Hopefully this is a short video about the catapult launcher that I've built with PVC pipe. This was basically a design that I found on the internet and made my own modifications. I've had people ask about dimensions and so forth and how the trigger works. So I'm going to show you this. Hopefully I have an all PVC frame and a wood plank is used as the trigger. The power comes from a 6mm silicone tubing. This is 10 meters of this folded in half. There is an anchor. It's a screw-type anchor for dog leashes. This was recommended on the internet but the ground out here is too hard. So what I do is I just lay it down and use the big heavy spike and put it through the ring. On the opposite end of the silicone I have a ring connected. There's a ring connected and the yellow flag piece of ribbon is just there to help find the end of it once it's launched. Then there's a piece of nylon string. The purpose of the nylon string is it's not stretchy. So the ring that's on the silicone is attached to the trigger. Then the ring that's on the end of the nylon string is attached to the plane. It's two stages. And this particular one has a slip knot tied into it so that I can adjust it for a positioning of different planes. So that's the silicone bungee part of this. Launch part of it and now I'll go over the specifications for the frame. You'll notice the top part has this flamingo pink. That's just some duct tape to help reduce the friction on the top of this and get it to last longer. I picked a pink just for visibility for other folks that are out in the field. Just a note, none of this is glued together. One of our club members, Frank Bell, suggested that we put it all together with screws. So that we need to take something apart and adjust it we can. And that's already turned out to be a great idea. So just a bunch of half inch to three quarter inch screws are used to attach all this together. There's probably a simpler way to do this. I didn't draw it out or anything. I just laid it out and started screwing things together. So let's go into the dimensions. The dimensions are not going to be absolutely critical so I'm just going to call these out. This is the front and the total length of the front is 29 inches. The width on the front is 23 inches. This piece holds the trigger to the front crossbar. The trigger pin is 13 inches from the front of the crossbar. This is just a four way PVC. All of the PVC is three quarter inch schedule 40 PVC. What I did on that particular piece is this is the trigger pin. So the bungee is going to attach to this. What I did is this is a three and a half inch hook by one quarter hex head bolt. I drilled the hole all the way through this four way and attached a nut on the inside and a nut on the outside to hold it. And then I just took a saw and cut the head off and a grinder and rounded off the top. So that's how I made the pin. So this part here has no threads on it at all. This piece just adds a little more stability. It's seven inches long. I've had questions about how the trigger works. So I'm going to go ahead and demonstrate that right now. This shows how the trigger is put together. The quarter inch bolt comes through a hole in the board that's used for a trigger. The ring that's attached to the silicone is slipped over that and stretched out. Then the pink line goes up to the airplane. So what happens when you step on the board at the opposite end, the board simply pushes the ring up off the edge of the pin and that releases the silicone tubing. Real simple device. The trigger is a piece of one by four board and it's attached to a piece of two by four so I can raise it up and get a little more throw on the trigger. And then it's attached with one inch pipe clamps to a crossmember on the frame. The trigger hinge point is mounted 34 inches from the rear of the launch frame. Of course all of the crossmembers are going to be set so that the pipe to pipe width is the same. So from here to here on the centers of the pipe is 21 inches. Okay I'm going to do the total length. I've aged seven inches long on the bottom. Total width including the junction pieces is 23 inches. The height from the ground of the back is 14 and a half inches. The height of the front from the ground is 30 inches. Now those the front and the back of this slopes backwards are not vertical. It's just a function of the ramp because the ramps themselves have 90 degree bends on each end. So since the back is shorter than the front then that makes some sweep back just a little bit. Here in the back of this you can see the T that's in the center. What I've done with this is I drilled a hole all the way through that and then one of the long spikes is driven through that. When I first set this up then what I do is go ahead and set up the silicon tubing and hook it up to the trigger which is up there. So once I've got that hooked up to the trigger what I can do is kind of adjust the front position so that everything is in a nice straight line. I want everything to be in a nice straight line. The silicon tubing coming up to the trigger point and then the trigger board coming back and then coming into the stake at the back. Once that's all lined up by shifting the front left or right then I've also added holes through the front on each side and those long stakes go into that as well. By putting the long stakes in I put two in the front one in the back and that gives me three points of contact and holds it down really good. I bought some of that tape that has sandpaper kind of stuff on it just so that when you step on the end of the trigger your foot doesn't slip off so that's what's on there. So that's it I think. Everything you need to build a bungee launch or a catapult launch.