How To Build a Remote Controlled Lawn Mower


Hey guys! It’s “Mr. Meant To Be Lindsey B”
here and today I wanted to show you how I turn this lawn mower into the remote
control powered lawn mower that I showed you in the previous video. I’ve had a lot
of people asking me “How you do it?” “How easy is it?” How expensive is it?” “What did
you do?” “What did you not do?” – So today, I want to just kind of go through how I
did it. I put it back into a regular lawn mower figuration. I’m going to take all
the parts off and put the power parts back on, so this isn’t a step-by-step
exactly how I did every bolt… but I will talk you through the procedure that I
did… the decisions that I made… and what I did and why…. and let’s get started. So, the first thing
I did was I had to take off handle. So, the handle’s really easy. There’s just a
couple of bolts on these fins on here to hold it on. I’m just gonna take those
bolts off and then I need to remove the cables here. The cables go to the auto
kill… and then on the other side, there’s a throttle and they’re just these cables
and they’re kind of go in these little fins right here. You just remove them and
should come right off. So first, we’ll remove this cable right
here. This has these tabs you push in. Pull this out. It comes off… comes off
of there and then this is like a bendy piece. Bend it around. Pull it off… and I
also removed the very heavy spring that’s here. We’re gonna replace this
with a much lighter spring that we can actually actuate this with our fingers
and it still work like supposed to… and the bolts work just like you expect
bolts to work. Pull the bolt out and when you get them all, this will just kind of
fall out. Okay. So, this is the space we have to mount all the hardware that
we’re gonna need. I’m going to take the wheels off, mount the motors to these
really convenient fins we have here and then I’m going to put the batteries and
the motor driver and any other electronics that I need right
here in the middle. So first, I want to find out what kind of space were working
with right here. So, I’m gonna put the batteries in place and just kind of see kind
of the layout of how things are gonna look. Okay. So here are the batteries I’m
working with. I’m doing two 12-volt 22 amp power batteries. They cost around I
want to say $40-$50 a piece. So, I’m gonna use two of them… and
another big decision that I get to make while doing this is… Do I want to run it
as 12 volts or do I want to run it as 24 volts? With 12 volts, you can get twice
the the operating time with two batteries… but with 24 volts you can make
it go much faster and get a lot more power
right off the hop. So, a lot of the components that I’m using work as 12
volts or 24 volts. So later on, we can kind of mix and match and see which one
works best for our use case. I will tell you in the previous video, I went with 12
volts because 24 volts just seemed too fast but we can actually wire it up like
that and see see how it performs… but first… Let’s figure out how much
space we have right here for our components… and it looks like with both of
those batteries in place, we have a little under nine inches to work with…
which is a ton of space… and this way looks like about six… and I decided to go
with mounting my components to a piece of wood right here rather than directly
to the mower because 24 volts mounted directly to a metal chassis just
doesn’t sound like… this doesn’t sound like a really good plan. So, I’m gonna
mount it to a piece of wood. That way, I can move stuff around, screw it down
securely and have a little bit of insulation so stuff doesn’t get shorted
out quite as easily. So, let me go cut a board that’ll fit exactly in that space…
and here we go… piece of wood that will fit exactly between these two
batteries and will also kind of give them a little more stabilization in
their place too… and now I have plenty of room to put my drivers, my fuses… any
other electronics that I might that I may need for this build. Okay guys… So,
what I have here are the basic components of what you need to make a
remote-control lawnmower. It’s not a lot but each piece performs a very vital
function that you have to have to make something like this part. First thing
you’re going to need is the motors. These are motors from a Permobil M300
chair, I believe. They run at 24 volts but they all can also run at 12 volts, which
is something that I like a lot. They are reversible. They’re very heavy.
