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REV 2.4 - Tue Aug 17 10:57:52 2010

Pemberton
Kraken
2330 HWY 321 N
Ward, AR 72176
 
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SPECS: 22" x 1.6" - 4.4 oz
ROCKSIM FILE: Right Click to Download
SpaceCAD FILE: MISSING - please submit here
REC'D MOTORS: C11, D12, E9, D15, E15

Rating
(Contributed - by Les Bradshaw [Who's Who Page] - 02/16/08) Pemberton Technologies Kraken

Brief:
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 tube fin rocket. I felt what made it unique was how the tube fins were pointed.

Construction:
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" of Kevlar 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 paint.

The nose weight is a fender washer. This gets glued to the nose cone and a screw eye goes into the nose cone. The Kevlar 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.

Pemberton Technologies Kraken

Finishing:
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.

Construction Rating: 5 out of 5

Flight:
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 swivel)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.

Recovery:
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.

Flight Rating: 4 out of 5

Summary:
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.

Overall Rating: 4 ½ out of 5


Rating
(Contributed - by Jeff Boldig - 03/15/08) Pemberton Technologies Kraken

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 canard 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.

Pemberton Technologies Kraken 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.

Pemberton Technologies KrakenPemberton Technologies Kraken

Pemberton Technologies Kraken 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.

Pemberton Technologies Kraken 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.

Pemberton Technologies Kraken 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 parasheet 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.

Construction Rating: 4 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.

Pemberton Technologies Kraken 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 800–900 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 1200–1500 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.

Flight Rating: 4 ½ out of 5

Summary:
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.

Overall Rating: 4 ½ out of 5

[Submit your Opinion]

GUEST's OPINION:
09/08 - "I used a Estes D-E motor mount with a hook on my rocket it fits good and flew great!" (A.H.)

GUEST's OPINION:
04/08 - "The answer to the tube fin enigma is : Yes and Yes The photos on the website are of the soon to be released 3" MPR version, which has a slightly different fin to BT ratio and the angle of the rocket in the picture makes the BT appear shorter. We ended up using the MPR version for the pictures because the LPR demo bird died a fiery death brought on by a motor CATO just before the release date." (PEM.Tech.)

GUEST's OPINION:
03/08 - "Is it me or are the tube fins on the kit a lot shorter than the picture on PemTech's website? If you look at the picture, those tube fins should be about 9 inches long (assuming the body tube is 18 inches long). Perhaps the angle of the picture is a bit deceiving? Either way, that won't stop me from getting one. Great job PemTech!" (J.T.)

GUEST's OPINION:
03/08 - "About PemTech: I helped Layne edit the Kraken 'destruction manual', and I must say that it is laugh-out-loud funny in many places. ----- About this review: Excellent paint job. The yellow edging on the tube fins makes a great-looking kit look even better." (B.C.)

GUEST's OPINION:
02/08 - "I am not normally a fan of tube rockets, but when I saw this one I couldn't wait to read a review. Thanks for the information and build tips on a great looking rocket!" (K.G.)

[Enter Rocket Specific Tip]

SPECIFIC ROCKET TIP:
04/08 - "I agree with B.C. Install a motor hook and thrust ring. Recess it 1/8 to 1/4 inch. It will not effect stability may even increase it." (G.M.A. )

SPECIFIC ROCKET TIP:
03/08 - "Despite the manufacturer's recommendation, I would suggest adding a thrust ring and engine hook. " (B.C. )

