RocketReviews.com - Estes - BLU-97B Cluster Bomb (1246) [2003-2003]

Brief:
I was doing a rocket launch for Science Day at my kids' school. Since the field was small, I wanted something slow and low. Since the spectators were young, I wanted "something special" and I thought the "spits out nerdlets on streamers" factor would be a big plus. Since I wouldn't have time to reload between classes I knew I would have to build 6 rockets of each type I was launching (the Snitch, and Cosmic Cobra were the other two types I chose), so cheapness and Level 1 construction were a must. And since there was no way I could call or finish these as "Cluster Bombs" for little kids, I thought the 10" long fat tube would be perfect for a colorful wrap.

Wel,l I was right on 4 out of my five requirements. The only one I was wrong on was that these were Level 1 construction projects. A combination of poor design and shoddy parts made building 6 of these far more time-consuming and aggravating than I expected. I knew these were ridiculously cheap rockets, considering the number of parts, but these kits weren't up to the usual Estes standards. A Mosquito is a Level 1 rocket. An Alpha is a Level 1 rocket. A motor-mount-overhang, two-part-boat-tail, through-the-wall-fins, clay-in-the-two-part-nosecone is not a Level 1 project. Add in parts that don't fit and an unsecured aft motor mount and you're closer to a Level 3.

The first “gotcha” is in the motor mount. The construction is the usual Estes type, with the difference being that both centering rings are far forward of the engine hook. You're instructed to place a mark inside the aft end of the body tube and then glue the mount in place. If you do this before you do the next step, building the boat tail (“tail cone”), you can't use the tail to line up the motor mount. The aft end of the motor mount appears to be designed to end just short of the end of the tail cone, leaving it unsecured at it's aft end. Since I read the directions prior to gluing in the motor mount, I built the boat tail first thinking the aft end of the motor mount tube must rest in the end of the plastic boat tail. But the end of the boat tail is of a smaller diameter than the motor mount tube (it's the same diameter as a motor). Thus it's the motor itself that provides lateral stability for the motor mount tube. What's really needed here is either another, smaller, centering ring, or some flanges inside the boat tail that center and stabilize the motor mount. It's not that this is such a high performance product that this is critical for flight, but it means the motor-mount tube moves all over when you are trying to check the fit of the through-the-wall-fin fin-tabs. Basically you need to insert a motor while you're building the rocket in order to adjust the length of the fin-tabs.

The second “gotcha” is that on all six kits the notch in the boat tail, through which the engine hook is to fit was too narrow for the width of the hook. I simply enlarged it on the first rocket I put together before realizing I'd been had by the third “gotcha” which is that the notch is directly in line with the fin slot in the boat tail. This means you're supposed to glue that fin to the engine hook? This is the only rocket I've ever built suggesting you insert a lever between the fin and body tube! For the remainder of the rockets I Dremeled an engine-hook notch at a spot halfway between two fin slots. Really not a Level-1 construction technique.

The final “gotcha” was the fins and fin-slots. The directions tell you to “Test fit fins in slots on tail cone. Sand as needed for a proper fit.” Easier said than done since this was a two-part “gotcha”. The fin-slots on all six rockets were significantly narrower than the fin stock. Okay, you're probably going to have some variance in fin stock so err a little on the narrow side for the slots to make sure the fins are tight. A little sanding would be OK. But the difference between the two was really significant, probably 25% of the fin width. For the first rocket fin (out of the 24 I did) I tried alternately sanding one side of the fin tab, then the other, trying to keep the fin tab centered in the fin. That was such a pain that I eventually decided to widen the fin slots. I eventually figured out that folding a quarter sheet of 220 sandpaper lengthwise in half, and then in half again, produced a giant sized “emery board” that could be slipped through two fin slots at once and would fairly quickly enlarge the slots enough to take the fins.

The second part of this “gotcha” was that now that I had fins that fit in the slots, the tabs were too long. The directions tell nothing about this but the solution I came up with, because of the unsecured motor mount, was to insert an engine (the yellow engine spacer is too flimsy), write a number on each fin and corresponding fin-slot, and sand the tabs to fit. Okay, after the fins are all glued in place they do act to center-stabilize the motor-mount tube. But unless you figured out some way to hold the tube in place while sanding the fins to fit, you're going to end up with an off-center motor-mount. One that you probably can't even slide an engine into considering the proximity and narrowness of the aft end of the boat tail. Again, not really a Level 1 technique.