I think they’re about 12 pounds apiece with the motor, the gearbox and the wheel
mount here… and over here are the wheels that go on it. They are also about 10
pounds and they are removable with just a couple of bolts, which makes it very
convenient for our use. Each motor has a positive and negative
power wire going into it and that’s how it drives forwards and backwards. Super
easy to use and those are fed by what’s called a motor driver. This is kind of
the brain box of the whole operation. It takes power from the batteries in these
middle two terminals. You hook the right motor on the right side… the left motor
on the left side and then it interprets signals from the receiver here to power
which… which motor at which time in which direction that you choose. So, this is the
most important part. You want to get one that’s rated for the amount of power
you’re going to be using and that depends heavily on the voltage that you’re
using and the motors that you’re using. So, you’ll want to… you want to make sure
you have a large enough motor driver to power your motors to control the motor
driver. I have a remote receiver here and what this does is it… This is powered
from the motor driver itself. It actually… The motor driver puts out a five volt signal
power to power this module. Plug that in there and then I have a channel
1 and channel 2 signal. That’s gonna be a signal for moving forward and moving
side to side. So, it’ll interpret those signals to make both motors go forward
or reverse or one to go forward and one to go in reverse… to make it turn left
and one to go or the opposite to make it go the other direction. So, that’s how it
kind of controls the whole thing. So, all you have to do is take channel 1 and
channel 2 from your receiver and put them into the signal 1 and signal 2 of
the motor driver here and then the receiver receives the signal from the
transmitter. So, the way this is set up is that channel 1 is forward and reverse on
this stick and channel 2 is left and right on this stick and those signals are
interpreted by the motor driver to put the appropriate power to them to the
motors. A couple of safety precautions… I have is a physical switch… I put a
physical switch in the line, so I can power this off just with a flick of a
switch and it’ll turn this… break the circuit from the batteries to the motor
driver… turn everything off. That’s a very
important thing. Another thing I did is I’m… I’m installing a 60 amp fuse on the
positive lead of the battery to the motor driver, so that if there’s a short
it will turn itself off. So, what I’m gonna do is turn the motor
driver on like that and there’s a blinking light here to indicate that
this is receiving power, which means the whole thing is receiving power… turn on
my receiver. So, I have the batteries wired up in series so that the motor
driver is receiving 24 volts… which I will show you the full power that the motors
can put out and I’ll show you why that’s just way too much. So that I’ve measured
it’s about 7 miles an hour and it’s just way too fast to be trying to control a
lawnmower driving around the yard. It may be great if you have a very, very large
yard and you can just let it go and you don’t want it to take forever… but at
half the speed, we’re gonna get… get about 3 miles an hour and that’s gonna be a
lot more appropriate for what we’re trying to do. Okay. So now I have everything mounted to
my board. I have the fuse, switch, motor driver… all the wires hooked up and then
also I did this AC or DC to DC converter. This will convert 12 volts or 24 volts
DC down to 5 volts. So I can use it to power servos or anything else electronic
that I want to power. That’s… that’s just off of like USB type power. So this will
help with some lower power electronics. So, I have my receiver hooked up right
here just like it was. So now we can take this and find the way to mount it to the
actual back of the mower where it goes. So what we need to do is remove the wheels
and then remove the height leveling adjustment and the axle here and that’ll
give us free access to the whole back of this mower… and there we have it. So you
can see where I’ve already mounted my motors before. I took a piece of this… of
this metal here and cut it out so that I could put the gearbox right there and
drill the holes to mount it. I’ll show you how I do that in a second… but I just
wanted to show you first… This is the kind of space for working with and these
adjusting brackets right here make it really, really convenient for mounting
motors and stuff. So, this one I’m gonna mount the motors to the lawnmower. My
original idea was to use the bolts that were here… the bolt holes that are here
in the motors to connect… to drill holes in the appropriate places in these… in
these brackets and have it mounted but what I found out after I did that was
that if this was mounted here on this, the wheel that mounted here didn’t have
enough clearance from the actual lawnmower where stuck out. So I had to
pull it out to where it mounted to this big part of the gear housing… and one big part with that is that these screw holes go all
the way through whereas these you would screw it straight in and it would stay
right there. So I had to… So now I have to go all the way through and put a nut on
the other side… which isn’t a deal breaker… but it’s just something I had to
learn the hard way to give myself clearance to do this. You can see I did
some pretty gnarly cuts here. I cut up in here and then I kind of placed it and
then I try to rough out the shape of this circle right here… right here with
just an angle grinder and a hacksaw. I did the best I could. There are much, much
better ways to do it but I was just trying to do it just by hand
by eye… eventually got it to where the rough shape of this circle right here
and then put the screw holes here and here… here and here… so that they line up
and then do the same thing for the other side… and just like that. We’ll do that on
the other side too. Okay. So now with the motors mounted and the board of
electronics where it’s supposed to be. I want to get the batteries back on here…
give it a dry run and see where we’re at. Okay. So last time, I built this I used
only one battery just to get 12 volts. This time, I was gonna use two, put them in
parallel to get twice as much amp… amp-hours out of the same 12 volts but
I’m realizing that this is shaped differently on this side, so that this
battery does not fit with this motor in place. So that’s not going to work.
