So in our previous video, we tested the launcher.
And we noticed that, several times, the launcher
threw the ball towards the left, and we
wanted to see if we could straighten that out.
So we took a look at some different key components.
You can see those in red.
We have our 5/16 stop pin or bolt
and our PVC cradle that holds the ball.
Now currently, what happens is you pull the bar back,
and then the ball goes back with the bar.
And then you release the bar, and the ball
travels forward with the bar.
And then the bar hits the stop, but the ball continues on.
So what we wanted to see if we could do
is remove the pin and the cradle.
And one of the reasons is that the pin can potentially
be a pinch point, and it also has the effect
of building up stress in a very specific point on the aluminum
bar there.
And that stress can work harden the aluminum.
It actually changes the crystalline structure
of the metal over time and causes it to be more brittle
and can eventually cause it to crack.
And so we were going to see if we could launch the ball using
the same kind of technique that a football kicker would use.
So there would be a guy holding the tip of the ball in place,
and the kicker would wind up and then kick the ball.
And instead of the ball travelling with his foot,
he would instantaneously contact the ball that's being held
in a certain point, and then the ball would release.
So we thought it might be interesting to design
a device that could hold the ball in place,
like the guy that holds the ball in place for a kicker.
So we thought maybe we could take a paper clip
and bend it to create a device, shown in purple here,
to hold the ball in place.
And then we could remove the cradle and the stop pin
and maybe improve the accuracy and longevity of wear
and maybe even the safety of the device.
So we started with the ball.
We put it in its location.
Then we took a needle-nose pliers and a paper clip
and started bending the paper clip
to create a larger loop at the top and a smaller loop
at the bottom.
The overall paper clip shape is a C shape
when you look at it from the front of the device.
And so it took a little while to figure out
exactly where to position it, and we
drilled a hole in the side of the wood
and put a panhead wood screw in there
to hold the paper clip in place.
And then we put a little loop at the bottom
and put another screw there to just ensure
that the paperclip would be nice and secure.
And so once we had the paper clip in place
and it was connected, we put the ball in
and tried to make sure it was lined up correctly
so that the launcher would hit it.
And at this point in time, we still have the PVC on there.
We're still looking at experimenting with the PVC.
We will eventually remove that because it, with the paper
clip, ended up causing the ball to launch to the side.
So we'll do a quick launch here and just check it out.
So we decided to do some field tests,
and we recorded the distances and the height
and the different angles and positions
that we launched the ball at.
And we did this a number of times.
We had a little sand trap set up so we
could see exactly where the ball had landed,
and then we recorded that and tried
to figure out if we could improve
the launcher in any other ways.
And we noticed that there were a couple of opportunities
for improvement, so we went back to our drawing
and made some adaptations.
Finally, we were looking at our design,
and we discovered that, as we launched
at steeper and steeper angles, like right here, when we're
setting the device at steeper angles-- at 50 and 60 and 70
and 80 degrees-- the top section of the device
tended to fall backwards or lean backwards.
And so when we were launching the ping-pong ball,
it was hard to reliably launch it
without that top part moving.
The other thing we noticed is that we
wanted to grab the launcher to stabilize it,
and we tended to want to grab it right here, which
is great except for the fact that when the aluminum
bar swings back, it can smack your hand on this part
right here.
So we wanted to make sure that that wasn't going
to be a possibility, and we wanted
to find a way to keep this top piece down.
So what we decided to do was to create these features.
So we have a bolt that we've cut a little bit short.
It goes right here.
It's a 5/16 bolt.
And we have a nylon sleeve that goes around it,
and that keeps the launching apparatus or the top piece
from coming back or leaning back when it's at a steep angle.
And then we used 1/2-inch plywood to create a cover
for the spring assembly area.
And we cut a hole out in it so you can still
access that bolt if you need to loosen or tighten it,
and cut a half a hole here to do the same with this bolt.
But this way, you can pull the launcher back,
and there's no chance of any kind of being pinched or caught
in any way.
And so those are the main innovations on the launcher
there.
So now I'm going to spin it around
so you can take a look at it from a number
of different angles.
You can see there are one, two, three, four main pieces of wood
that hold the cover in place, and then we have our bolt there
with the sleeve.
