Background

The Eliminator is NCR's highest flying rocket. It gains a lot of altitude for its size, making it one of the most popular mid power rockets in the model rocketry world. The rocket itself has been made by North Coast Rocketry for many years. However, the design was improved and new features were added when North Coast Rocketry was bought by Estes. And with Estes' powerful marketing, it has become a very well known rocket.

Construction

Depending on what you want out of the rocket, it can be built one of two ways. You can always build it exactly like the instructions tell you. However, there is a slight difference in motor selection with this rocket. The original design is for North Coast F62 and G70 Dark Star motors. However, all Dark Star motors are single use, and therefore, are very expensive. If you want to use the cheaper AeroTech RMS motors, the rocket will need some modifications.

First of all, NONE of the AeroTech motors will fit inside of any of the North Coast rockets. Obviously, they want to make sure they sell a lot of Dark Star motors with their rockets. But not very many people I know have trees in their back yard that grow the money needed for the $12/flight needed for the Dark Star motors.

If you wish to use AeroTech motors, you will need to replace the motor tube that comes in the kit with a LOC/Precision 29 millimeter motor tube. The LOC 29 millimeter motor mount tubing is sold in lengths of at least 76 centimeters. You'll need to cut it down to a tube the proper length for the rocket. Then, follow the instructions for putting together the motor mount. But remember that you will need to sand the inside diameter of the centering rings in order to get them to properly fit onto the 29 millimeter motor tube.

In addition, a red retainer ring is supplied in the kit. This will not work with AeroTech motors. It will not fit over the rear gold closure of the AeroTech reload motors. Instead, you will have to use a retainer of your choice. I have information on a common retainer which I used for my Eliminator in the segment Motor Retention.

I also recommend installing a LOC Modular Baffle Unit. Wadding isn't very reliable with larger diameter rockets, at least the North Coast wadding isn't.

The six decimeter parachute that comes in the kit is a little too small. I would recommend using a seven decimeter parachute.

Other than the modifications for AeroTech motors, the quality of the kit is very high. It features T3 fin attachment for extra strength, strong plastic centering rings, and an excellent shock cord mount. I recommend having a crimping tool handy for when you install the shock cord mount. The shock cord mount is a steel cable which connects via loop to the forward centering ring of the motor mount. Then., a loop is made on the other end of the cable toward the front of the rocket, which is where you tie your shock cord to. The loops are held together with metal sleeve connectors. The sleeve connectors slide onto the cable at the bottom of the loops, and then crimped to be held in place. This is a very strong and reliable method of mounting the shock cord, and the entire recovery system.

When assembling the motor mount, its easy to get confused. Go over the instructions several times before you glue the motor mount together. It especially gets confusing when you glue the motor mount inside of the rocket. The instructions say to put a band of epoxy inside of the body tube at the front of the fin slots and then feed the shock cord through the tube and slide the motor mount in. This isn't the proper way to install a motor mount that has a shock cord attached to it because you are too likely to get epoxy on the shock cord, which will weaken it. What I suggest is, do not tie on the shock cord after you put the steel cable shock cord mount on the motor mount. Its pretty easy to avoid getting epoxy on the steel cable since it is stiff and doesn't move all over the place inside of the body tube. If a little bit of epoxy gets on it, it shouldn't affect it since it is steel. The loop of the steel cable where the shock cord attaches will be near the front end of the body tube. You will be able to tie the shock cord on easily.

Remember also that the fins will attach to notches in the centering rings. When you glue the motor mount in, make sure that the notches are aligned with the fin slots, and test fit the fins while the epoxy is setting to ensure proper alignment.

The constant warping of the birch plywood fins drove me nuts. Take a look at your fins, and if they're very warped, boil some water on the stove. Hold each fin in the steam making sure that all areas of the fin are being steamed. Steam the fins for a minute, and then stack them under heavy books for a day or two. This won't get them totally flat, but it will get them flat enough so that they won't make the rocket unstable or squirrelly. The only thing that the rocket could possibly do in flight is roll, but rolling can add stability.

Flight

The Eliminator is an outstanding flyer. The Eliminator is a very stable rocket that can reach altitudes up to nearly 457.2 meters. It flies well on F62 Dark Star motors, but is spectacular to watch on AeroTech G33 Black Jack and G64 White Lightning motors. It refuses to weathercock, and its lift offs are slow and realistic.