So, I’m just gonna go back to just using the one battery. 12 volts
was plenty… and it has 22 amp hours, so that’s plenty enough to do just a
small yard that we have and can easily be charged in between or swapped out if
need be. So… we’re not going to do the two batteries. I’m only going to do the one. Okay. So now that we’ve got everything basically wired up… like I
said we have the one battery into a fuse with a switch going into the end of the
motor driver. We have the remote receiver channel one and two plugged into the
motor driver. We have this DC to DC power converter that we’re not using yet but
I’ll show you what we’re gonna do with it later. We have the motors each plugged
into each side of the motor driver and we have the transmitter. We’ll turn on. Then we’ll turn the motor driver on and that beep says that it’s connected. So, if we
go forward, you can see that both motors go forward. If we go reverse, both motors
go reverse. Left means they go opposite directions. The left side will go
backwards. The right side go forward. To turn it like… like this and same thing
for right… and then if you go forward and left… just the just the side will push
forward and forward and right… just that side will push. So, that…that’s how it
drives. So, it’s looking pretty good. So, the next thing we’re gonna work on is the
throttle control for the mower itself. I’m gonna use a servo so that can
throttle up and throttle down the mower based on if it needs to spin faster or spin
slower or if I can turn it off completely. So, I’m going to show you how
I hooked that servo up next. Okay. So, this is the throttle control for the actual
engine that powers the blades. So, the way that works like normally on a push
mower if you… There’s a lever on the handle. If you push it forward it goes
faster. If you pull it back, it goes slower. So all that does is move this
piece right here. This piece moves the governor and the governor tells it how
much or how little fuel to add to tell it how fast it’s going. So all we need to
do is put a servo that manipulates this piece right here just like it does when
you do the handle. So, what I’m gonna do is take the server right here and going
to mount it right right here on this piece. With that mounted there,
I can use the control arm to this piece right here to move this… to move this in
and out. So that’s what I need to do… is mount this servo into these holes that
I’ve already conveniently drilled for myself right here. Okay. So now I have the
servo hooked up to the governor and it’s plugged into the appropriate channel on
my receiver so that on my transmitter, I can… just like that… Okay. The next thing
we’re gonna fix is the shut off. This is the kill switch.
This part is normally handled by the dead man switch on the push handle and
what it does is normally two pieces right here are separated. It breaks the connection
of the electronics for the engine and it dies. When they’re together,
it allows the connection the power to flow to the spark plug and will stay
running. So what we need to do is have it stay running until we don’t want it to
stay running and then we’ll move it. We’ll be able to move it apart to break
the connections. So, I took out that big, heavy spring earlier because it was just…
you couldn’t possibly move it by hand. It was just too… too strong. So, what I’m
gonna do is replace it with this much lighter spring and I got this at Home Depot
just in their spring drawer and it fits perfectly and it’s super light so you
can actually you know trigger this with your finger or my next plan is to get
another servo… maybe a mount it here and have it also servo driven so I can
kill the mower from the remote from a distance but that’s a project for
another day. Another idea I have is maybe doing figuring out the actual
electronics into an electronic relay but I think the servo kill switch idea will
probably,,, probably be better so… So that’s all we do is just put the spring on here and I
can also put a bolt or something in here to make this a little easier to
trigger if this piece is kind of more buried under this plastic or if this
gets really hot and I don’t really want to have
to get my fingers in here, I can put you know extend this and make it easier to
do too, so that’s one thing we had to do. So that should be it for the actual
driving system and running system. Now, the next thing we need to worry about is
the front wheels. These wheels are not going to work at all. These are not going
to allow me to turn the mower by going left and right at all. So what I’m going
to do is replace them with deck wheels. These are nice and plastic and wide and
kind of slick so that these can actually slide side to side to allow the mower to
turn on the grass and on the concrete and whatever. Another solution that I’m
going to go to next is get an actual caster that… that turns just like on a
wheelchair the front… your front casters on your wheelchair turn. I’m going to put
something like that on here, I just haven’t had time to find the mounting
system or build something that will actually support that much weight and be
able to turn, so this will work in place of that for now. I’ll just bolt these on
where these are right now and these will at least allow it to slide side to side
a lot better than these do and for this what I’m going to do I’m going to use
the bracket that the wheel is mounted to but I’m not going to use the axle. So
I need to take this off so I get this axle out and then remount this back on. So I’m
going to mount my wheels to this bracket right here that’ll also give me the
original adjustment height adjustment that that’s provided. Okay. So now without
those pesky bolts in the way, we could take our deck wheels with the nut and just
run it through the hole where the axle was and bolt this on… and the wheels just mount on to the
motors here with just four screws and they just go into the four bolt holes
here and that’ll be it for the drive system. Okay. So like I mentioned in the… in the
demonstration video, the way I start it is with the power drill and two reasons
I do that. One… this motor was free because the… the string that you would
