator which acts as\na two-poled electromagnet. The shell does not move, thus brushed motors can\neasily be mounted without the help of screws.<\/p>\n\n\n\n<p>On the other hand, brushless motors use a permanent magnet\nand generate power by way of an inverter. There is no need for brushes, hence\nthe name \u201cbrushless\u201d. Because the motor bell moves, brushless motors require screws\nin order to be mounted.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Advantages of Brushed\nMotors<\/strong><\/h3>\n\n\n\n<ul><li>They are not expensive to manufacture<\/li><li>Can be made in the small sizes<\/li><li>Useful in extreme environments lacking in electronics<\/li><li>Replaceable brushes make for prolonged lifespan<\/li><li>Two wire control is simple<\/li><li>They do not require a speed controller since speed is fixed<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Advantages of\nBrushless Motors <\/strong><\/h3>\n\n\n\n<ul><li>No brushes make for lower maintenance costs and\nlonger durability<\/li><li>Better speed and higher torque due to the lack\nof brushes and the friction they produce as speeds increase<\/li><li>Wider speed range<\/li><li>Mode of construction make them better at dissipating\nheat than their brushed motors<\/li><li>More cost effective for high speed and high\npower operations<\/li><\/ul>\n\n\n\n<p>The advantages of brushed motors make them ideal for power\ntools, fan motors, computer peripherals, and small-sized motorized toys.<\/p>\n\n\n\n<p>On the other hand, the advantages of brushless motors make them ideal for radio-controlled aircrafts like drones, electric cars, and also industrial machinery \u2014 stuff that require high rotation speed and power.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Brushless motors are one of many electrical staples that are found in higher-level drones. But &#8230; <a title=\"What Are Brushless Motors?\" class=\"read-more\" href=\"https:\/\/www.dronesvilla.com\/brushless-motors\/\" aria-label=\"More on What Are Brushless Motors?\">Read more<\/a><\/p>\n","protected":false},"author":3,"featured_media":2149,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","footnotes":""},"categories":[16],"tags":[],"uagb_featured_image_src":{"full":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors.jpg",825,457,false],"thumbnail":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors-150x150.jpg",150,150,true],"medium":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors-300x166.jpg",300,166,true],"medium_large":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors-768x425.jpg",768,425,true],"large":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors.jpg",825,457,false],"img_rate_products_categories":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors-552x306.jpg",552,306,true],"img_rate_products_slideshow":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors.jpg",825,457,false],"img_rate_products_preview":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors-168x93.jpg",168,93,true],"1536x1536":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors.jpg",825,457,false],"2048x2048":["https:\/\/www.dronesvilla.com\/wp-content\/uploads\/2020\/01\/brushless-motors.jpg",825,457,false]},"uagb_author_info":{"display_name":"Sam","author_link":"https:\/\/www.dronesvilla.com\/author\/sam\/"},"uagb_comment_info":0,"uagb_excerpt":"Brushless motors are one of many electrical staples that are found in higher-level drones. But ... Read more","_links":{"self":[{"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/posts\/2014"}],"collection":[{"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/comments?post=2014"}],"version-history":[{"count":1,"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/posts\/2014\/revisions"}],"predecessor-version":[{"id":3052,"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/posts\/2014\/revisions\/3052"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/media\/2149"}],"wp:attachment":[{"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/media?parent=2014"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/categories?post=2014"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.dronesvilla.com\/wp-json\/wp\/v2\/tags?post=2014"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}