(Contributed - by Les Bradshaw - 02/16/08)
Probably no legendary sea monster was as horrifying as the Kraken. According to stories, this huge, many armed
creature could reach as high as the top of a sailing ship's main mast. Well, this rocket may not have many arms, but it
will fly higher than a ship's main mast!
This is my first kit from Pemberton Technologies, but it won't be my last. They even supplied RockSim files, that
they graciously allowed me to include with this review.
The Kraken is a single stage . I felt what made it unique was how the tube fins were pointed.
The rocket came with 2 BT-60 body tubes, one of which will be cut up into the tube fins, a 24mm motor tube with 2
centering rings, a balsa wood nose cone with a screw eye and a washer for weight, two 1/4" launch lugs, 60"
cord, and an 18" plastic parachute. There is a little piece of balsa wood for the canards. It also came with one
of the most amusing set of instructions (or destructions as they call it) that added to the fun of building this kit.
The Kraken comes with 19 pages of destructions including a photo quality picture of the Kraken. The most difficult
part of this rocket is cutting the tube fins. Nine of the destruction pages provide instructions, photos, drawings,
cave sketches, etc. to help you mark and cut the one tube into 4 tube fins. With all the information presented, making
the tube fins really is not that difficult. Make sure you use a sharp knife and take your time. You mark a line along
the length of the tube on the top and bottom. Marks are made at different positions and you need to draw lines between
the appropriate top and bottom marks. This creates the unique pointed tube fins.
There is a pattern for cutting the canards. I decided to round the edges of the canards. These glue onto the
balsa nose cone. I used thick CA to bond the canards since I was using thin CA to seal the balsa nose cone.
Next is the motor mount. Glue on the 2 centering rings. You carve a notch in the top one, tie the Kevlar
cord around the motor tube and pass the cord through the notch. Then glue the motor mount into the body. Notice I
didn't mention anything about a thrust ring or motor retainer? Well, there are no such things for this kit. The
destructions warn you to avoid pitchforks, torches, and mob mentality, and simply use masking tape or duct tape to
create a thrust ring on the motor itself. To hold the motor in place, the instructions say to wrap a bit of tape
between the motor tube and this thrust ring you created.
I finished my rocket before I glued the tube fins on. This makes it easier to get complete paint coverage. When I
did glue the tube fins on, I opted to use 12 minute epoxy since I would not be able to fillet the joints with the
The nose weight is a fender washer. This gets glued to the nose cone and a screw eye goes into the nose cone. The
cord ties to the screw eye. Unlike most folks who hate elastic, I added some in parallel to the Kevlar
to absorb some of the ejection shock.
The biggest issue with finishing a tube fin rocket is getting paint under the tubes. The method I used was to mask
off a glue strip with masking tape and then paint the pieces before gluing them together. I first filled the tube
spirals with Elmer's Wood Filler and sanded with different grades of sandpaper down to 320 grit, making sure to get
inside the tube fins. The inside of the tube fins were primed and sanded with 400 grit then painted with gloss red. I
used Krylon for all my painting. After the paint was dry, I masked the inside of the tube. I then used some 1"
wide tape that I cut down into 1/4" strips to create the glue strips. I beveled the top and bottom to match the
tube fins, but I also made the strips about 1/4" short to make sure I would not leave a gap. I then primed and
painted the outside of the tube fins and the body gloss black. I used multiple coats of thin CA to seal the balsa nose
cone and sanded down with 400 grit. The nose cone was also painted gloss black. As a finishing touch, I used a Testor's
Gloss Yellow Enamel Paint Marker and rimmed the tube fins. I also used the marker to paint the canards and followed
that with a red paint marker to make some eyes for this evil beast.
out of 5
The recommended motors range from an Estes C11 to AeroTech's E15. I went to my favorite local field where it was 24
degrees with a light covering of snow. I prepared some masking tape to use as the thrust ring in the comfort of my warm
house before I left. I used my Estes E size pad with it's 6' x 1/4" rod. I set up in the middle of the field and
prepped a D12-3. I tried the method of using tape around the motor mount and engine to secure the motor that was
suggested by the destructions. Some dog barf and parachute (I cheated here and used an existing 18" Estes chute I
have on a snap )in the other end. An igniter into the motor, onto the launch pad, and a countdown from 5. The
rocket left the launch pad for a beautiful straight flight.