normally pull is broken. It’s just gone… and two… the carburetor needed to be
replaced and it wouldn’t start, which is why they were yanking on the cord ao hard,
which is why they broke it and they were just fed up with it. So he just gave it
away and I was lucky enough to actually be online when they posted it and I live
close enough I could just run and pick it up right then. It was really, really
convenient. So the way we’re gonna start is with a power drill. So we have to do is
remove this cover and then remove the string pull mechanism. I actually had to
drill these rivets out. It had rivets holding in this… I just drilled them out…
pulled it off just like that and if I wanted to put a string back on it I
could but I don’t want to have to do that because pulling on something like
that as a wheelchair user is extremely difficult. So I’m gonna do just like in
the video we would… we would just take our power drill we have a 5/16 socket on
the end and there’s a nut inside this right here. I just put that on that nut
and crank it for a little bit and it will it’ll fire up. I’m not going to do it right
now because I’m not trying to mow the yard. That’s all you have to do. So now I
want to test out the drive system and let’s see how we did. So to test it out,
what we’re gonna do is just flip on the switch that we have. Flip on the receiver
and just drive around a little bit. Alright. That works great. Awesome! So… so
again… I’m just gonna go over everything that’s involved and talk about maybe
what we’re going to do in the future. Okay. So, I’m gonna try to go over all the
parts again. I don’t remember the prices off the top of my head, so I’m gonna kind of ballpark them. The battery I got on Amazon. It’s approximately $50. The fuse
also got an Amazon. It’s probably about $10. The switch I got at Lowe’s fo $3. The motor driver… This is a dual 25 amp motor driver. Should be powerful
enough to power either of the motors at 12 volts or 24 volts and that should be
fine. The motor driver itself I got an Amazon
for about $125. The motors are from a Permobil M300 wheelchair and you can
get them on eBay or some disability trading groups where people are selling
power chair and power chair parts. So we got this DC to DC converter. For now, this can
power the receiver or it can also power servos. It can power any custom
electronics like Raspberry Pi or arduino board. So, I want to add maybe… maybe a
camera system… something like that. This will give me a constant source of power for that. Up
front, I just put a servo to the throttle control and governor and for the kill
switch I just installed this spring that’s a lot easier to do with your
fingers. I may also put a second servo on that. You can get a pack of two pretty powerful
servos on amazon for $20. It’s not really that expensive. With that I had to do a
tune-up which included a new carburetor, a new air filter, new spark
plug and a little bit of luck. got it to fire right up… wasn’t too bad.
Okay guys. So, I think that’s it. This is just a very basic build. I do have a lot
of ideas for the future like I said. I mentioned that I want to maybe add some
camera system. I’d like to be able to have a camera mounted on it so I can mow
the yard from like inside the house just have it on the TV or something. How cool
would that be. I’d also like to put some more safety
features in place like where I could kill the power from the remote from
anywhere at any point. I’d also like to be able to use the kill switch or the
throttle kill at any point in case something goes wrong with with the mower.
I’d also like try to figure out the out of range auto kill feature on the remote
so if it gets out of range it’ll automatically kill the mower, kill the
power… kill everything and let me catch up and come get it. I haven’t had it try
to run away from me yet but I’m not saying it’s not possible. I know radio
interference is a major issue so that’s something I’m definitely gonna do, I am
going to put caster type wheels on the front rather than the sliding one. This works but it doesn’t work great. I’d rather it be able to turn 360 and it
would be a lot more uh… more efficient… a lot less hard on the grass when it’s
doing it. I would like to have two batteries rather than just the one, even
if I’m doing 12 volts. That way, I can have twice… twice the battery life but
for now one is fine as long as I charge it every mow or every other mow. No big deal.
I’m really happy with the way this turned out. I would like… also like in the
future to build one that’s not gas. I would like to go get a a powered one
maybe the Ryobi… the 40 volt one and put the same type of system on that so I
don’t have to worry about carburetor and gas and starting it all the stuff. If I
could just not deal with all that and just turn it on and go, charge it and
maybe even run the motors off at the same battery that the motor
runs off of. That would be really convenient. Something… something for the
future. Something to think about but I’m really happy with this. I hope you guys
are inspired to get out there and you know… make something cool and you know… a
lot of people are like “Oh, you need a patent.” “You need to do this.” “You need to do that.” – This isn’t a new concept. I mean… This was the same exact idea from Honey
I Shrunk the kids came out with 1985 or something like that. It’s not… It’s not a
new or novel idea. I can’t patent this. If I came up with my own system… my own
custom system for mounting or driving or something like that,
I could probably patent that but I think I’m gonna keep doing stuff like this…
keep improving the design and see where… see how this takes me. Thanks for
watching and I hope y’all have a good day. Bye!

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3 thoughts on “How To Build a Remote Controlled Lawn Mower

  1. Hey. I’m christys brother. She lived down where y’all are but now she’s back in ky. I was the one in a car wreck and now I’m a wheelchair also. I’m building one of these but kind bigger. This is really helping me. Thank you for the vid

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