Hi! I'm Zuzu from Design Squad Global
and this is Kyra.
We're here at the East Boston Y.M.C.A.
to check out their garden.
ZUZU: You got it?
I got it out!
My first one.
ZUZU: The kids at the Y.M.C.A. grow vegetables
and make food in their kitchen.
In cities, there isn't a lot of space,
so they make the most of their space
by using one bed to grow their vegetables.
Their garden needs healthy soil to help the plants grow.
Right now, they have to buy compost,
which is a mixture of vegetable and organic waste,
to fertilize the soil.
The kids at the Y.M.C.A. told us
it'd be great to have a compost tumbler
so that they can make their own compost.
A composter is made of simple machines
that make it easier to spin the compost
so it gets easily mixed.
Mixing helps food scraps like fruits and vegetables
turn into compost to help feed the soil.
We're at Parts and Crafts, a maker space for kids.
This is Dave.
He's a carpenter and builder,
and he's going to help us build our compost tumbler.
We're using a recycled rain barrel
for our compost tumbler.
This should hold enough compost for the garden at the Y.M.C.A.
First, we brainstormed ideas and sketched our designs.
We were talking about having something
stick out from the barrel.
So the axle would be coming out of it.
The frame would be here and supporting that.
ZUZU: Our design uses two X-frames
to support an axle
that runs through the center of the barrel.
This allows the compost tumbler to spin and mix the compost.
KYRA: This is 35.
ZUZU: 35 it is.
We measured all the parts of our design
so that we could start building.
We're making our frame out of two-by-fours.
(saw buzzing)
Our frame is two Xs linked by two braces.
We're using PVC pipe for our axle.
Our axle will run through the center of the barrel
and rest on our frame.
(saw buzzing)
Now we need to find the exact center
of the end of the barrel
so that we drill our axle holes in the right spot.
First, we found the center of the Y axis,
and then we draw our X axis line
and we found the center of the X axis.
That'll give us the center for the barrel
where we can drill the hole for the axle.
DAVE: Good job.
ZUZU: We're installing a hatch
so that we can access the compost.
We're designing a hatch that's big enough for a shovel
and that's easy to reach.
DAVE: So not up here.
KYRA (laughs): No. DAVE: Okay.
(laughs)
ZUZU: We use nuts and bolts to attach the hinges.
The hinges allow us to open and close the latch
to access the compost.
Compost has lots of organisms, like bacteria and small animals,
that help turn the vegetables and plant scraps
into compost.
These organisms breath oxygen, so the compost needs air
to help it decompose.
We're drilling holes in the side of the barrel
to add air to the compost.
The reason that a compost tumbler tumbles
is to mix in air to speed up the process
of breaking down the waste.
All right, so now we need to come up with something
that will mix the compost.
KYRA: Yeah, if we have fins varying in different places,
it will agitate the compost more.
ZUZU: Kind of like a washing machine.
We're making our compost-mixing fins
out of PVC pipes that we've cut in half.
Okay, cool.
We're varying the size and spacing
of our fins inside the tumbler
so the compost will be thoroughly mixed
when the kids at the Y.M.C.A. turn it.
I like your guys' placement-- good job.
So this is a 55-gallon drum,
and when this is filled with dirt,
this thing is going to be pretty heavy.
KYRA: We added a crank handle to the barrel
so it's easier to turn when it's full of compost.
The handle acts as a lever,
rotating around a center point called a fulcrum.
By using a lever, we multiply the force
we're able to apply to turning the barrel.
(laughs)
Oh, that's so fun.
ZUZU: We added furniture legs
to make it look like a pirate ship wheel.
DAVE: Beautiful.
That's a cool compost tumbler.
ZUZU: Now it's time to show the kids at the Y.M.C.A.
their new compost tumbler.
BOY: That's cool.
ZUZU: Now the kids at the Y.M.C.A.
can use their new compost tumbler
to convert their food scraps and garden scraps
into compost for their soil,
so they can grow lots more vegetables
in their garden.
Do you have an idea for a device that can help out in the garden?
Send us your ideas to the Design Squad Global website.
Design Squad Global!