©2011 MadCow Rocketry™
FRENZY Assembly
Side of fin tang
Fin tang
edge
Fin root that would
contact the body tube
Forward Fin
Aft Fin
Forward
Aft
Step 20 - Apply some epoxy to the inside of the coupler and
push the bulkhead in so there is about a 1/8” to ¼” of cou-
pler exposed. After the epoxy has set, apply a fillet of epoxy
around the inside edge of the coupler bulkhead joint.
Fillets
3”
Payload Section Assembly
Step 19 - Insert the eyebolt through
the hole in the center of the bulkhead
and secure using the washer and
nut.
IMPORTANT: Apply some ep-
oxy to the nut and eyebolt threads
to ensure the nut doesn’t come
loose later.
Step 10 - Test fit each of the fins into the pre cut fin slots. The
fin should seat firmly against the motor tube - sand each fin if
necessary.
When you are satisfied with the fit, apply some epoxy to the
end of the fin tang that will contact the motor tube as well as
any fin root that will contact the body tube. Also, spread a
thin layer of epoxy on each side of the fin tang. Slide the fin
into place and check the alignment. Continue rechecking
the fin alignment until you are sure the epoxy has set. Clean
any excess epoxy from around the fin joint. Repeat for the
remaining fins.
Step 18 - Apply some
epoxy over the forward weld
nut inside the body tube.
Build up a smooth epoxy
bump over the screw so the
recovery system doesn’t get
hung up on the nut during
motor ejection.
Step 21 - Next mark the coupler 3” from the forward edge.
Apply some epoxy to the inside of the forward body tube sec-
tion and slide the coupler up to the mark. There should be
5” of coupler exposed. Make sure the coupler is straight and
the body tubes are aligned properly when they are assembled
later.
5” Exposed
Step 16 - Insert the weld nut from the inside of the body tube
through the previously drilled hole. You can hold the nut in
place with a little CA if you like (be careful not to get any of the
CA glue inside the threads. Place the rail button over the weld
nut and secure with the short 6-32 screw. It is a good idea to
use thread lock on the screw threads to keep it from coming
loose later.
Weld Nut
Rail Button
Step 17 - Site down
the rail buttons from
the aft end of the
rocket to ensure the
rail buttons are in
alignment.
Step 11 - Next, apply
epoxy fillets to both sides of
each fin. Carefully smooth
the epoxy fillets with your
finger before the epoxy
sets. Allow each fillet to set
before rotating the airframe
for the next fillet.
Step 12 - It is also a good idea to CA the sharp
tips of the fins to keep them from splintering on
hard landings.
CA
Super
Glue
Rail Button Attachment
Step 13 - Drill a 5/64” hole on the rail button line for the aft rail
buttons ensuring the hole goes into the aft centering ring.
Step 14 - Apply a small amount of epoxy in the hole and at-
tach the rail button using the supplied #6 wood screw. Make
sure the screw is loose enough for the rail button to spin freely
- this ensures the button is not compressed to the point it will
hang on the rail guide.
Step 15 - Drill a 3/16” hole on the rail button line for the
forward rail button. The forward hole should be 6” from the
forward end of the main body tube. IMPORTANT: Make sure
there is at least 6” from the forward end of the body tube or
the rail button will interfere with the coupler.
