Hey guys welcome back
Thanks for joining us today on the king of random. The crossbow is a weapon and tool that dates back
Thousands of years and has been used for hunting and warfare.
It has great range a lot of power and often takes less training to learn to use wealth and other types of bows. The purpose
of today's video is to learn how we can build our own crossbow using a 2x4 some PVC and some paracord
We also have a couple of wooden dowels and a small piece of 3/4 inch plywood. In this video,
We'll be using two by four PVC and paracord to build the body and bow of our crossbow.
In our next video, we'll cover how to build the trigger mechanism and the arrows. Let's get started as a first step
Let's measure 2 feet from our 2x4 and cut it off with the chop saw. Well. I've got my chops
I'll I'm also gonna cut off two pieces of my 3/4 inch schedule 40 PVC
One piece will be 30 inches long and one piece will be about 1 foot long
With these pieces cut there are some more details that I need to add to the body of our crossbow,
so it's not just a block of 2x4. I'm going to draw those out with a sharpie and then cut them out with a bandsaw
This is going to be the front of the crossbow and this will be the back.
This notch up the front is where our bow will sit
Resting against the body of the crossbow. This piece that I'm removing is to create a handhold right here
Where it can hold on to the front of the crossbow this larger piece is being removed for two purposes.
First it makes the crossbow a lot lighter. Second, we'll have our trigger mechanism on this part of the crossbow
There we go. We've got the basic shape of the body of the crossbow.
Now, I'm going to use the belt sander really quick and take down a lot of the sharp edges and plane out the top of it
so it's a little bit flatter and smoother.
The body of the crossbow is cut out. It's sanded, it's smooth, and comfortable to hold now. Let's move on to making the bows
Clearly to start out with our PVC pipe is round and we want it flat so what we're gonna
do is we're gonna take our heat gun we're gonna heat up the pipe
And then we're gonna smash it flat using our vise
Now the clamps of the vise are not as tall as the PVC pipe and it has this knurled texture
Which helps you get a lot better grip
But we don't want that texture smashing into our PVC so what I've done is I've thrown together a couple of blocks
Using two by four and just glued a couple of scraps of wood onto the top
these fit nicely in the vise and I can fit the PVC pipe between them and smash it there
That gives me a much larger surface area
And it's a lot smoother than the gripping services of the vise.
Now with our heat gun, we want to heat up the PVC pipe four or five inches of length at once we want to make sure we keep the heat gun
moving and the pipe rotating so that we don't burn it in any one spot
With your PVC heated up we want to sandwich it between the two blocks.
I'm just going to smash this down until I can't really smash it any farther.
Now the PVC is somewhat elastic so if we were to unclamp it right now
We can see that it will start springing back to its shape and that's not what we want
We want it to stay flattened the whole time so what we need to do is leave
it clamped as it cools down if it cools down while it's in the clamps
It will hold its flattened shape while this portion is cooling down. We're going to warm up the next four or five inches
As you heat up the next length of the PVC be sure you support it at the back so that it doesn't sag down
When the PVC is warm it could even tear if you let it sag too much
All right
Got some good squishiness flexibility.
Let's loosen our clamps
I'm just gonna kind of push it through you can see it's kind of getting squished on its way through and I'm not going to
Push it all the way through so that the already flattened portion is completely out of the clamp
I want to sort of use that to make sure I don't end up twisting as I go
If I use this as a guide it will all stay flat in the same plane
It starts taking longer the farther down you go because the wood blocks themselves
Get pretty hot and PVC really needs to cool down while it's sandwiched in between them
Which is harder for it to do when the wood itself is not cool
you can see here that I got a little bit of a bend in the bow and I want to take that out because I
want it to be a little straighter, so I'm gonna try reheating this portion just
Bending this end part down a little bit. We'll see how this goes
It is letting it Bend now, although it's also
Puffing back up kind of taking on more of its tube shape again, which is not really what I wanted
I'm gonna help it stay flat. I'm just gonna sandwich it between a couple boards here. It's a waiting game now
There we go we've got
The first piece of flattened PVC which will turn into the main bow on our crossbow?
