(07/01/04) The LOC Viper III is my third LOC kit and I purchased
it for the 24mm x 3 aspect. I wanted a cluster rocket that could fly on
D12's and E9's and the Viper III fit the bill.
The Viper III is a 47.5" tall rocket
based on a 2.6" with the cluster of motor tubes sticking out of
the bottom. The three fins are attached at the joints of the motor tubes.
Nothing terribly fancy about the rocket.
The kit includes a 30" long
and a 9" plastic . Then add the three 12" long motor tubes
that stick out 8 ½" to make up the 47 ½" total length.
There are two 1/8" plywood centering rings, three 1/8" plywood fins
(pre-cut), a recovery system and a . The recovery system consists of
a round 18" nylon and 96" (8') of 3/8" wide elastic
along with the standard LOC nylon loop for mounting the recovery system to the
Typical LOC instructions: printed on the back
of the 8½ x 11" card stock that displays the kit specifics through
the plastic bag that held the kit. There are only two illustrations, a rear
view and a side exposed view. These give some direction, however, the kit is
designed for those that have built some before and don't need picture-step to
picture-step guidance. The text instructions are clear and take the builder
from start to finish and give some insight into flying preparation. Also the
shock-cord mount has its own separate instructions.
The Viper III is really easy to build. LOC
recommends glue, but for fun I used Omni-Stick glue for everything but
the mount. I did this to test out the strength of this glue on a
bigger rocket. It takes some getting used to, but grabs quickly (formerly
called Quick Grab -
see here for
more info) and has adequate strength.
As I said, this rocket is simple to build.
Here's what you do:
- Glue Motor Tubes together
- Glue Centering Rings on Motor Tubes
- Glue Motor Tubes into Body Tube
- Glue on Fins
- Attach Shock Cord Mount
- Attach Shock Cord and Parachute
- Attach Nose Cone
That is it, really!
I didn't install LOC's launch lug, but
instead used Buttons.
I used my typical
for Kraft tubes and plastic nose cones. I then used Walmart Gold and Gloss
Black paint (additional comments
about Walmart paint). After waiting 1 week, I added vinyl letter that I
bought at Ben Franklin's and then hit the whole rocket with Walmart Clear
Overall, for CONSTRUCTION I
would rate this kit
½ points. The instructions are adequate and will get anyone that
has a bit of experience through this simple to build kit. It would be nice to
have lettering or decals. A bolt with nut could be glued between the three
motor tubes for retention, but for this rocket, I'm more understanding as to
why their isn't motor retention. Quality of parts was excellent and everything
LOC recommends three of the following motors:
D12-5, D21-7, E9-6, E15-7, E30-10, and F21-8.
LOC indicates the rocket should weigh 16
ounces. My rocket weighed in at 16.3 ounces (with the heatshield). Pretty
dead on, I would say.
I added a piece of Nomex®
heatshield and prepared for its first flight on D12-7's. I followed the
instructions and made a tape thrust ring and then each motor into
the motor tubes until they were all even. I then put in three Estes ignitors,
added the ignitor plug and then twisted the ignitor wires together in
Using my Estes Command Controller on 14.4V all three
motors ignited and lifted the Viper III to an excellent first flight. The
flight was perfectly straight and it was a perfect at ejection. Recovery
was good with a fairly fast descent rate on the smaller parachute.
I felt the rocket would life fine on three
C11-3's so I gave that a try. Unfortunately only two ignited and lifted the
rocket to about 25 feet, it turned and then a few feet from the ground ejected.
There was no damage.
The third flight was on three E9-6's.
Varooom! This was great! (see pic on right). Straight and good . It was
still heading up, but not at a fast pace when the popped the
parachute. The fast descent rate helps to keep it from drifting off.
For FLIGHT/RECOVERY, I would
rate this rocket
½ points. What a nice flier on Estes motors! The descent rate is
fast, but the rocket is sturdy and can take it. It would be nice to have a
piece of Nomex®
included in the kit, but since it isn't we recommend you get one.
I give the rocket an OVERALL rating of
½ points. The rocket is super simple to build. You can get away
with wood glue (or Omni) except you should use epoxy for the shock cord mount.
This is the type of rocket that can give the Estes-motor flier an entrance kit
into LOC/Precision. That can be a stepping stone into mid to high power.
Definitely a kit to consider.
(Contributed - by Cliff Oliver - 11/11/00)
Picture courtesy of LOC/Precision
This model is a single-stage, three-motor, cluster rocket. It was designed for
24mm mid-power motors. Primarily D and E motors.
In this kit there are one body tube, three motor tubes, two 3/16" plywood
centering rings, three 3/16" plywood fins, one 18" nylon parachute,
one elastic shock cord and mount, 1/4" launch lug and a plastic nose cone.