As for the rest of the assembly, it was fairly straightforward. If you've built lots of rockets before, there are no show-stoppers. But there's no way anyone should think of buying this kit for someone's first rocket. If you haven't built a number of rockets with motor mounts and through-the-wall fins, this kit would be extremely frustrating.

As for finishing, I made colorful wraps to size on my computer and printed them out from my inkjet printer on full-size label paper. The best technique I found was to put a little centering mark in the center of the top and bottom of each wrap. I drew a centering line down the middle of each rocket using a piece of aluminum angle-iron. (Because I had already put the launch lugs on, I put my line on the opposite side of the launch lugs. I've used this technique again since, but I do it before putting on the launch lugs, then cut out a small spot for the lugs.) I then cut the wraps to size, and tore away a thin strip of backing paper down the middle of the wrap. I lined it up at top and bottom, then pressed it into place, starting from the center and working out toward the top and bottom of the tube. I then removed the backing paper from one side at a time and, working from the center out towards the back side of the rocket, repeated the sequence. It works well, avoids bubbles, and allows for better alignment than trying to line up one edge of the wrap with the centering line. If you make your background color black, you can fill in any tiny gap on the back side with permanent marker (I also used permanent marker to color the launch lugs). I then sprayed the wrap with two coats of Rustoleum clear, and let those dry for 24 hours before masking off the body to paint the fins and tail. I painted the clear first because I wanted to be sure the masking tape wouldn't ruin the paper wrap. Be sure to test whatever spray you're using first on some scrap wraps because one of the acrylic clear coats I tried made all the ink run. The clear coat soaks through the paper so whatever is underneath will show through any light areas. For that reason I erase all but the very top and bottom of my centering line before putting on the wrap. I also spray non-white tubes white when using the technique on other rockets for the same reason. If you've not done this technique before, you'll be surprised at how vibrant the inkjet colors turn after you spray them with the clear spray paint (see photo). The size and color of the body tube, as well as the cost, on this rocket make it perfect for your first attempt at a wrap.

As for flying, in spite of all the construction problems, this is a real crowd pleaser. It flies great, and is sturdier than I expected. I used B6-4s to keep the ejection low enough so the kids could see the action. Be sure to keep the rod straight up though when using B's. These rockets only hit 150' max on a B so angling the rod on my first shot caused an almost-lawn-dart (which the kids liked anyway). I basically think of this rocket, with colorful wraps, ejecting nerdlets, and flown on B-engines, as a big version of a New Year's Eve “Party Popper”.

All in all, I'd give this rocket a 5 for flight, a 5 for Potential Creativity, and a 1 or 2 for construction. If Estes cleans up the construction problems it should be in their lineup for a long time to come.