OK, so now we're going to see what
we can do to improve the launcher
and make those changes.
You can already see the bolt with the sleeve is in place
there to prevent the launcher from coming back too far.
And now we're going to measure the top part
of the cover that's going to go over the spring assembly.
That'll be 6 and 1/2 inches wide,
and then we've got a 1-inch spade bit
that we're going to use to drill out the holes for the bolts.
So that's the center bolt and the spring bolt.
And so now we're just marking the positions.
We're drilling those bolt holes out and cleaning that off.
And we're going to set our fence up,
and that fence will allow us to use the circular saw
to cut a nice straight edge.
And we use the piece of wood there
to make sure that the fence didn't
interfere with the clamps.
So now we're just trimming it down to the right length
and cleaning off the edges with a file.
And now what we've done is we're cutting the side pieces.
Those are an inch and 3/4 high, and they go all the way
around the edge of that box.
And we're cleaning those pieces off.
And they're 6 and 1/2 inches wide.
Then there's one piece that's 13 inches wide,
and that's the piece that runs along the long edge.
And so now we're just clamping those in place.
We've already marked them 3/8 of an inch up.
We're drilling our holes with a 1/16-inch drill bit.
And now we're just putting inch and 1/2 panhead wood screws in.
And we screwed our top piece on already,
and now we're going to put the bottom piece on.
And just lining that up, using the clamps to hold it in place,
and again, 3/8 of an inch up.
And we're just putting those screws in.
Now we're going to go ahead and put the top part on.
And we're, again, pre-drilling all those holes
and using our panhead wood screws, putting them in.
So we have everything lined up.
The hole in the center wasn't as clean as we like,
so I'm going to take a Dremel and go back and clean that hole
up, make it a little bit smoother
so that it's sure that we're out of the way of the bolt below.
So I'm going to take the cover back off,
and we're going to assemble the hardware inside the device
again.
So you've seen us do that before,
so that's not anything really new.
We're just tightening down our bolts
and making sure everything is secure.
And then we're going to tighten down
all the screws for the new cover on the launcher
and make sure that it works.
Now we're shortening the bolt that we need,
which was that little green bolt that was in the drawing,
and cleaning it off with a file.
So that's just going to make sure
that the major piece doesn't fold back
when it's at a steep angle, and so that's the part right there.
And there's the original bolt down below.
We've got our paper clip that holds the ball in place
and keeps everything lined up, and again, we've
got our countersunk holes.
We can drop the device completely flat.
And I'll just turn it around here for you
so you can see all of the different components
and how it looks and works together.
And we'll set that angle bolt in,
and then we'll put the other bolt and its sleeve in place.
And so now we're going to test fire it.
Put a ping-pong ball in, and we got a successful launch.
So now we're going to go test it in the field.
So we've got our projectile launcher set up,
and we have our numbers indicating the height
on the back in the black plastic there.
And then we have our tape measure,
so we can measure how far it goes, or our range.
Initially, we're going to set at position 4, which
is the fourth position back from horizontal, and angle 20--
so 20 degrees.
And you can see where the ball lands out there.
We went out and measured it in the sand.
The sand lets us see where the ball landed.
So we're at 30 degrees and the same position--
so the fourth position down.
And now we're at 40 degrees-- again,
seeing that the ball is going up higher.
Now we're at 50 degrees, and again, the ball
keeps going higher.
And the range of the ball is decreasing,
and the height is increasing.
And so now we're at 60 degrees.
And as we go higher and higher, the ball
tends to veer off a little bit.
Now we're at 70 degrees, same position.
The ball completely goes out of the screen,
and again, it's not quite as far away.
And now we're at 80 degrees.
So we're going to take a look at precisely measuring exactly how
high the ball goes.
The sand measures our range, and we can slow the film down
and see that the ball went just below 3 feet.
The top of the paper is exactly 3 feet,
so the ball was about 2 feet 10 inches on that particular shot.
So we're going to try another one.
And on that one, again, it was at 20 degrees, position 4.
We can see the ball goes to about 3 feet
4 inches on that particular shot.
So that allows us to see the height,
and we can use that in our calculations.
Now we're going to see if we can use this information
to knock down a tower of cups.
So we've got it all set up.
This is position 4, 20 degrees.
Yeah.
Only three tries.