The World's Fastest Raingutter Regatta Boat

Instructions for building your own

Warning and Disclaimer:
Any attempts to replicate, or improve upon, our rocket-powered boat should only be done by adults or under strict adult supervision! All such attempts are your responsibility and we are not responsible for any maimings or killings resulting from your ineptness or stupidity! The kits used and described below were highly modified and are not designed for what we did to them. Therefore you are on your own in terms of liability!

Introduction

You should read these instructions completely through at least twice before attempting to build. Like most red-blooded American males I often scoff at instructions, but in this case your safety and the safety of children are at stake. Please be careful. If you don't understand something after reading the instructions and looking at the pictures, don't attempt to go any further. Skipping a step may result in the catastrophic failure of your craft which may be spectacular, but then again may be horrificly injurious. Do not take the above "Warning and Disclaimer" lightly, we mean every word. Even though we kind of flew by the seat of our pants (no pun intended) designing and building this boat, we always kept the safety aspect in mind.

All that being said, this project was great fun. You don't need sophisticated tools to do it; after all, we built the thing on a picnic table using all hand tools. In fact, we didn't have a dovetail saw and actually cut the hull with a hacksaw. In the end, even though a lot of brain-power went into designing and building, we were quite astounded at how well the boat actually worked.

So, let's get started!

We figure we had about $35-40 (USD) in this thing. The car kit is about $20. The boat kit $4. Extra engines are about $5/package and we bought 2 packages. The paint, sandpaper, adhesive, aluminum, etc. came from home in our case, but if you had to purchase them you'd probably spend another $10-20. So you can't get by on the cheap doing this.

Boat Modifications

1. Measure and mark the center of the stern (rear) of the boat hull.
2. Mark a line from the point of the bow to the above mark on the stern.
3. Using the dovetail saw, cut on the line, holding the saw as square to the hull as possible. Don't worry if the hole for the mast doesn't line up with your cut line, it probably isn't centered anyway.
4. The curved sides are now the bottoms of the new catamaran hulls and the straight sides (which you just cut) are the tops. The two halves probably don't have the same curve profile. Hold or clamp the halves together so they match straight edges and rub the curved edges over the 100 grit sandpaper until the curves match.
5. Rub the straight edges over the sandpaper to smooth out the saw marks.
6. Sand all surfaces with the 220 grit sandpaper to prepare for painting.
7. Hold or clamp the hulls side-by-side and make a mark on each hull about 1.5 inches from the bow.
8. Draw a line across both hulls at the marks.
9. Using the dovetail saw make 2 cuts about 1/16"-1/8" deep, one on each side of the line. The 2 cuts should be right next to each other so that, when completed you have a square groove about 1/8" deep and 1/8" wide. This groove will be used to mount the rear axle of the car which is used as the front brace for the hulls.
10. After step 3 below, cut a piece of the mast dowel the same length as the axle. This will be the rear brace and body mount.
11. While the hulls are still together mark each hull about 2" from the sterns. Draw a line across each hull at the marks. This will be the location of the rear brace when glued to the hulls.
12. Discard sail, rudder, and keel. You may want to save the number decals for application later.

Car Modifications

1. Remove car from guide string.
2. Remove the engine mount from the car by squeezing the clip on the bottom and pulling straight down. Save this mount.
3. Using the hacksaw, cut off both rear wheels right at each wheel. File the ends of the axle smooth. Discard wheels and save the metal axle.
4. Using the hacksaw, cut off the nose of the car right in front of the "Estes" decal. Discard nose.
5. Using the hacksaw, cut off the rear of the car using the cockpit headrest and the silver "straps" on each side of the car behind the cockpit as guides. You will be left with the entire cockpit and all of the headrest behind the cockpit.
6. Using the hacksaw, cut off the wing from the rear of the car. Cut straight back from the front of the wing so there will be an angled "pylon" under the wing. The wing will probably come apart at this point and may be glued back together with the epoxy or the Goop. Discard the rear of the car.
7. Using the file, knife, and sandpaper, smooth all cut plastic edges.

Launcher Modifications

The launcher consists of an orange box that contains the firing controller, a length of wire from the controller to alligator clips which attach to the ignitor wire and a string with a loop on it which is attached to the guide string. There is also a metal "blast shield" on the front of the launcher.

1. Remove the guide string from the above-mentioned loop. Make sure you save the metal double rings as they may be useful later.
2. From the bottom of the launcher, pull out the controller and the wire and untangle any tangles.
3. On top of the launcher is a purple, vented, access hatch. This is where the alligator clips are. Open the hatch. Underneath is a purple wire clamp/holder which is glued to the body of the launcher. Using a knife or screwdriver or similar, pry/push/break this clamp/holder loose. Feed the alligator clips through the resulting hole. Save the launcher box as it and the end tensioner/string reel mate together and make a handy case for the launch controller, parachute, extra rocket motors, etc.

