Have you ever wondered what the best motor is for your Micro FPV Race drone?
There's so many options out there how do you go about choosing the right one? Well,
today we're gonna show you a method that's gonna help you choose just the
right motor for your micro and we're gonna give you a cheat sheet in the form
of our 1st edition Micro FPV motor chart that's gonna make it easier. Let's
do this! So, what is the best motor for your Whoop, 2, 2 1/2, or 3 inch
quad? That's gonna be determined based on how you define the term "best."
Does that mean the highest top-end speed, or the most responsive motor? What about
the longest flight time? Is that what you're concerned about? Because that
will mean that you want the most efficient motor. There will be trade-offs
that need to be made. Factors to consider in those trade-offs
are the max prop size that you'll be using, the number of cells in the battery
that you're going to be using, what's the physical size of your motor gonna be,
what's its kV or velocity constant, how fast is the motor gonna be spinning, what
type of thrust you actually need for the type of flying that you'll be doing.
What's the motor weight because together the thrust and weight will
determine your motors thrust to weight ratio which to me is actually one of the
most, if not the most, important factor. Keep in mind there are four motors on
your quad-they're the heaviest quad component so if you've got motors with
the same (with similar or almost the same) specifications then you're probably
going to want to choose the lightest motor for your quad. If you're concerned
about flight time and you want to extend your flight time then you probably want
the most efficient motor and efficiency is determined based on your thrust to
the power that the motor is consuming. That's your thrust to power ratio which
depends on the props size and type that you'll be using as well as the number of
cells in your battery actually and also the percent throttle that you normally
fly at. Torque is another thing to keep in mind. Higher torque motors
are generally more responsive and have a sharper response than lower torque
motors which feel smoother. Will you be doing freestyle or racing? Higher torque
motors may be more conducive to racing whereas lower torque motors with a
smoother flight profile might be more conducive to freestyle. You'll also want
to determine what the current draw of your motors is because that's going to
determine the size of the ESC you'll need for your build. For instance, if you
have an 18.6 amp current draw for your motor than you probably want to
get an ESC rated for about 20 amps. One of the things that you always want to
keep in mind is what is the mounting pattern of your motor? Because that's
going to determine whether or not it's actually going to fit on your frame! For
example is it a 9x9 or 12x12 mounting pattern? Some frames
actually are able to accommodate several types of mounting patterns. Also, keep in
mind whether or not the motor is durable and can withstand some "unintended
landings", and obviously, the cost of the motor because you're going to be
multiplying it by 4. With respect to how fast the motor is spinning or the
motors rpms, that's defined by the velocity constant or the kV rating of
your motor times the voltage of your battery. For our calculation purposes,
we're gonna assume one cell is going to be 4.2 volts so a two cell battery times
4.2 volts that's gonna be 8.4 volts, three cell is gonna be 12.6
and 4S is going to be 16.8. Therefore, for a 2S
battery and a 3750 kV motor your rpm is going to be 31500
for a 3S similar calculation it's going to be 47,250 rpms
and for a 4S at that kV rating it's going to be 63000 rpm.
keep in mind your higher kV motors you'll be wanting to use a lower cell
battery count to avoid motor or ESC burnout you don't want to smoke your
motors the torque of your motor is going to be somewhat dependent upon its motor
size the eyes of Motors is generally depicted by
four numbers the first two numbers are going to be your state or diameter how
wide is it the last two numbers are going to be the state or height
generally wider motors have lower top-end speed but better handling ie
more torque at those lower speeds taller motors have a higher top-end speed but
less handling capability ie less torque at those lower speeds so generally
larger skaters or larger motors are capable of more torque more responsive
sharper field we've developed a simple five-step methodology to help folks
choose the best motor for their micro ftv build the first step is to determine
what the maximum prophesize is for the frame that you'll be using then
determine what size battery you'll most likely be using the number of cells what
type of flying will you be doing are you going to be racing are you going to be
doing freestyle are you an aggressive flyer will you be doing some slow smooth
cruising around those types of things we'll help you decide what type of motor
that you'll be needing for your build once you're able to step through these
three steps then you can compare the specifications of the remaining motor
choices that you have by looking at a chart similar to this one once you've
determined your prop size and the number of cells of your lipo battery then
you've limited yourself to a specific motor size range which will relate to
the kV rating range of the motors which will also tell you how fast your motors
will be spinning remember to match the number of lipo cells with your motor kV
rating and the correct prop and size of a prop to avoid smoking your motors you
don't want to over prop your motors here's a specific example of what I'm
talking about for two-inch prop size using a two cell battery
we're looking at motor sizes around at 11:06 in this case with an 8000 kV
rating that's going to give us an RPM of 60 7200 for this particular motor that
we're considering its thrust at 100% throttle is 230 the motors weight is 8
grams which gives us a motor thrust to weight ratio of 20 8.75 now if I've got
this motor and another 1106 motor from another brand I can compare their thrust
to weight ratios and what I will choose is the one with a higher thrust to
weight ratio now what we've done to help folks out is we've actually filled out
the data and created our first addition micro fpv motor chart which you can
download from the link in the video description below we say first edition
dated March 22nd 2019 because we will be updating this chart at least on a
monthly basis so at any time you can go back to that link in the video
description below and pull up the chart and get the latest version of the chart
the chart includes 33 different motors with a prop range from 40 millimeters to
3 inches and it includes 13 different manufacturers such as happy model diet
own beta fpv air blade get barsy spin tech t motor brother hobby
now if you'll see your favorite brand motor up here and/or the chart does not
include your favorite specific motor and you want it included then go ahead and
put it in the comment section below and we'll make sure and included in the
chart in the next revision now once you've narrowed down your choices to one
or two motors the next step is to search the reviews on those particular motors
to see if there's any durability or other issues that you need to be made
aware of before making that purchase remember to match your motor max current
draw with your ESC you don't want to smoke your motors again we're confident
that when you follow this five-step methodology using the micro
PB motor chart that you will find the best motor for your micro boss rocket
thanks for watching we appreciate your time we'll see in the next video and
happy flying