©2011 MadCow Rocketry™
FRENZY Assembly
Please make sure you read all directions and understand how
to assemble your model before you start construction. It is
also a good idea to test fit each part before assembly – some
manufacturing tolerances may require light sanding before final
assembly.
Laser cut parts will exhibit varying amounts of charring on the
edges depending on the density of the plywood. The charred
edges do not interfere with bonding and do not need to be
cleaned before assembly. In most cases the charring will be
cleaned up during sanding for finishing and painting.
Motor Mount Assembly
Step 1 - Sand the glassine coating off of the motor tube.
Epoxy will not stick very well to the glassine and roughing the
tube will help the epoxy stick.
1/2” Exposed
Hole
1/2” Exposed
No Epoxy
Here
Align eyebolt
this way
Not
this way
Step 2 - Test fit the centering rings over the motor mount tube
and sand if necessary. The ring should slide snug over the
motor tube without deforming it. Also test fit the centering
rings in the body tube and sand if necessary.
Step 3 - One of the rings will have a hole for an eyebolt to
attach the shock cord - this will be the forward ring. Spread
some epoxy on the outside of one end of the motor tube and
slide the forward ring (with the extra hole) until there is ap-
proximately 1/2” of motor tube exposed.
Step 4 - After the forward ring is dry, spread some epoxy on
the other side of the motor tube and slide the aft ring until
there is 1/2” exposed on the aft end of the motor tube. VERY
IMPORTANT: make sure there is not any epoxy on the mo-
tor tube between the 2 rings that would interfere with the
fin tangs later on.
Step 6 - Attach one end of the
shock cord to the eyebolt using
an overhand knot as shown.
Body Tube Assembly
Make sure centering
ring does not interfere
with the fin slot.
Step 7 - Wrap the shock chord into a small bundle and stuff it
inside the motor tube for this next step. Test fit the motor tube
assembly into the aft end (end closest to the slots) of the body
tube to ensure a snug fit. Sand the centering rings if neces-
sary.
Step 8 - When you are satisfied with the fit, spread some
epoxy on the inside of the body tube about 5” from the aft end
and slide the forward centering ring of the motor assembly
into the body tube.
Make sure you have the motor as-
sembly facing the right way - the centering ring with the
eyebolt should slide in first!
Keep going by spreading some more epoxy on the inside of
the body tube near the aft edge before sliding the aft centering
ring into the body tube. Continue sliding the assembly inside
the body tube until the aft centering ring is all the way in body
tube with the aft end of the motor tube lining up with the aft
end of the body tube. It’s a good idea to test fit a fin in each
slot here before the epoxy sets. Hold the body tube with the
motor tube assembly down until the epoxy sets. Make sure
the weight of the motor assembly doesn’t cause it to slide out
of alignment.
Step 5 - Mount the eyebolt using the nut and washer in the
forward ring hole. Apply some epoxy to the threads of the
eyebolt and nut to ensure it will not come loose later. Make
sure the eyebolt is aligned so that it will not interfere with the
body tube when the motor assembly is inserted into the body
tube later.
Fin Assembly
Step 9 - Using a door jam or small section of angle stock, pen-
cil a line halfway between two of the fins that extends from the
front to the back of the body tube. This line will be used later
to align the rail buttons.