Recap to this point

Alright, you now have all the pieces for the boat cut, hacked, pried, shaped, etc. We will begin assembly in the next section. First though, there are some other bits and parts not yet discussed with which you should know what to do:

Hull Assembly

1. Fill the grooves cut in Boat Modifications Step 9 with epoxy or Goop.
2. Insert metal axle in the grooves with the ends of the axle even with the outside edges of the hulls. Wipe up any excess adhesive.
3. Using a toothpick, spread a line of epoxy or Goop along the lines drawn in Boat Modifications Step 11.
4. Place wood brace cut in Boat Modifications Step 10 in the lines of adhesive.
5. Align the tops of the hulls to make them even.
6. Let adhesive dry.
7. After adhesive dries, paint and decorate hulls to taste.

Body Assembly

OK, this is where it gets a bit dodgy. You'll be gluing together things that were never meant to be mated or glued together, so pay attention. You don't want your boat disintigrating mid-run and sending bits and pieces flying into your crowd of spectators.

1. Modify the engine mount and mate to body:
   1. Turn the rocket engine mount upside down with the string guide and clips pointing up.
   2. Place the point at which the string guide pylon meets the round engine mount even with the top of the opening in the rear of the car body.
   3. Mark where the pylon meets the top of the headrest.
   4. Using a hacksaw, cut straight back at this mark about 1/4".
   5. Using a hacksaw, cut straight back on the line where the pylon meets the engine mount about 1/4".
   6. Using pliers, wiggle the resulting tab back and forth until it snaps.
   7. Dry-fit the engine mount in the body. The pylon should reach to the front of the headrest and the round engine mount should insert into the rear of the car body. If this is not the fit you have, make adjustments using the hacksaw or a utility knife.
   8. When you are satisfied with the dry-fit, place a blob of epoxy or Goop on top of the head rest, another line on the rear of the notch you cut in steps 4-6, a line along the bottom of the same notch and a blob in the bottom inside of the body.
   9. Carefully insert the engine mount in the car body and align the center axis of both pieces, keeping the string guide pylon vertical.
   10. Allow adhesive to dry.
2. Create and install the wing mount:
   1. Align the square of sheet aluminum so that it sits vertically on top of the clip protrusion on one of the engine mount clips. Mark where the top of the clip meets the aluminum.
   2. Lay the aluminum on a flat surface and place the ruler on the aluminum along the line drawn above.
   3. Bend the protruding aluminum up using the ruler to hold the sheet down. You should have an "L" when done.
   4. Lay the aluminum "L" on the clips and mark where the aluminum meets the outside of the opposite clip.
   5. Bend as before. When done you should have a squared-off "U".
   6. If the legs of the "U" are not equal, cut the unmeasured leg even with the measured one using tin snips.
   7. Test fit the aluminum on the clips. It should fit snugly but not too tightly.
   8. Using a toothpick run a line of epoxy or Goop along the top edges of the clips.
   9. Gently place the aluminum over the clips, aligning the front of the aluminum with the front of the clips. This is now your wing mount.
3. Install the wing:
   1. Using a toothpick, run a line of epoxy or Goop along the bottom of the wing pylon.
   2. Center the wing on the wing mount side-to-side and align its axis with the center axis of the body/engine mount assembly. Move it fore and aft to make sure the pylon sits flat on the wing mount. The front of the wing will be about 1/4" aft of the front of the string guide. Try to level the wing side-to-side unless you want your craft to do barrel-rolls (which is actually quite cool looking).
   3. Allow adhesive to dry.
4. Decorate the body assembly with decals and/or paint to taste.

Final Assembly

This is somewhat like mating the shuttle to its fuel tank and external rocket booster assembly. It's not too difficult but you should do some balance and weight distribution tests. This is all included in the following steps.

1. Place the hull assembly in a pan of water.
2. Install a rocket engine in the engine mount.
3. Gently place the body on the hull braces and center side-to-side.
4. Ideally, the entire craft should be balanced evenly fore to aft or very slightly bow-high. Move the body backward or forward to achieve this balance.
5. Mark, or take mental note of, where the body meets the front brace.
6. Remove the craft from the water.
7. Remove the body from the hull assembly.
8. Remove the rocket engine.
9. Using a toothpick, run a line of epoxy or Goop across the front brace.
10. Place a blob of epoxy or Goop in the middle of the rear brace.
11. Align the point of contact determined above with the front brace and place the body on it. Rotate the body until the motor mount settles into the blob of adhesive on the rear brace. Center the body side-to-side.
12. Wipe up any excess adhesive and allow to dry completely. We let ours dry overnight.