Rogue Aerospace Crossfire

Rogue Aerospace - Crossfire {Kit}

Contributed by Moira Jean Whitlock

Construction Rating: starstarstarstar_borderstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstar_borderstar_border
Manufacturer: Rogue Aerospace
[Picture] (06/01/98) Rogue Aerospace's Crossfire is a unique two-stage kit that uses B and C motors. It's another eye-catcher for it's unique booster design. It is rated as a Skill Level 2 and is 20" long, 1" wide and weighs in at 1. 4 ounces (my completed model weighs 2 ounces).

The kit comes with a single sustainer body tube and a short booster body tube. The motor mounts come with the centering/mounting rings and motor hooks for both the sustainer and the booster. There is a vacuum-formed plastic nose cone, a 12" nylon parachute, a Kevlar® tether and a piece of Perma-Wadding. For the fins, there are two balsa sheets, a 3/32" and a 1/16", and templates to cut out the four fins for each section. Also, there is 4. 6" x 1" outer booster fin ring, which gives this kit it's unique look. Lastly there is a set of water transfer decals with a large gold Crossfire decal and various others. [Picture]

CONSTRUCTION:

There are eight pages of clear instructions. Not a lot of illustrations, however, the ones provided give important information, such as motor mount assembly, template placement on the balsa sheets, grain alignment when mounting fins and the assembled booster stage with the fin ring. The instructions are in logical order, however, I would suggest reading all of the sub-steps for each main-step and review the illustrations before starting. This will help avoid questions and problems.   For example in step 1-e you are told to "slide the notched centering ring on from the front of the tube until it is even with the mark". The "front" of the tube is marked in the bottom illustration. This is very minor considering that most modelers understand that the front of the rocket is the top, as opposed to the rear (bottom).

The assembly of the Crossfire was straight forward and did not pose any major problems. All of the parts fit correctly. I was impressed to see that the pattern placement and attachment step for the fins ensured that the balsa grain was along the top leading edge. This will provide the most strength. Be very careful with the 1/16" balsa for the sustainer fins . . . this is some flimsy stuff until it is sealed with CA or primer. And even though the instructions call it optional, I tampered the leading and trailing edges of each fin. Just be careful with the thin balsa. Just be careful with the thin balsa. I broke the fin along the grain and had to glue back on with CA while finishing.

Another area to take care on, is the installation of the sustainer's motor mount. Do your very best to keep glue off of the lower section of the tube. This is where the booster slides into and can cause problems with fit if there is glue there.

The unique part of the Crossfire is the booster fin ring. My ring fit perfectly and didn't require any additional sanding of the fins for fit. The only precaution is that the fin ring, if snug, can cause the fins to come out of alignment, so take care to ensure the fins are still straight before the glue sets on the fin ring. [Picture]

Assembly of the nose cone was unique to me, too. You drill (with a hobby knife) a small hole in the shoulder to allow the Kevlar® tether to pass through. This is tied to a retainer (small bead) which prevents it from passing back through the hole. Then the shoulder is glued onto the nose cone. With respect to the shoulder, I think it is a bit too short. It also required tape to make it fit snug into the body tube.

As always I start my finishing process with Plasti-Kote primer. I painted it gloss black and topped the nose cone with gold. I also did just the outside of the booster's fin ring in gold. This turned out very nice and matched the Crossfire decal. With regards to the decals, they are water transferable and along with the Crossfire name, there are 3 sets of Rogue Aerospace, 2 sets of numbers and 4 cross-hairs.

For CONSTRUCTION, I would rate this kit 4 1/2 points.

FLIGHT/RECOVERY:

The Crossfire is not your standard two-stage kit. The two motors are not taped together. Each motor mount has its own motor clip to hold the motors in. When assemble the motors are at a minimal distance apart to allow the in-flight ignition of the sustainer motor.

The maiden voyage was set up using a B6-0 in the booster and a B6-4 in the sustainer. The recommended motor for the sustainer is a B6-6, but I didn't have any. With everything set, the count down began . . . 3, 2, 1!

Ignition took place but the rocket didn't move, then the booster motor stopped just as the sustainer ignited. The sustainer took off quickly. We were able to seen the ejection and the 12" orange parachute deploy. Then what looked like a straight drop recovery started to turn into a drift and run as fast and as far as possible. This rocket was carried about 1/4 mile away . . . but was recovered!

After checking why the booster never lifted off, it was determined that the motor hook got caught on a "rod-stop" preventing it from lifting off. Not only that, but it burned a hole right through my blast shield.

[Picture]For the second flight, I ensured the booster was not hooked and cut a 2" spill-hole in the parachute. I used the same motors (B6/B6) and off it went. Perfect lift, visible separation and successful sustainer ignition. Out of site, trial of smoke, then a little orange parachute appeared. It was so high, I had time to pick up the booster and then start walking to where the sustainer landed. Watching the descend rate indicated that I could probably go with a 3" spill hole or tighten up on the shroud lines. This kit is a good candidate for a streamer, because I can only imagine the altitude with C6/C6 combination.

Booster is not only unique looking, but also unique in it's descent. I spins making it look like a sphere!