Right before apogee, the ejection charge went off. The engine came out one end, but fortunately the nose cone and
parachute came out the other end. The parachute did not open, but the drag from the closed parachute and the separate
pieces still had the rocket coming down somewhat slowly. Finally, about 20' above the ground the parachute finally
opened. The rocket landed standing up in the snow without any damage. For the second and third flights, I changed to
friction fitting the motors. I also put the parachute in my pocket while I was prepping everything so it would be less
stiff. My second flight was also a D12-3. Again, a perfectly straight launch and this time the engine stayed in and the
parachute opened right away. And then it took a long time to land with a little longer walk to recover it. I was
thinking of trying an E11, but the wind started picking up so I used a D12-3 for the third flight as well. Again a nice
straight launch. But with the stronger wind, the rocket drifted away some. I think an 18" chute is a tad too big
for this rocket. I didn't try a fourth flight--my toes were freezing, but I would be tempted to try a 12" or
14" chute instead of the 18" chute supplied with the kit.
out of 5
This is a fun rocket with its unique tube fins. The rocket goes together simply (after you cut the fins). Due to the
fins, I would rate this rocket construction complexity as a 3. The quality parts and amusing destructions made the
construction enjoyable. Unless you do something to add a lot of weight, I would suggest a smaller parachute or else
make sure there are no winds unless you like to go hiking. I look forward to building other kits from Pemberton.
½ out of 5
(Contributed - by Jeff Boldig - 03/15/08)
Construction and Finishing:
The package was shipped with no damage. Packaging was excellent. The instructions were clear throughout and were
injected with a lot of humor. This was a good thing for me because it fits right in with my sense of humor and added to
my enjoyment of the kit. Your mileage may vary.
The instructions start out with a complete parts list including the fin alignment guides and patterns,
which are printed on the back page of the instructions. Step 1 of the "Assembly Destructions" was to check
everything against the checklist. Everything was present so on with the build.
The first assembly step is to use filler to fill the seams on the body tubes. This may not be your first step
with other kits, but I highly recommend following the destructions and doing it first. Unlike your standard fin rockets
where you can easily get to the body tube to fill seams after the fins are on, this won't work with the Kraken's tube
fins. Unless you don't fill seams at all, fill them first.
I had absolutely no problems following the destructions for marking up and cutting out the
tube fins. The text explains the process quite well and the pictures just make it that much clearer. Over half of the
destructions are devoted to marking and cutting the tube fins. Even if you can't read, the pictures would be enough to
get the fins cut out correctly. A new hobby blade was recommended and used. This is something that can easily be
overlooked, but shouldn't be.
Step 12 is actually a suggestion on how to finish the model. There are several suggested methods. I followed the
destructions pretty close. One additional step I used, which I use with almost all of my tubes, is to use CA along the
end of the tube. This soaks in the end grain of the tube and strengthens it. I used CA along all the edges of the fin
tubes and launch lugs. The destructions say to put ¼" tape on the fin tubes and the fin and launch lug
lines on the body tube where they will be glued together. I highly recommend this also. I put the tape in place, and
then I finished the filling and sanding of the fins and body tubes. I then primed all the parts, sanded, re-primed, and
sanded again until everything was ready for final paint. Don't forget to fill and finish the inside of the tube fins.
The launch lugs were a place where I varied from the instructions some. The kit comes with two one inch long
launch lugs. The pictures in the destructions seem to show two one half inch long launch lugs. I took each one inch lug
and cut the top one half inch with the same pattern used on the tube fins.
I really liked the black and red paint on the illustration of the model and used the same
pattern. I painted the inside of the tube fins and launch lugs red. If you are going to do this, I highly recommend
making sure you have a heavy layer of paint in the upper parts of the fin. I used rolled up paper to mask the inside
painted parts of the tube fins when I painted the remaining parts of the rocket. There was still a little overspray
that got onto the red parts. With a thick layer, you can sand the over spray off and then clear coat the whole thing to
get the gloss back. If you don't have a heavy enough coating to be able to sand off the overspray, you'll have to mask
the inside of the fins when you paint the rocket or mask the rocket and repaint the inside of the fins later. Both
methods will work, but I just don't like having to use masking tape if I don't have to.
