Sunward Aerospace Liberator

Sunward Aerospace - Liberator {Kit}

Contributed by Lance Alligood

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Sunward Aerospace

Brief:
KitThe Liberator is a complex jet fighter-like design single-stage low power rocket that's built (and weighs) like a tank. The manufacturer rates it as skill level 3.

Construction:
The kit contains:

  • 18in BT-56 body tube (slightly larger than BT-55)
  • Plastic nose cone with canopy bubble
  • Laser cut balsa wood fins
  • "Jet engine intake" wrap-around and fin reinforcement sheet
  • Decal sheet
  • Parachute plastic sheet (for 18" chute)
  • Self-closing plastic bag with launch lugs, motor tube, thrust ring, centering rings, shroud line, parachute reinforcement rings, and elastic shock cord.
  • Instruction manual

The good news: My first impression when opening the bag was that the parts appeared to be of great quality. I'd never built an LPR kit with laser cut fins and it's clear to see why they're all the rage. (In fact, this was my first non-Estes LPR.) The high quality of the balsa is worth noting as well. The nose cone was made (and had the weight of a scaled down version) from the same plastic used on mid and high power rockets. The canopy for the cockpit was part of the nose cone. When dry fitting the parts, the nose cone also fit snuggly--I can see why tubing slight larger than BT-55 is used. It simply would not fit in anything smaller. The instruction manual appeared to be very thorough. 7 pages (on 8.5"x11" paper) front and back showing 26 steps (not including giving the rocket a swing test, preparation, warrantee, and Canada's model rocket safety code). To be Canadian friendly, all steps were in English and French. This also was the first rocket I'd ever built where I had to assemble the parachute. The plastic for the chute is considerably thicker than any Estes chute I've ever seen.

The bad news: Dry fitting the motor mount found all parts to be rather loose fitting. Sliding the beefy (for an LPR) centering rings into the BT-56 was loose as well. All of this is noted in the instructions too. I didn't care for the way outer edges were defined on the cardstock template. Instead of thin, sharply defined lines to cut out, there are areas of gray shaded areas that define the parts not to be used. As carefully as I cut the pieces out, there was a slight inconsistency in part sizes (like for the "top" fin). Perhaps the most disappointing item was the shock cord. It was merely a piece of elastic. 30 inches of quarter-inch 100% stretchy rubber. No polyester. As determined as I was to build this kit entirely stock, the image of the nose cone and chute drifting off as the rest of the sustainer tube plummets to the earth when the shock cord burns through was something I just couldn't get out of my head. I chose to use 3ft of 1/4" elastic from my supply box.

Construction was guided well by the manual. First was the motor mount. Another item of note is that the MMT uses a small threaded L-shaped piece of metal in place of the bent metal clip for motor retention. Once assembled, you twist the end over or away from the MMT tube to hold or remove the motor, respectively. A different mousetrap, if you will.

Next was the body wrap. Cut from the cardstock, folded along marked lines, and initially tacked on to the body tube lengthwise. The instructions do a good job to recommend that enough time be given to let the glue dry after each step here. The wrap eventually goes around the entire tube with parts flared out to create the air intakes. Despite my careful marking of the tubes I managed to get the cardstock attached slightly crooked...but again, that was completely my own fault and wouldn't be enough to detract from the overall design and flight of The Liberator. Also I found that using a paperback book helped hold the cardstock in place while drying so that I could briefly attend to other matters. And I was hoping that the cardstock would "heal" somewhat when the glue dried. The paper used is a little sensitive to the moisture in white glue to the point of being visible and slightly raised to the touch. Hopefully primer and sanding will reduce or eliminate the glue lines.

The cardstock already has the markings on it as to where all the fins should be placed. There are 6 pieces of balsa that cover the bottom of the rocket and one fin on the top. The top fin has 2 other pieces of cardstock glued onto each side to aid in adhesion to the body tube. These extra flaps do add weight and in my opinion detract from the overall sleekness of the design but definitely gives extra rigidity to the fin and should prevent it from ever popping off on a hard impact. Also, running a bead of glue along where the fins come in contact with one another greatly increases rigidity and should eliminate any potential fin flutter.

The rest of the construction is routine...glue on the decorative pieces and launch lugs, glue in MMT, 3-fold shock cord mount, assemble parachute. Something that will surprise those concerned with the wing aerodynamics is that it's not till step 24 that you are recommended to round the wing edges. I didn't bother with doing that and left the wings as is but I can see where you might accidentally round an edge (or part of one) that shouldn't be... Still, I would think it much easier to sand the wings before they are glued onto the body tube.

Once assembled, I liked the plane-like look to it. The wings provide enough sustainable lift I, in fact, was able to get it to glide quite a ways when throwing it horizontally (across the room onto a nearby bed or sofa). This bird is heavy though. Even with the thick paint job on my stock Big Bertha, the naked Liberator feels noticeably heavier.

On construction alone, I think skill level 3 is pretty accurate considering the complexity of the cardstock body wrap. It's definitely a technique that you won't see in many kits.

On the padFinishing:
I didn't break out the Elmer's Fill 'n' Finish because I wanted to see how this high quality/density balsa directly reacted to Krylon primer. The body tube spirals are so light (especially when compared to the edge of the cardstock wrapped around the body tube), I didn't bother filling them in either. Once primed, there's a lot of area to sand for an LPR but it didn't take very long due to the quality materials. Care needs to be taken on the body wrap so as to not cause any unwanted dents or creases. Also, the nose cone is made of high-density polyethylene, which is an unusual material for an LPR. Take it from someone who has built MPRs & LPRs: rinse the nose cone and then sand it with 250 or 320 grit sandpaper before you even think about putting on any paint. Otherwise the paint will peel right off the waxy surface. A couple of coats of primer and she was ready for final gloss coats.