I just want to mention this kit's recovery system. It uses a Kevlar® tether as already mentioned, which is attached to the thrust ring for strength. Rogue Aerospace's also provides a nylon parachute and a piece of Perma-Waddingwhich eliminates the need for wadding paper. I love this stuff and have purchased it separately from Rogue for my other kits.

For FLIGHT/RECOVERY, I would rate this kit 4 points.

Overall, for the uniqueness of the fin-ring, quality of a rip-stop parachute and Perma-Wadding™, the Crossfire is a great kit for someone looking for a two-stage kit. I give the kit an OVERALL rating of 4 1/2 points.


- by Moira Jean Whitlock

[Rocket Pic]Brief:  This is a 2-staged 18mm, 4-finned rocket with a ring around the fins of the lower stage.

Construction:Everything was there and in good shape, not warped. The nose cone is hollow plastic, the body is spiral wound paper, the fins are die cut balsa at 1/8 inch thickness. The instructions were logical and straightforward with some pictures. However, the nose cone came in two parts, that is, the top and bottom, and needed to be glued together. And the lower stage alignment with the ring was a bear. I had to sand the chord edges of the fins until the ring could fit without either distorting the body tube or skewing the angle of fin attachment. In other words, the fit was too tight. In other words, the fit was too tight. But once I got it to fit, it looked great. Do be warned that it will take some doing, though. It took me two days to get it right.  Built up, the model is now sturdy and sharp looking.

Finishing:There weren't any decals, so I finished the model by making the fins, inside of the fin ring, and nose all black with Testor's enamel paint. The body was finished with metallic flake adhesive-on-one-side greeting card paper. This can be bought at craft stores such as Michael's. The outside of the fin ring was finished with bands of the adhesive glitter paper too.
The nose cone was a tiny bit too loose, so I supplied a thin band of masking tape to the nose cone shoulder to tighten the fit.

Construction Rating: 3 out of 5

Flight:The recommended engines are: The recommended engines are: B6-0 or C6-0 for the booster and B6-6 or C6-7 for the sustainer. I used these thus far, and plan to try some engines from Apogee later. I have made some motor adapters so the sustainer can use their 10.5mm B7-8 engines.  The booster is too short to use the B7-0, though. I used my usual worm bedding wadding, just enough to fill the diameter of the body tube to about half an inch. The engines were retained with a motor block in the sustainer with a tape band around the aft end of the sustainer's motor, and tape for the aft end of the booster's engine. No actual method was provided otherwise with the kit itself. The model flies straight and nicely. And the orange chute supplied looked great.  I wish the booster had its own recovery system instead of tumble recovery, though.

Recovery:The shock cord I modified.  The kit came with a 36 inch length of 1/16 inch thick Kevlar® cording. That's fine as a rule, but one of my hangups with shock cords is that the should stretch to reduce stress on the shock system. So, I added a 2-foot length of flat, 1/4 inch elastic to the forward end of the cording.  The kit supplied a plastic bead to retain the shock cording from inside the nose cone. The knot is made inside the nose cone before its two halves are assembled. The rocket so far has suffered no wear or damage, except some slight scorching of the booster, which seems common in contact staging. The parachute is thin orange nylon, 10 inches in diameter.  Although it's a flat hexagon, it inflated nicely. It seems just right in size, as the rocket descends softly.

Flight Rating: 4 out of 5

Summary:Cool looking, flies straight, catchy fin ring draws attention. Any cons include alignment of the booster taking some determination, but the result is worth it. The shock cord wasn't stretchy. Maybe it isn't necessary, but I added elastic to it for stretch. If I'd change anything major, it'd be to supply the booster with a recovery streamer. This would help in making it visible for recovery while the flyer concentrates on locating the sustainer.  But so far I finished the fin ring with bright glitter paper for visibility.

Overall Rating: 3 ½ out of 5



[NAR][Sport Rocketry]

The following excerpt is from "Sport Rocketry". The intention is to allow guests to get a basic feeling about a kit. We strongly suggest that you get a copy of the referenced Sport Rocketry and read the entire article. Inside you will find many helpful hints in construction as well as other useful information. For more information, use the two links above.




(Sport Rocketry - Sep/Oct 1998 - page 31 - by Greg Elder) 

"If you find building rockets to be as much fun as flying them, then you should enjoy the kits offered by Rogue Aerospace."
"The Crossfire is a two-stage rocket which has a ring fin on the booster."
"This kit features a vacuum-formed plastic nose cone, balsa fins, a Kevlar® shock cord, water transfer decals, a 12" diameter nylon parachute, and perma-wadding."
"Eight pages of easy to read, illustrated instructions . . ."
"I found the Crossfire fairly easy to build."
"For the fins, you are provided with templates to trace on the supplied balsa stock."
"I flew my Crossfire with a B6-0/B6-6 combination."
". . . straight flight and staging was very smooth."
". . . returned the sustainer without a scratch."
"Overall, I think the Crossfire is a great kit."

The entire article gives the impression is that this unique looking 2-stage kit for an intermediate modeler.

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