My favorite movie has always been The Wizard of Oz. With that in mind I decided to build a rocket that could carry several passengers over the rainbow. The nice thing about building Dorothy from the Estes Loadstar kits is that you already have most of the materials and you will have spare fins and chutes left over.
While there are many steps to assembling the Loadstars individually, there are 7 main steps to building Dorothy from them. I would say Dorothy is a level 4 build but anyone with average building experience can be successful.
Read this through before starting the project and refer to photos often.
*Allow glue to dry between steps and refer to the photos to help understand the following:
1. Construct the two outboard body tubes and two boosters, per Estes instructions but leave one fin off of each one.
2. Construct the core body tube and booster per Estes instructions. It will consist of the engine mount, no fins.
3. Make 6, 1" x 1/2" x 1/4" shims from scrap balsa. Place 1 shim flush with each end of both outboards and place 1 in the middle between the body tubes, to act as standoffs, then mate all 3 body tubes using the shims. Make sure the tubes are equal on all sides. When dry, attach the 1/8" x 3" x 9" balsa sheets to both sides. The sheets should be flush with the bt's at both ends and in the center of the outboard tubes.
4. Permanently install the bt coupler to the core body tube and the last Loadstar body tube. This will make the core body tube 18" long without the payload section. Install 1, 24" 'chute and attach the payload section to the opposite end.
5. Permanently attach a payload section to each of the outboards using #6 1/2" screws.
6. Paint and decal as desired.
7. Make two standoffs the same as in step 3, 1/2" x 1/2" x 1" and attach launch lugs. Center the lugs at the top and bottom of balsa sheets on the same side.
Dorothy will fly as a three engine cluster or a three to three, six engine staged cluster.
Three engine cluster options: Outboards: B6-0 & Core: B6-4 or Outboards: 2 x B6-0 & Core C6-5.
Three stage cluster options: First stage: 3 x C6-0 2nd stage: Outboards: 2 x C6-0 & Core: C6-5.
Dorothy has made three excellent flights as of 11-1-2005. The first two flights were as a single stage, flying on two C6-0 and a core C6-5. Both were excellent and we only cracked a fin when the wind caused a hard landing on the second flight but it was easily repaired.
Our first attempt of a two stage flight was on three C6-0s to two B6-0s and a core B6-4 cluster. Weighing in at 19.5 ounces when fully prepped, Dorothy is a little heavy for three C6-0s but she is very stable. Estes rates the maximum lifting capabilities of a C6 at 4 ounces, Three C6s shouldn't be able to lift Dorothy off the pad but they do and quite well.
Prepped and ready to go, the button is pushed and all three engines lift her straight up. Despite the weight that the three C6-0s are lifting, the Scare Crow, Tin Man and Lion easily clear the pad. They reach 150' and the second phase of the flight while climbing at a pretty good clip. Without delay the chad staging pops off the first stage boosters as the second stage engines ignite. Again all three engines of the second stage power up together as Dorothy shifts into second and picks up a nice kick. A slight angle develops as she continues to climb rapidly and tops out about 800'.
Dorothy coasts for a few seconds then finally the chute ejects at about 500', but doesn't fully deploy because the ejection has partially fused the plastic chute together. At best, deployment is about 50% and the rocket goes into a slow flat spin which actually helps to slow the descent. The field grass is deep and she lands without any damage. Be sure to use a mylar chute!