The nose cone is another place where I varied from the instructions somewhat. The instructions call for sanding
and filling the nose cone before gluing on the canards. The recommended method of filling with CA, gluing the canards
on with CA, and then filleting with wood glue will probably work great. I just have a thing about using wood glue to
glue wood together. I sanded the nose cone and canards, glued canard to the nose cone with wood glue, filleted them
with more wood glue and then filled and finished the balsa. The destructions say to glue the ballast washer to the base
of the nose cone. I went a little further and scored one side of the washer with a file to give the epoxy I used a
little better grip when I glued it to the base of the nose cone.
The motor mount assembly went exactly according to the destructions. I didn't glue the
motor mount tube into the body tube at this time as the destructions said.
I painted the rocket first. I used a piece of rolled up paper to help hold and move the rocket during painting.
I also painted the lower part of the motor tube the same red as the inside of the tube fins. Once the paint was
done, I installed the motor mount.
Post flight note: The destructions say the motor mount should be recessed 1/8 inch into the body tube, for
aesthetics I assume. I mounted mine flush with the end of the BT. Considering the motor retention method used, I wish I
had extended the tube about ¼ inch beyond the BT.
I assume the parachute is a purchased item that is included with the kit. The assembly
instructions don't have any of the "funny" comments like the rest of the instructions. I varied from the
instructions some what on the assembly of the parachute. It said to cut the shroud line into six equal parts, attach
each to the and then tie the six together. I cut the shroud line into three equal lengths and attached three
loops to the parasheet. I then pulled the three together and looped them through a snap swivel.
The final assembly before the flight instructions was to tape a strip of masking tape around the Kevlar
shock cord where it leaves the body tube to prevent zippers.
This was a fun build that was not overly difficult. The instructions were very good and the construction was
straightforward. The only knock is the motor mount. Recessing it 1/8th inch may look better, but extending it ¼
inch would make it much easier the use the tape to retain the motors. As with any finishing, so much depends on the
modeler and the modeler's methods and standards. Because of this, I find it difficult to rate the finishing on a kit.
There were a lot of very good suggestions and instructions in how to construct the Kraken but not a lot of help on
getting a "great" finish. That lack of finishing help is the only reason I didn't make it 5 of 5.
½ out of 5
Flight and Recovery:
First of all, if this is your first rocket that doesn't have a motor retaining hook, don't worry. The destructions
are very clear on how to install a 24mm Single Use motor. They also cover how to prep the remaining items for flight
(e.g., wadding and parachute). As the destructions then say, "Go forth and go WHOOSH."
Flight 1 3/15/08 Battle Park Va. 3-8 mph winds, blue skies, and upper 50º. The first rocket to fly this day
was the Kraken. The motor was a recommended C11-3. The boost was nice and straight to about 500ft. The deployment was
right at apogee. The chute deployed great and had a perfect recovery. I was a little leery of the chute with the shroud
lines the same length as the diameter of the parasheet. This is typical but I believe it causes a lot more twisted
chutes then would happen if shrouds were 1½ to 2 time the parasheet diameter. I was pleasantly surprised, the
decent was great with no twisting or spinning on the way down.
Flight 2 3/15/08 Battle Park Va. 10-12 mph winds. A quick turn around made this the third
flight of the day. The motor was another recommended motor, a D12-5. This had a very straight boost to 800900
feet. The deployment was exactly at apogee, a perfect deployment. The wind was up a little and the decent was again
very good which meant a long walk.
Flight 3 3/15/08 Battle Park Va. 3 - 8 mph winds. I didn't have any of the recommended composite reloads, D15 or
E15, so I went a little bigger. This motor was an E28-7T. This was probably too much motor for this tube fin rocket. It
made 3 tight corkscrews as it flew under boost. It straightened out immediately after motor burnout. The altitude was
12001500 ft. The deployment was near apogee and was perfect. There was a long wait for it to come down but with
the light winds, it landed less than 300 ft from the pad.
½ out of 5
The destructions say the Kraken will "fly beautifully on C11-3 and D12-5 Black Powder motors" and they are
exactly correct. They also recommended the D15 and E15 composite motors. I'm sure these will fly just as well. If you
don't mind the tight corkscrews or consider it too much risk of losing a tube fin or two, the Kraken really grabs some
sky on the E28. I'm sure it will also survive and fly great on an F24. You're on your own with the F39. All in all,
this is a great kit. It looks great, flies great, and generates a lot of interest from fellow rocketeers.
½ out of 5