[Enter Flight Log]
Date Name Motor Ejection/
Altitude
Wind Notes
01-18-2009 Jeff Austin Est SU C11-3 Apogee - NC Up 5-10 mph winds Flight PictureEvent: Frisco
- Perfect flight. Straight even with wind gust of 5-10 mph. Approx 400' altitude. 18 Chute is definitely oversize. 5 straight flights without issue. Nosecone detached from shock cord mount on flight 6. Minor repair.
01-18-2009 Jeff Austin Est SU C11-3 Apogee - Perfect 5-10 mph winds Event: Frisco
-
01-18-2009 Jeff Austin Est SU C11-3 Apogee - NC Up 5-10 mph winds Event: Frisco
-
01-18-2009 Jeff Austin Est SU C11-3 Apogee - NC Up 5-10 mph winds Event: Frisco
-
01-18-2009 Jeff Austin Est SU C11-3 Apogee - Perfect 5-10 mph winds Event: Frisco
- Nosecone separation from shock cord mount. Minor repair.
12-28-2007 Donald Besaw Est SU C11-5 Just Past (1-2sec) 0-5 mph winds - Excellent first flight, shot up straight as an arrow to maybe 500-600 feet. Great recovery on an AT 15 inch nylon chute. Next up, D12. No damage.
05-15-2008 Donald Besaw Est SU D12-5 Didn't See 0-5 mph winds - Excellent flight, nice fast and straight boost. Sustained an ever so slight zipper, easily fixable with some CA. No other damage.
03-15-2008 Jeff Boldig Est SU C11-3 Apogee - Perfect 0-5 mph winds Event: Battle Park
- Great first flight!
03-15-2008 Jeff Boldig Est SU D12-5 Apogee - Perfect 5-10 mph winds Event: Battle Park
- This second flight was better then the first. About 800-900 feet.
03-15-2008 Jeff Boldig AT RMS E28-7 Apogee - NC Up 0-5 mph winds Event: Battle Park
- This might be two much motor. 3 corkscrew while boosting. Straightened out at motor burnout. about 1200 to 1500 feet.
11-01-2008 Jeff Boldig Est SU D12-5 None - Parachute Fail
(600 ft)
0-5 mph winds Event: Battle Park
Kraken II - used too much dog barf and the chute caught on the tape on the shock cord that is to prevent zippers and never deployed. It might have chipped a little paint, but no other damage
06-15-2008 Jeff Boldig Est SU D12-5 Apogee - Perfect
(800 ft)
10+ mph winds RIPEvent: Pole Green Park
- Great flight. I put tape thrust ring on motor. Getting it taped to MMT inside the BT is harder. I think it kicked the motor. It drifted very far. Last seen over the woods .25 mi away and actually gaining altitude. Status: Lost
02-21-2009 Jeff Boldig Est SU E9-6 Apogee - NC Up 10+ mph winds RIPEvent: Battle Park
Kraken II - Great straight and high flight. Glad I didn't use the 24/40 casing. It drifted away. Looked like it never lost altitude. Got to 500 ft and stayed their, just moving away on the wind. Last seen when it got too far away to see with binoculars. Status: Lost
02-16-2008 Les Bradshaw Est SU D12-3 Just Before Light winds - Motor ejected as well as parachute. Due to cold, chute did not fully open until 20' above ground. No damage
02-16-2008 Les Bradshaw Est SU D12-3 Just Before Light winds - Friction fitted the motor, so motor did not eject. Parachute opened immediately. Took a long time to drift down
02-16-2008 Les Bradshaw Est SU D12-3 Just Before Light winds - Chute ejected and opened after a short fall. Winds had picked up so it drifted a distance away. Would recommend a smaller chute (an 18 chute is too big)
01-19-2008 Jewel Butler Est SU D12-5 Apogee - NC Down 5-10 mph winds Event: Nasa Houston Tx
- The Kraken is one of my most striking looking rockets in my inventory.The rocket is very easy to build if you read the instructions very carefully.The flight was so impressive that I built a 29mm version and a 18mm version
05-04-2008 Jewel Butler AT RMS F39-6 Didn't See 5-10 mph winds Event: NASA JSC
- The lift off was incredible nobody got pictures
05-04-2008 Jewel Butler AT RMS F39-6 Didn't See
(1200 ft)
5-10 mph winds Event: NHRC Contest
- went off so fast all I saw was the smoke
12-29-2008 Jewel Butler Est SU D12-5 Apogee - NC Down 5-10 mph winds - Beautiful straight up flight very quick off the pad.Flew aprox.700 to 800 with D12-5
09-13-2008 Andy Hansom Est SU E9-6 Just Past (1-2sec) 5-10 mph winds Event: ROCstock
- Nice flight with a little weather cocking. I think it needs more than a 9 to push the rocket into stable flight.
10-18-2008 Andy Hansom AT SU E30-7 Just Past (1-2sec) 5-10 mph winds Event: October Skies
- Fast off the launch pad. no damage
10-18-2008 Andy Hansom Est SU D12-5 Apogee - Perfect 5-10 mph winds Event: October Skies
- Very nice flight. no damage
03-14-2009 Andy Hansom AT RMS F35-7 Didn't See 0-5 mph winds - Way to fast and way to high. Can't wait to do it again. Needs a smaller chute using this motor long walk to retrieve
03-14-2009 Andy Hansom AT RMS F35-7 Didn't See 0-5 mph winds - Another nice flight. Super fast of the pad and way up there. Used a Top Flight 12 thin mill chute. Still takes a long time for the rocket to come down
12-21-2008 Mike Lysic Est SU C11-3 Apogee - NC Up 0-5 mph winds - Beautiful straight straight straight boost, slight tailslide at apogee(less than a foot). Chute ejected but didn't open until about 100 feet from the ground relieving the anxiety that was quickly setting in. Great flight. No damage.
03-14-2009 Mike Lysic Est SU D12-5 Apogee - NC Down 0-5 mph winds Event: Gumbert's field
- Flies great on this motor. Went a little higher than expected, BONUS! Rcovered pretty close to pad with no damage. I can't wait to fly this one on an AT D-15 or an E-9.
04-11-2009 Mike Lysic Est SU D12-5 Apogee - NC Up 5-10 mph winds Event: Gumbert's field.
- Good straight boost. 5 second delay is a little short, should be 7 seconds. Still a good flight.
06-08-2008 Mal McClenaghan Est SU D12-5 Just Past (1-2sec) Calm Event: Dandenong Wetlands
- Beautiful straight boost. Weak ejection charge. Landed in tree. Recovered.
06-08-2008 Mal McClenaghan Est SU D12-5 Didn't See Calm Event: Dandenong Wetlands
- Straight boost. Nice recovery on a 14inch nylon chute.
07-12-2008 Dave Olson Est SU D12-5 Apogee - NC Up 5-10 mph winds Event: ESL 122
- Nice straight flight - chute was a little big - long walk for recovery - wish a had a little longer delay too.
07-12-2008 Dave Olson Est SU D12-5 Apogee - NC Up 5-10 mph winds Event: ESL 122
- Smaller chute, less walk.
07-12-2008 Dave Olson Est SU E9-8 Apogee - NC Up 5-10 mph winds Event: ESL 122
- Eject was almost perfect. E's charge was a litle too strong as the nose cone was lost (pulled the eye screw - it was CA'ed in - I swear!) A little longer shock cord should work better next time.
   

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