Radio Control Lawn Mower with TANK TRACKS – a build by VOG (VegOilGuy)
Hi YouTube, my name’s Geoff and I’m the
VegOilGuy. Grass. Well, weeds and grass. I hate cutting
both. So I came up with the idea of building a remote
control lawnmower and the wife agreed to cut the lawn whilst I was building it.
And that was 15 years ago. Okay, not really. In truth it was last summer.
Now it’s not finished yet, but it’s ready enough for a test run…
So I quickly rigged a temporary board, then loaded on the batteries and electrical bits.
Not bad eh? Okay it’s a bit too low – the blade is
catching the ground a little, so it needs raising maybe half an inch, but it works.
More importantly than that, to me it looks really good.
And even more importantly than that, everyone that sees it wants a go at driving it – so
I’m still not cutting the lawn. It’s quite difficult to do my usual step-by-step
instructions for this one as we all want different things. For example, you might prefer wheels
to caterpillar tracks, and your mower may be completely different to mine.
So here’s an overview of what I’ve done so far.
This is a self-propelled Honda petrol mower. I wanted petrol, not electric, so as to not
tax the requirements of the batteries. And whilst this one is self-propelled, that’s
not strictly necessary. I started by giving everything a quick clean
and removing the wheels and handles, but I didn’t cut any cables just yet.
One of the first obstacles I had to get around was the safety cut-off. This model had one
of those handles that needs pushing forward, the sort just about everybody ties in place
Come on – you know you do. Well without handles I needed to secure the
safety mechanism in place. This is easy enough. I followed the cable down to this little lever
and it was just a matter of squeezing it, which I did with a nut and bolt.
That got rid of that cable and safety feature, but for the health and safety minded, I’ll
be building in another safety system later on, though not in this video.
The engine is a typical pull-cord variety, and the fuel control lever needed attaching
to something, so I used the old handle to make this shorter version which I bolted through
the body. I emptied out all the oil and petrol, then
turned the mower on its side. Underneath was in fine condition, just a little surface rust.
There’s a belt hidden behind the blade that turns a few cogs in this gearbox to drive
the wheels, but it would be no use to me, so I removed the blade, belt and gearbox.
I rubbed down the loose rust and gave everything a coat of anti-rust paint.
I want to retain the option of attaching a grass collector and this model throws the
cuttings out of the back. But it’s very one-sided and I knew this might give me motor-fixing
issues later on, so I set about centralising the hole.
Cutting away extra metal with the grinder was easy, but I took care not to remove any
structural strength. Of course this left me with large gaps that needed filling. I could
have used sheet metal but I had this length of 4 inch waste pipe to hand. I cut a straight
slot down this, applied a heat gun, then straightened the pipe out into a nice, solid sheet of plastic.
I cut this to shape and bonded it in place with car body filler. I was so pleased with
this I got carried away and painted it up too soon in honesty, as I hadn’t recorded
the other side, but it was the same process, plastic, filler and paint.
I took my angle grinder and cut away the majority of these welded-on brackets, roughly smoothing
things out with car body filler. Where the wheels had been removed, I was able
to bolt in some 12mm threaded rod. I knew I’d need to suspend the mower somehow and
this seemed a good starting point. To power the mower along, you need a couple
of motors, and I opted for wheelchair motors as these are strong, reliable and reasonably
priced second-hand. It’s important these are brushed motors and the emergency brake
is best removed. How these motors get attached is largely down
to how you want your mower to be steered. Some folks opt for a skid steer system.
Some folks opt for shopping cart wheels on the front.
Others go for the more complex option of creating a steering mechanism to turn the front wheels.
In all of the above, the motors can be mounted onto the body of the mower in some way.
I wanted the extra traction associated with caterpillar tracks and – let’s be honest
– I thought they looked really good. This meant I needed a little extra room. So
I built a simple frame from 1 inch box steel that was just a little bigger all around than
the mower. I designed my caterpillar tracks from scratch,
coming up with a fairly simple design that could be manufactured with the most basic
of tools and yet give me all the articulation I was looking for. These tracks had to be
driven by a sprocket connected to each motor, and these I cast myself using my lost foam
casting technique. The motors were bolted to the rear of the
frame and the sprockets were bolted to the motors, but I still needed to connect sprockets
at the front of the frame. At the time I came up with this simple T fixing which was a mistake
I’ll talk about later was. These simply bolted to the frame.
I also casting some support wheels to help carry the weight of the tracks and prevent
overdue strain on the individual links on rough terrain.
I decided to use this to suspend the mower from the frame and also provide a means of
height adjustment. I connected simple uprights to the 12mm axel
rods, then placed the tracks and frame around the mower.
I was then able to exercise my terrible welding skills to wrap the box frame uprights with
slightly larger box section, welding this to the outer frame.
By drilling holes in these uprights, one at each corner, I was able to slide a bolt through
to successfully suspend the mower. More holes could be drilled at intervals to provide height
adjustment. The advantage of this set up is that the mover
is not permanently fixed in place. With the bolts removed, the frame and tracks can be
lifted up and off, leaving the mower behind. And that’s pretty much where we came in
at the start of this video. It was looking good, to me at least, and though
I’d tested the tracks quite heavily, they’d never carried the full weight of the mower
before. So I added a temporary shelf, strapped down
the two car batteries, hooked up the radio control gear and gave the mower its first
test run. It genuinely thrilled me.
It ploughed through the grass with ease, kicking out clouds of cuttings. The blade was clearly
too low, so I need to drill some lower bolt holes to adjust the cutting height. And even
though I scalped my lawn in places, I couldn’t resist playing with in for a couple of hours,
with no sign of the batteries getting tired. However, this was its first outing as a mower
and the blade height was not the only problem. If you look carefully here, you can see the
forces involved have bent the 12mm bolt holding the front sprocket in place and this is twisting
the tracks. I think I’ll upgrade to 16mm and cast a better support mechanism.
I’ll also tidy up my terrible welds, add strength and try to deduct some weight if
I can. I also want to add a safety cut-off feature
in case the mower ever goes driving off without me.
I’ll properly house the batteries and electronics, as well and set up an easy means to charge
the batteries without unnecessary swapping of cables.
But those things will take a little while to get around to, and the good news is the
wife can cut the lawn again. I’m sure she’ll be delighted.
I’ll share any updates in future videos. So I hope you enjoyed this show and tell guys.
If you did, please like it. If you have any questions about the process, drop me a line
and I’ll do my best to help. Please look out for my other videos, my YouTube
Channel and my website. So that’s it for now guys, thanks for watching.