Flight Log

Date	Rocket Name	Motor(s)	Altitude	Notes
2003-09-07	Max Handly's Estes BLU-97B Cluster Bomb	B6-4	100 feet	Strait flight on a B6-4, up to about 100 feet, nice pitch over for a perfect bomblet delivery....
2003-10-11	Donald Besaw's Estes BLU-97B Cluster Bomb	B6-4	-	Nice first flight and a nice bomblet deployment. Landed close to pad. No damage.
2003-12-13	Donald Besaw's Estes BLU-97B Cluster Bomb	C6-3	400 feet	Very nice boost, straight as an arrow up to about 400 feet. Deployed bomblets exactly as intended,...
2003-12-28	Stephen Peart's Estes BLU-97B Cluster Bomb	C6-5	-	First flight. Katie retrieved the bomblets. Weathercocked a little.
2003-12-28	Donald Besaw's Estes BLU-97B Cluster Bomb	C6-3	-	Nice flight and a nice bomblet deployment. I recovered all 4 with no problems and the rocket was...
2003-12-31	Scott Hauff's Estes BLU-97B Cluster Bomb	C6-5	-	Fun Rocket. Bit of weathercocking into the wind. Close recovery of all bombs and rocket.
2004-01-12	Jason Vennard's Estes BLU-97B Cluster Bomb	C6-3	-	Nice flight, little windy today so slight weathercocking but it was expected. Cluster bombs...
2004-01-25	Donald Besaw's Estes BLU-97B Cluster Bomb	C6-3	-	Went almost horizontal on takeoff. The late ejection stripped the chute which resulted in two...
2004-04-02	Serge Zoruba's Estes BLU-97B Cluster Bomb	A10-3	-	Tried a very slow take-off with an A10-3T motor. Went up very slowly to only 60 feet, nose turned...
2004-04-10	John+Eric Thompson's Estes BLU-97B Cluster Bomb	C6-3	-	launched the rocket three times that day on the same motor. Perfect flight each time.
2004-05-08	Jason Lenentine's Estes BLU-97B Cluster Bomb	C6-3	-	Good flight with a little too much altitude. Bomblets were hard to track after deployment....
2004-05-22	Jason Vennard's Estes BLU-97B Cluster Bomb	C6-3	-	Nice flight, little early on the delay ejected nosecone up and all bomblets stayed inside rocket....
2004-06-05	Matt Vennard's Estes BLU-97B Cluster Bomb	C6-3	-	A decent flight, but this seems to be underpowered on a C. Not much height at all. Bomblets...
2004-06-08	Donald Besaw's Estes BLU-97B Cluster Bomb	C6-3	-	Very nice flight up to about 350-400 feet. Everything recovered OK. No damage.
2004-09-05	Jason Lenentine's Estes BLU-97B Cluster Bomb	C6-3	-	Good flight.
2004-12-26	J Bolduc's Estes BLU-97B Cluster Bomb	C6-3	-	Nice flight on a C6-3. Estimated 300` to 350`. All 4 bomblets recovered (2 with minor...
2004-12-26	J Bolduc's Estes BLU-97B Cluster Bomb	B6-4	-	First flight for this rocket. Very low flight 100` or less. Ejection came at about 50` after a...
2004-12-29	Scott Hauff's Estes BLU-97B Cluster Bomb	C6-5	-	Cool Rocket to fly. Turned into wind just a bit. More altitude than expected. 5 sec delay WAAAAAAY...
2004-12-31	Marc Hoenstine's Estes BLU-97B Cluster Bomb	B6-4	-	This was the BLU's first launch. It didn't go very high, but it was a very nice launch. The...
2005-02-23	Donald Besaw's Estes BLU-97B Cluster Bomb	C6-3	-	Nice flight, long arcing boost. Everything recovered without incident. No damage.
2005-03-26	Peter Reed's Estes BLU-97B Cluster Bomb	C6-5	-	another great flight, delay too long though. one of the parachsute guys got a little singed and...
2005-03-26	Peter Reed's Estes BLU-97B Cluster Bomb	C6-3	-	second flight of the day, reloaded with two dollars store parachute guys, landed less than 100...
2005-03-26	Peter Reed's Estes BLU-97B Cluster Bomb	C6-3	-	great flight, loaded it up with two dime sotre parachuste guys, they seemed to float forever,...
2005-05-14	Michael Mangieri's Estes BLU-97B Cluster Bomb	B6-2	-	Maiden flight of this rocket. Nice boost, low and slow. Good performer on this motor.
2005-07-04	Michael Mangieri's Estes BLU-97B Cluster Bomb	B6-4	-	Nice boost - very straight. All went well.
2005-07-04	Michael Mangieri's Estes BLU-97B Cluster Bomb	C6-3	-	Great liftoff and boost - she really took to the sky. The released bombs landed in a 20'-30'...
2005-09-11	Daniel Griswold's Estes BLU-97B Cluster Bomb	C6-3	-
2005-11-19	Tim Dicke's Estes BLU-97B Cluster Bomb	E18-7	-	I love this motor. It really roars off the pad! This rocket flies so straight. Recovered on a...