The instruction for this kit were structured for modelers that have built a
few rockets and understand how a rocket should be assembled. They explain the
areas of the kit that differ from others in good detail. The order of
construction was well thought out so you do not have to "go back" in
the construction process. This kit is very easy to build.
The only area I wish I had paid more attention was motor retention. LOC does
not include a method of retention in this kit. Which is good in my opinion. The
builder can choose his/her own method of motor retention. I had the rocket
completely assembled when I discovered how I wanted to retain the motors. The
tree motor tubes are epoxied together in a pyramid style. During construction,
a length of rod can be epoxied in the middle of the three tubes so
that it extends past the aft end of the assembly. This way, the motors can be
retained with a nut and washer. I had to "go back" and drill a hole
in the epoxy for the threaded rod. It works very well.
If you do not use the all-thread style motor retention, remember to seal the
gap between the motor tubes with epoxy. This will prevent venting the ejection
gases rather than deploying the recovery system.
All the parts fit very well. I did not have to sand any of the parts to
make them fit. I was a bit concerned about the fin method of fin attachment at
first. The aft end of the motor tubes extend past the aft end of the body tube.
This makes up a large part of the length of the rocket. The fins are attached
at the motor tube joints. No mounts here. However, A little
patience and a lot of epoxy in the fin to tube joints will pay off in the long
run. Also I suggest an epoxy in each motor tube joint. This will greatly
increase the strength of the lower end of the rocket.
All in all, using good construction techniques and EPOXY, the Viper III
turned out very sturdy.
The only "con" that I can say about this kit is the spiral grooves.
Need I say more? The grooves in the body tube were no worse than an Estes kit
though. I filled them with Elmer's and they turned out smooth and invisible
when primed and painted. The fins were coated with sanding and sanded
several times before priming. I used auto to start the finishing
process. One light coat. Then sanded smooth. Any imperfection were filled with
Squadron Green putty. Then primed and sanded until I was pleased with the
finish. Krylon "Glowing Lemon Yellow" fluorescent paint was applied
the to the main body tube. The nose cone, motor tubes and fins were painted
gloss black. There were no decals included in the kit. This allows the modeler
to add their own design. The model looks great after it's finished even without
out of 5
The recommended motors for this rocket are D12-7 and E30-7. I used three Estes
D12-5's for the first two flights. Cellulose insulation was used for .
This stuff works great! It's cheap and can be bought at almost any building
supply store. About three inches of the body tube full is enough. As I
mentioned earlier I used a piece of all-thread epoxied between the motor tubes
with a nut and washer for motor retention. I also epoxied thrust rings in the
motor tubes to keep the motor from moving forward. If you plan to use motors
longer than D's and E's, don't put any thrust rings in. Other motors will not
fit. The day I flew it for the first time was near perfect. 5-10 MPH winds
clear skies and the temp was around 80. I used the Estes ignitors that came
with the motors. I have an Ignitorman kit, but didn't have time to make some up
before this launch. Upon hitting the GO button the rocket lifted off very
quickly and straight as an arrow. Beautiful flight. I guessimate altitude at
approximately 1000'. Recovered close to the pads with no damage.
The shock cord is attached to the inside of the body tube using a small Kevlar®
string. The string is taped to the tube so that a loop extends one inch from
the end. Epoxy is applied other the end of the string and tape. This a very
strong mount. The included elastic shock cord is then tied to the Kevlar®
string. I tied a loop in the very end of the shock cord for the parachute to
attach. The nose cone was attached about 18" from the parachute. The set
up returned the rocket very nicely. It landed close to the pads at a rate that
did cause damage upon impact.
out of 5
This a great kit. I was kinda nervous about the first launch. It was my first
cluster rocket. It assembled and finished very well. The flight can be summed
up in one word. WOW! I haven't flown it on E motors yet. I can hardly wait.
out of 5
The following excerpt is from
"". The intention is to allow guests to get a basic
feeling about a kit. We strongly suggest that you get a copy of the referenced
Sport Rocketry and read the entire article. Inside you will find many helpful
hints in construction as well as other useful information. For more
information, use the two links above.
(Sport Rocketry - Sep/Oct 2000 - page 44 - by Bryan M. Chuck)
"The components are solid, quality parts: plywood fins and centering
rings, rugged cardboard tubing, plastic nosecone, and three 24mm
"A unique feature of this rocket is that the motor mount portion of the
rocket is exposed..."
"Building the Viper III was quite simple."
"The instructions are clear and easy to follow..."
"There are no decals with the Viper III."
"It's unique, yet simple to build, and a solid performer."
The entire article
gives the impression is that it a skilled modeler would enjoy this unique