Grades

Design: A 
Construction: C 
Flight: A+ 

As you can tell, construction isn't very easy. This rocket is a good one if you're tired of the same old AeroTech and LOC rockets every time, but like all mid power rockets, it is not recommended for beginners. I also do not recommend it as a first mid power rocket. I only recommend it if you have at least a year of experience with mid power rockets.

Note: For more Eliminator pictures, visit Dave's site.

The Eliminator kit is a kit I highly recommend. It has the Estes glossy design packaging and the design of the rocket is sleek and easy to build. This is a good kit to start out with and will get on you on the way to high power in good kit design. The only problem with this kit is the slightly smaller engine tube. It is designed for North Coast Rocketry's 'Dark Star' engines, but will except a 29mm reloadable casing. Anyway, if you are going into high power you will save money by using reloadables in the first place. Because of the motor tube difference I give this kit a 90% rating. It would get a 100% if it had a 29mm tube instead of 28.987mm. I think this was done so Estes would be sure of the success of their "Dark Star' engines. However the 'Dark Star' engines are excellent motors, the only problem the 'G' motors are not yet available. Well, look at the pictures and see this rocket in flight with the 'Dark Star' F62-6 motor, they do have an impressive black smoke trial.

The Eliminator Kit

The 'Eliminator' in Flight

Brief:
This is a simple 3 fin and a nose cone rocket. It is straight forward and easy to build. It would make a fairly good first mid-power rocket.

Construction:
Upon opening the box everything looked to be in good shape, but when I laid the plywood fins down on a table, I noticed that they were warped. So they were put under a few hundred pounds of pellet bags for a few days and they came out nearly perfect. The body tube was a 'normal' tube for mid-power rockets, just cardboard. It had a bright red 24" chute with it too. When building your own, I would recommend putting some LOC 29mm motor tubing in the kit to replace the NCR one, since you can use Aerotech reload and single use motors. The instructions were easy to follow, fairly well written. In some parts you might have to read them over a few times. Building was extremely easy since there were no hard parts to building this rocket. I used 5 and 30 minute epoxy through out construction. Also you will want to put some t-nuts in the aft centering ring since the NCR gorilla retainer will not work on any Aerotech reloads or and Kosdon motors. One bad point to the rocket was the 1/8", 3-ply plywood fins. Since there are only 3 plys, it makes the fins very weak. I think that they need to be glassed. Some 2 ounce fiberglass cloth will work fin. I learned my lesson, read on to find out how. Just a note, most other mid-power kit manufactures use 1/8", 5-ply plywood for their fins, which make them much sturdier! One other thing is, it is very important to get the centering rings lined up, if you don't then your fins will not fit into the slots in the body tube.

Finishing:
Finishing was VERY easy! I just gave it 2 coats of primer and painted it as they showed on the box with Krylon gloss white spray paint and Krylon True Blue spray paint. The decals were nice, I would recommend getting some water and a little soap in a dish to put them on since it makes them much easier to put on as you can move them around.

Construction Rating: 3 ½ out of 5

Flight:
For my first flight I choose the 120 newton second Kosdon G40-7 c-slot motor. I just put some fiberglass insulation in and packed the chute, then put the motor in and put the retaining washer on and it was ready. On ignition the Kosdon G40 came to life and it went up nice a straight! The G40 is a very LOUD motor, especially for a G motor. The 24" chute came right out at apogee. But on landing it broke a fin due to the weak 3 ply ply-wood. This was a easy fix. I have put a 28" chute in it and have since then flown it on a Aerotech G35-4 for a really nice boost, but the delay was a little short. Rocket landed safely under a 28" chute.

Recovery:
The shock cord was 10' of 1/2" flat elastic, this was attached to the rocket by a steel cable that went through a centering ring, this is very strong. For the first flight I used a 24" chute, which was too small and resulted in a broken fin, for the next flight I used a 28" chute which was just fine.

Flight Rating: 4 ½ out of 5

Summary:
The Eliminator overall is a great rocket. The only down side to the rocket is the 3-ply plywood fins and the 24" chute. IF it was not for that, then it would have gotten a 5 over all.

Overall Rating: 4 out of 5