Now let's do the same thing to our one foot piece
While our smaller bow is cooling down in the clamp
We're gonna work on shaping the main bow for our crossbow
The first step is we're going to try and heat up this piece of flattened PVC
About 2/3 of the whole bow here in the middle. We'll leave the ends cool the way they are for now
Similar to when we tried to adjust the curve in the bow before
it's likely that some parts of the PVC will start to split apart and
Lose the flattened shape that we've given it as we add the curve. Hopefully the pressure of bending it will flatten it back out
So you know we're doing I'm gonna try and add just a gentle curve into the whole bow
Don't want it to be too extreme. We don't need any sharp angles or anything
And I'll give this a few minutes to cool off and hold its shape
Now we have a nice curve in the PVC which is going to become our primary bow but to give it a little more strength
We're going to try and add a little bit of recurve on either end this will make it so as the bow is pulled down
It not only has to bend on one side, but it has to straighten out the edges this will give us a lot more power
That feels fairly flexible
You can see it started to sort of balloon out. I think as I wrap it around the fire extinguisher
It will just smoosh it back down pretty well
Down enough to hold its shape do the same thing on the other side
All right there we have it there's our primary bow
It's a good curve in the main body of it, and then some recurve on the ends
This second piece of PVC is actually going to be a second bow that goes on our cross foot
This piece of PVC with its curved and recurved ends will give us a fair amount of force
but it is still PVC and traditional crossbows would use either a
laminated wooden bow or a metal boat to give it extra strength
Since PVC isn't as strong as either of those there's going to be a secondary bow on top of the first one
curving in the opposite direction a
Second string will connect from one
End of the large bow over the smaller bow and then back down to the other side
So the same way we did with our large bow we're now going to heat this up and add a gentle curve to it
All right
Add a slight curve into this
Some of you may recognize our original backyard foundry. I'm just gonna use this as a curved surface
to wrap this bow around
Here we go we've now got our two separate bows
And we need to attach these to the top of our crossbow in order to find out the exact center of the bow I'm gonna
Put it on this stick and try and get it to point where it's perfectly balanced. It'll mark that point
Let's take our larger bow and line it up on our two-by-four body
And we're gonna want to pre-drill a couple of holes that go through the bow and into the wooden body
The large bow will go right here where we've just drilled it out
The small bow will face the other way so they curve in opposite directions
With these two bows set up the way that we want them we're going to drill through the holes that we already put in our
Larger bow and down through the smaller bow to make sure the holes all line up exactly where we want them
With our screws driven just slightly through the two bows we can now align the two screws with our
Pre-drilled holes on the body of the crossbow
Those fit pretty well, let's temporarily remove the screws in the bows and then make our modifications before we reattach them
On the larger bow we need to add notches to allow for the connection of our bowstring
For decorative purposes, I'm also going to cut off the very edges of the bow at an angle
There we have it that should work great
Our smaller boat doesn't need to be cut in the same way to hold the drawstring
But we are going to sand some grooves into both sides
So that as a drawstring passes over it it will stay centered the way, it's supposed to
With the modifications complete on both bows let's reattach it onto the body of the crossbow
The bows are complete they're added to the body, let's try adding some bowstring here. I've got some paracord
I'm going to tie a loop in one end measure out the correct length and then tie a loop in the other end
you need to be sure that the loop and your knot is large enough that it can fit over the knots you've cut into your
bow
Now we also want to make sure that when our bow is strung
There's already a little bit of tension on the bow
So I'm going to pull slightly on the bowstring if you can see that the bow starts to give a little bit
That's the length we want the paracord to be where we add the other loop
Cut myself off plenty of extra here if you keep your knot nice and loose you can easily adjust it as you measure
That looks like pretty good spot make sure that I've got enough loop fit around the notches
There we go it's under a little bit of tension we can see it if I draw it back
It Springs forward, so I think that is a good length of bowstring right there now
I'm just gonna cut off the excess here, and then I'll fuse the end of the paracord using a lighter
Now like I said this has some spring to it
But not as much as we want so we're going to add another string that goes from this end of the bow
Up on top of the second bow and then connects again to the notch on the other side
Take our paracord make sure our end is sealed off
Start with another bowline knot
slip that over the notch on one side
And you measure going across the top
down to the other side
Now I haven't tied it off yet, but if I just wrap it around a couple times
You can already see that now when I pull on it this cord going along the top is
forcing the second bow to
flatten out which adds a lot more tension into our crossbow now we want to tie another loop in the end of this piece of
Paracord so that it's quite snug as it wraps around this knot
To make it a little bit easier to attach the second string you can put it on the notch
Without it being over the bow and then stretch it over one side at a time
There you have it
that's how you can build your very own crossbow using a
Two-by-four for the body some PVC piping for the bow and some paracord for the strings like I said in our next video
We'll go over how to build the trigger mechanisms and the arrows that used thanks for joining us for this video
And we look forward to teaching you how to finish your crossbow in the next one talk to you then
That is toasty holding on to that little part in between the blocks. I'm sure it's still very one