I liked the paint scheme on the packaging insert over the camouflage scheme shown on the website, but used gloss black instead of red to accent against the silver underside. I'm pretty pleased with the results. There are self-adhesive decals--lots of them--and the kind that you also have to cut out individually too. Sunward Aerospace is a Canadian company but they're nice enough to recognize the customer base in the US and UK. Included is a nice choice of flags, logos, and symbols to represent all 3 countries equally. The decals provide an excellent finishing touch to the rocket. Lastly, I put an accent stripe around the canopy bubble (since the canopy and nosecone had both been painted black) with a new Sharpie metallic silver marker. I hope these pens become available in more colors...they offer a paint-like quality but with the fine detail and application of a marker. Excellent for detail work.

And like I mentioned above, The Liberator is HEAVY. Finished weight (sans motor) is 4.5oz! I knew early on that this rocket was going to be underpowered--even on a C6--based on weight alone. I don't have access to one but my gut tells me that the only way this bird is going to achieve decent altitudes is for those brave souls with an AT D21. Let see how she flies...

Construction Rating: 4 out of 5

Flight:
First flight recommendation is a B6-2. Uh, I don't think so. Seeing how my Big Bertha flies best on a C6-3 and weighs a full ounce LESS, I'm not putting The Liberator up on anything else the first time out. I felt the shorter delay would be a good idea, again, due to the weight.

I prepped it with a few pieces of wadding, readied the motor and put it up on the pad. It was breezy day but I still aimed the rod straight up. The Liberator had a slow but straight liftoff to maybe 300ft before the wind pushed it over into an upside down position (the belly of the plane facing the sun) where it ejected at apogee. I apparently didn't put in enough wadding as all but 2 of the shroud lines burned through. The body tube stayed horizontal the whole way down so the broad wings and the little drag provided by the chute allowed it to still land safely without damage.

Taking to the skyThe wind had calmed slightly right before the second flight (on the same day). I borrowed an 18in Estes chute (with a 2in spill hole) from my Fat Boy and put in a couple more pieces of wadding--I think I used 5 squares--than last time. I also tried to put The Liberator on the pad so that any wind would blow across the fins instead of pushing the bottom of the rocket like a sail, as was the case on its maiden voyage. This proved to work quite well as I'd say the second flight peaked closer to 450ft (but still well short of the manufacturer's claimed 600ft). Ejection was right at apogee, only the chute came out but didn't open. The body tube again remained parallel to the ground during the entire descent until it landed on the soft, grassy field. Post-flight analysis revealed a couple of scratches, a slightly dented decorative fin tube, an Estes-style dent in the body tube from the nose cone, and a poorly packed chute. User error was the cause of poor recovery this time.

I waited to have the third flight on a calmer day. Well, at least on the ground anyway. I discovered there were some gentle high winds that The Liberator got caught up in but not till it boosted nicely to ~400ft. The nose just started to rotate downward as the chute deployed perfectly this time. I was using an Estes 18in chute with a 2in spill hole cut in it so it descended quickly, touching down 200ft from the pad. Finally a completely successful flight! My advice: only fly this rocket on calm days.

I didn't try The Liberator with a longer delay than the C6-3. I bet with the couple extra seconds in a C6-5, you might be able to get a brief glide (as my pre-finishing tests showed) before ejection. (I even wonder if it's possible to get this design to have a complete glide recovery...?)

Recovery:
I obviously had a couple of serious recovery problems with The Liberator, both of which can be traced back to operator error. However, given a calm day and when nothing goes wrong, it recovers reasonably well if not a little fast. For an LPR it does descend quickly, even on an 18in chute, so it shouldn't drift much for those folks flying this rocket on a small field.

I plan to repair the kit chute with Kevlar® shroud lines as the plastic is a significantly higher grade than what comes with an Estes kit.

Flight Rating: 4 out of 5

Summary:
This is a very attractive and durable kit but I'd have to say that I'm not sure if I'd fly it as regularly as other kits in my fleet, mostly because of the risky recovery. Anyone who is big into military/scale kits and/or someone looking for a new challenge in LPR building might find The Liberator a welcome addition to their fleet. It's a real shame that this kit is limited to only 18mm motors. With the rugged construction and high quality parts, this rocket should be able to handle the motor mount and thrust of at least a 24mm Estes D12... I mean it looks like a jet, so why not have it take to the skies like a jet!

Overall Rating: 4 out of 5

Flights

Comments:

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K.G. (September 18, 2003)
I'm getting ready to start a Liberator kit, and appreciated the review. Since it is a heavy kit with a quick descent rate, what about using a smaller chute (e.g. 12" wspill hole?) for the nose cone and the 18" kit chute for the body? There's plenty of room in the large BT, and it should also eliminate the "Estes Dent" the reviewer noted on one of the flights. No pun intended, but is there any down side . . . ?
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C.A.M. (August 20, 2004)
Nice review. I plan to buy a couple of these. I loved the Centuri jet-like rockets from years ago, and now SUnward has two that I want, the Liberator being one. In looking at it I think it looks just like the Northrop F-20 Tigershark which is how I hope to decorate mine. It also looks like the earlier F-5 Freedom Fighter except for the single engine outlet. I have the same flying issue with my Centuri F-4 Phantom jet rocket. It always pulls itself over on its back and flies horizontally for the last third of the flight (if not more). In doing some research I believe it need more weight in the nose. Like the Liberator, it is a heavy rocket for its size.

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