Launch Pad Construction - Assembly
Assemble the sliding collar turnbuckles. Thread a #10 nut (same size as 3/16 turnbuckle screw) onto the right hand threaded eye on the collar. Slide the inside star washer on top of the nut. Thread the turnbuckle onto the eye. Set the turnbuckle to the smallest size possible.
Repeat for the second side. Set the turnbuckles to the same length.
Slide the collar onto the sprinkler riser and make sure the copper straps go inside the 1 1/4" coupler. Bolt the turnbuckes inside the handle. Use the 5/16 x 1" bolts from the inside and the nylock nuts on the outside of the handle. The bolt should be snug on the turnbuckle eye but allow a full range of motion of the handle without binding the turnbuckle.
Clean the top ends of the copper strap. Insert the launch tube into the head without a gasket. Slip a soda bottle on. If you you a large diameter bottle neck then your system will need less work. Hold the handle down all the way in the locked position. Hold the bottle all the way down. Now mark the copper strap where the top of the bottle neck is. See drawing below where parts are removed for clarity.
Remove the bottle after making the marks. Raise the handle. Remove the launch tube. Mark the copper strap again 1/4" above the first mark.
Now cut the end off the copper straps to the top mark. That is the second mark made 1/4" above the first mark. Bend the copper straps inward using needle nose pliers making a 90 degree bend of an 1/8" hook. Don't worry about a round corner. The dimensions are just to make a firm foundation for the plumbers' epoxy putty which does most of the work for holding the bottle. The copper strap will not be in direct contact with the bottle.
Clean the copper strap ends very good. Prepare the work space for the epoxy appliation. Cut two 4" squares of plastic wrap. Get some paper towels and protect the work surface. Rubber gloves will protect your hands from the epoxy but I don't use them. The epoxy can be rubbed off your fingers after molding the parts. Its up to you, there is no harm in using your fingers.
Replace the launch tube and the bottle on the launch pad. Raise the handle and slide the bottle up and out of the way for a moment. Cut off about 1/2" of expoxy putty and mix according to the directions on the package. When the putty is mixed well it will feel warm in your fingers. Break the epoxy into halves. Take one half and smear the epoxy on onto the hooked end of the copper strap. Work in on the strap until it adhears to the copper leaving a residue even when you pull the epoxy away from the strap.
Form a ball of the epoxy onto the end of the copper strap completely encasing the hooked end. Cover the end with a square of the plastic wrap. Repeat for the second side.
Push the bottle down into place and clamp the handle down. Guide the epoxy ends of the copper straps so that the plastic wrap remains covering the epoxy. Guide the expoxy ends into place as you clamp the bottle down fully so that the epoxy forms around the neck of the bottle. Push the epoxy down into the neck area since it will tend to be pushed up and out of the neck area. Form it while it is still plyable because it will harden in about 15 minutes.
Let the putty harden to a point where it still holds its shape if you push on it with your finger. But you should still be able to mark it with your finger nail. Release the bottle and remove the plastic wrap. You will see the putty formed to the bottle neck and a big indentation where the catch on the neck is. You must now take a knife and trim the putty so that there is no putty underneath the catch of the neck. The outside of the putty may also have a ridge where some of it was above the 1 1/4" coupler. That ridge must also be trimmed off now. Imagine that the putty must be free to move all the way inside the 1 1/4" coupler without catching and the bottle must be caught from the top down having no putty underneath the catch on the neck.
The first picture shows how the putty first forms and the second shows how it must be trimmed. Trimming can be done with files and sandpaper after it hardens but that is not pleasant. Trim it while it is soft.
The highlighted area is the shape to keep. Trim off the edges.