(06/10/98) The things people say
are not always nice. One might be called a fat boy, while another is called
Brothers went for the latter with their 2.6" short-body kit. The
BlobboÔ is powered by 18mm motors and is 16.5" tall and weighs about
4.5 ounces. See
my 2.6" Stubby Rocket Comparison Page
The kit comes with an 8.25"
single body tube and a 8.25" plastic nose cone. Its 18mm motor mount
comes with 1/32" laser-cut plywood centering rings and a motor retention
clip. It uses precut fiberglass fins with through-the-wall mounting. It
comes with an 18" bright-yellow rip-stop nylon parachute, a 36"
elastic shock cord (1/4" flat) which attaches to a thin metal shock cord
mount. It also includes a single launch lug and there are no decals.
There are only three pages of instructions and one of
those pages is nothing more than an illustration of the side and bottom view of
the rocket with an alignment guide. This kit is not for the new modeler due to
its lack of instructions. In all fairness, the instructions are in a logical
order and good enough to get an experienced modeler through the kit assembly.
There are a couple of challenging steps that I'll touch on below. The kit does
not have a rated skill level (as far as I know), however, I think it falls at
about a 3.
When building the motor mount, the instructions say to
cut a "slot in the motor tube 0. 20 inches from one end for the motor
hook". How many modelers keep a ruler using divisions in tenths around? I
don't. I don't. By reviewing the drawing, the appropriate distance can be
determined by adding a 0.25" centering ring spacing to the 2.25"
spacing between centering rings. The motor hook is supposed to be 2.5"
from one end.
The motor hook was held in place with a "Motor Hook
Strap". This seemed to me to be a piece of tack cloth that gets saturated
with glue to hold in place. It did the trick.
The remaining assembly of the motor mount requires
notching one centering ring to allow clearance for the motor hook and notching
the other to allow for clearance of the shock cord mount. The shock cord mount
attachment is very interesting. First off, the shock cord mount looks like a
fishing leader with a crimped-loop at each end. To attach this, the larger loop
is placed over the motor tube and the top centering ring is positioned to hold
it in place. This is somewhat challenging since the loop is to be on one side
of the ring and the crimp is to be on the other. Once together, it puts the
paper mount to same!
The next step also was somewhat challenging in the fact
that accuracy was required. This was cutting the slots in the airframe to allow
each fin tab to slide in. This cut requires a good and sharp hobby knife to
give clean cuts. Might be time to change the blade in yours.
The instructions are good in the fact that they tell you
to rough up the fins where the fillets are applied and that the fins can be
attached using CA, however epoxy fillets are recommend for strength.
Now that everything is assembled, glued, fillets applied
and recovery system attached, its time to prepare for finishing. Again the
instructions say to lightly sand the body tube and fins and to prepare the nose
cone by removing any molding flashing and lightly sanding.
Using Plasti-Kote primer, I filled in the body
tube grooves and cleaned up the small pits in the plastic nose cone left by the
molding process. I must say that I really enjoyed prepping the fiberglass fins.
Very easy, compared to the tasks required to get balsa fins to finish smoothly.
Used another can of $0. 98 Walmart enamel. This time a
deep green. Since the kit didn't come with any decals, I felt it looked a bit
plain so I added a yellow pattern to the fins and then covered the entire kit
with Walmart's Clear enamel.
Just a comment on the pro's
and con's of this $0. 98/car Walmart spray enamel: The pro's are the cost and
durability, which seems every bit as good as other brands I've used. The con's
are color selection, however for $1. 39/can you can improve your color
selection and still not pay the standard $2. 49+ for other popular brands.
Another con is according to instructions, additional coats must be done within
4 hours or after 1 week. So in the case of my BlobboÔ, I have
to wait a week before I completed the fin pattern with a second color. But,
after the second color and within 4 hours, I hit the whole rocket with clear.
If you're not in a hurry, I think, the pro's outweigh the con's with this
Overall, for CONSTRUCTION I would rate
points. Again if you have some rocket building experience, the
instructions can get you through without much problem, but I see this kit as
being an entry level kit and to reach the beginner modelers improved
instructions could go a long way. Lastly, the kit needs a decal.
Whether you call it a "fat boy" or as
the more appropriate BlobboÔ, there is one thing you can
say about anything with excessive girth . . . it's going to be a slow starter.
And indeed, the BlobboÔ, loaded with its "first
flight" recommended motor, a C6-3 had a slow start. But like the turtle
and the hare, a slow start (lift off) is not always a bad thing. In this case
the BlobboÔ gave us a great race, snapping across the finish line and
ejecting right at apogee. The slow lift off allowed more time to see it and
I'm not very good at guessing altitudes, but Apogee's
indicates it should have gone about 235 feet. This is a good height for the
wind we had on launch day (10-15 mph gusts). It did weather-cock quite a bit,
which is probably due to the short, fat body and larger fins. Regardless, the
BlobboÔ delivered a successful flight and recovery.
Upon inspection, the piece of
Perma-WaddingÔ held up well, however, I
think I need a larger piece for this diameter of rocket. In all fairness, the
size I'm using is recommended for a 1. 3" body tube and the
BlobboÔ is double that size.
The parachute, shroud lines and shock cord system all
demonstrated performance and showed no sign of wear or damage. The metal leader
and 1/4" elastic system seems to be strong and sturdy and should be
durable for many, many flights.
Vaughn Brothers only
gave two recommended motors to fly the BlobboÔ on; the C6-3 and a D21-7.
The D21-7 is a Single-Use Aerotech motor. I decided
to try the new Apogee D10-7. Knowing
that my delay was too long, based on RockSimÔ, I decided to load it up
Everyone was excited to hear the flight coordinator
announce that this would be the Apogee D10, however, we got an
unexpected surprise. 3, 2, 1 - BOOM! The rocket shot up about 75 feet and nose
dived into the ground. The casing had exploded! The propellant was still mostly
there, with a larger (rounded) groove. The case blew out the motor mount and
cracked the bottom centering ring. The upper part of the motor was still stuck
in the rocket and the ejection charge still intact. BlobboÔ took a
hit worse than name calling!
Things that make you go hmmmmm? and a
MESS form was filled out.
Well, BlobboÔ has been repaired and is
ready for it's next launch. I'm out of D10's but will try that one again later.
Hey, you can't condemn a motor for one CATO. If that was the case, how many
would still be flying Estes' D motors? Those things have ate my Estes
BroadswordÔ and blew apart the top of one of my launch pads.
The next day I tried to get a launch
picture on Estes C6-3's. I had two more successful flights with the nice slow
lift offs. The second flight really weathercocked and flew parallel to the
ground most of the way. Some minor damage on bottom of body tube due to it
hitting the concrete roadway.
For FLIGHT/RECOVERY, I would rate this kit
Overall, this kit is easy to build if you have some
experience under your belt. It's fun to fly too, with slow take offs. And it
can take a 75 foot nose dive with little affect (don't purposely try this). I
give the kit an OVERALL rating of