The Nordic Rocketry Incorporated DELTA-X was my first rocket from this company, and I was pleasantly surprised with the quality of it. This is a good rocket if you're ready to jump from regular black powder motors to D composite power.

INSTRUCTIONS:

The instructions were clearly numbered, illustrated and easy to follow. This is not a regular model rocket, you need epoxy or a similar glue to build it. I would not recommend building this rocket with white glue.

EASE OF BUILD:

This rocket is rated Skill Level 3 on the package, but is surprisingly easy to build. All the parts were in my kit, and fit was good. Some sanding was necessary for the shoulder of the nose cone to get it to fit into the body tube, and sanding of the motor mount rings was necessary to get them to fit on the motor mount tube and in the body tube. Also check the motor mount tube with a motor to make sure it fits, some sanding may be required.

TEST FIT ALL PARTS BEFORE GLUING. As the instructions say, you do not want to find out the parts don't fit when your epoxy is "setting up".

Alignment was a bit tricky with the X-design fins.   An easy-to-use fin template is included, but a cardboard cut-out fin jig would have helped get the proper angle for the fins. After getting out the ruler and propping up the fins, this worked out okay. If the x-fin design totally freaks you out, you can always put the fins on in the typical 4-fin pattern found on most rockets.

This rocket uses a novel shock cord attachment method.   Instead of the usual anchor, it uses a screw eye in the forward motor mount ring. This makes for a very strong attachment, but also could cause catastrophic failure if ejection pulls the motor mount out of the rocket.   I filleted the motor mount rings and made sure they were solidly glued into the body tube.

If your shock cord does come loose while flying, putting it back on the screw eye will be very difficult if not impossible.   I plan to use a typical three-fold cardboard anchor if this happens to me.

QUALITY:

The first thing you notice when you open this kit is that it is not an ordinary cardboard-and-balsa model rocket. No cheap plastic chute here, a sturdy 14" nylon chute is included. The fins and motor mount centering rings are sturdy 1/16" plywood. The launch lugs are brass.   The body tube has thicker walls than the ordinary model rocket tube. This rocket is obviously built to take the extra stress of composite motors.

The rocket comes with a rub-on DELTA-X decal, which was a problem. The decal rubbed on fine, but when I peeled off the top layer, it took off the paint job with it! This is a definite problem that needs to be worked out. I tried to keep the sticky stuff off the rocket when applying the decal, just like the directions said.   This is next to impossible, it likes to stick to the rocket. It is like holding a piece of scotch tape right next to a piece of paper, they have almost a magnetic attraction. The top layer should not have any adhesive on it, only the decal letters should stick.

I decided to paint mine in a fluorescent orange color to match the parachute. (Use a white primer coat under fluorescent colors) I touched up the parts where the paint peeled off and it looked okay.

This rocket isn't anything special in looks (I tend towards military scale models) but isn't the usual 3FNC (three-fins-and-a-nose-cone) either. The X-fin design makes the rocket look a bit more exotic than usual.

CONSTRUCTION RATING: 3 points

FLYING:

This rocket flew well on an Estes C6-3 for the first flight, and an Aerotech D21-4 on my second flight. The launches and recoveries both were flawless, even with the notorious Aerotech "copperhead" igniter, which has a well-known tendency to misfire.

Performance was impressive. I didn't get altitude readings, but the rocket went almost out of sight and the crowd of experienced rocketeers was impressed.

Problems surfaced after the second flight because of the tight motor mount tube. Although I was able to remove the C6-3 with pliers, the D21 motor broke into pieces and removal had to be done back at the workshop. The problem may not be with the tube but with the inner diameter of the motor mount ring. I could not insert the motor mount tube into the rings when I first tried, I had to sand the inner diameter to get them to fit. It may have still been a tight fit and compressed the tube so the motors were a tight fit. This is a definite problem, and you should test-fit this rocket with all engines you plan to use, sanding the inside of the motor mount tube as necessary to ensure a smooth fit.  

Although Aerotech D's pack a lot of punch for a small motor, they do it for a steep price. The D21 single-use motor retails for $7. 95 which is almost three times the price of Estes D12 motors, which have respectable power. (The Estes D12 motors sell for $8. 79 a three pack)  Long-term users can purchase a 18mm reload case and then get D13 or D24 reloads for $8. 95 a three pack, but the Aerotech 18mm motor case is a hefty $39. 95 retail. I prefer Estes "D" motors because of this cost advantage and the igniters are more reliable.

So, the concept of a rocket which can be used to step up to D power sounds like a good one until you look at the price. I think a a rocket with a 24mm motor mount and a 18mm adapter would serve this purpose for less cost to the user.

FLYING/RECOVERY RATING: 4 points

OVER ALL RATING:

I give this rocket 3 ½ points. It is a very sturdy and well-designed rocket for 18mm composite motors. The X-shape fins give it an exotic look. I'm looking forward to seeing what other surprises Nordic Rocketry has in store for us.