2005-12-17	Tim Dicke's Estes BLU-97B Cluster Bomb	E28-7	1599 feet	Everyone watching missed the takeoff because we thought there might be a launcher problem. Came...
2005-12-29	David Allen's Estes BLU-97B Cluster Bomb	C6-3	-	Weather cocked slightly as it always does. Very good and predictable flier.
2006-01-15	Tim Dicke's Estes BLU-97B Cluster Bomb	E28-7	-	A real neck snapper! Great flight recovered under 3inch streamer.
2006-01-15	Dave Brunsting's Estes BLU-97B Cluster Bomb	C6-3	-
2006-01-28	Tim Dicke's Estes BLU-97B Cluster Bomb	E28-7	-	Wow! It always gets a good laugh out of everyone. I love this motor for this rocket. Very fast!...
2006-03-03	Bob Shaw's Estes BLU-97B Cluster Bomb	C6-3	-	Overall good flight and recovery.
2006-03-03	Bob Shaw's Estes BLU-97B Cluster Bomb	B6-4	-	Nice flight, good deployment of bomblets, great recovery.
2006-03-26	Tim Dicke's Estes BLU-97B Cluster Bomb	E18-7	-	Zoom! I love to fly this rocket on AP motors. It really scoots and always surprises everyone...
2006-06-25	Tim Dicke's Estes BLU-97B Cluster Bomb	F20-6	-	Wicked ride! Marginally stable as about 4in of motor was sticking out of the back end of the...
2006-07-08	Ed Scientist's Estes BLU-97B Cluster Bomb	C6-3	-	I love it. Nice high flight. I tried a 10 inch mylar chute worked great but I think I got...
2006-07-15	Ed Scientist's Estes BLU-97B Cluster Bomb	B6-4	-	Not high but a good flight all the same. Landed in the hard rocky dirt...should have listened to...
2006-08-05	Tim Dicke's Estes BLU-97B Cluster Bomb	D12-5	-	I think the deployment was pretty early but I was surprised by the launch and looked away just at...
2006-08-19	Michael Mangieri's Estes BLU-97B Cluster Bomb	C6-3	-	Cool flight. Kids loved it as the four cluster bombs dropped alongside the rocket.
2007-03-25	Tim Dicke's Estes BLU-97B Cluster Bomb	E28-7	-	This rocket screams on this motor! I never get tired of that motor in this rocket. Used a...
2007-09-22	Tim Dicke's Estes BLU-97B Cluster Bomb	E28-7	-	Didn't get my personal alarm to start but didn't need it anyway (landed in the short grass).
2007-11-10	Tim Dicke's Estes BLU-97B Cluster Bomb	E28-7	-
2008-05-31	Dwayne Shmel's BLU-97B Cluster Bomb	C6-5	-	Perfect First Flight.
2008-06-21	Dwayne Shmel's BLU-97B Cluster Bomb	C6-5	-	Nice flight. Good recover on 14 nylon chute.
2008-07-26	Dwayne Shmel's BLU-97B Cluster Bomb	D13-7	-	Awsome flight - very fast and high. The rocket was well on it's way back down when the chute...
2008-09-20	Tim Dicke's Estes BLU-97B Cluster Bomb	F12-5	-	Went waaaaay up waaaaay fast!!!
2008-09-27	Dwayne Shmel's BLU-97B Cluster Bomb	C6-3	-	Parachute tangled. Slight damage at ejection.
2008-10-25	Dwayne Shmel's BLU-97B Cluster Bomb	C6-3	-	C12-4T reload was used.
2009-03-07	Tim Dicke's Estes BLU-97B Cluster Bomb	D12-5	-	Came down on a streamer. Not a bad walk considering the wind.
2009-03-28	Dwayne Shmel's BLU-97B Cluster Bomb	C6-5	-	Drag race with David S - I lost. Meant to use C6-3, oops.
2009-04-04	Tim Dicke's Estes BLU-97B Cluster Bomb	E28-7	-	Wow! Bang, zoom, gone.
2009-04-04	Dwayne Shmel's BLU-97B Cluster Bomb	C6-3	-
2009-05-03	Dwayne Shmel's BLU-97B Cluster Bomb	C6-3	-	Love the long burn quest motors. This is the perfect rocket/motor combo unless you step up to the...
2009-05-30	Dwayne Shmel's BLU-97B Cluster Bomb	C6-3	-
2009-06-06	John Bergsmith's Estes BLU-97B Cluster Bomb	C6-3	-	Another nice flight, great flyer! Recovered with no damage.
2009-06-06	John Bergsmith's Estes BLU-97B Cluster Bomb	C6-3	-	Flight number two on the day, and another great flight.
2009-06-13	Dwayne Shmel's BLU-97B Cluster Bomb	D24-7	-	Ejection charge failed to ignite. Rocket went straight up and right back down. Irreparable damage.
2009-06-20	Tim Dicke's Estes BLU-97B Cluster Bomb	F39-9	-	Very cool boost. Popped a fin landing on hard ground. Easily repaired.
2011-05-07	Dwayne Shmel's BLU-97B Cluster Bomb	D21-4	-	First flight of rocket after replacement of body tube.
2011-07-02	Dwayne Shmel's BLU-97B Cluster Bomb	C6-5	-	Chute tangled and rocket fell fast. Slight damage to BT.

Estes - BLU-97B Cluster Bomb (1246) [2003-2003]

Flight Log

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