©
2015 Madcow Rocketry™
Motor Mount Assembly
Step 1 - Lightly sand the glassine coating on the motor tube.
Glue will not stick very well to the glassine and roughing the tube
will help the glue stick.
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 4 - Insert one end of the motor clip into the slot cut in the
last step. Apply one full wrap of electrical tape around the motor
clip.
Step 5 - Slide the thrust ring into the top of the motor mount
tube until it rests against the top bend of the motor clip. Apply a
ring of glue at the thrust ring motor tube joint and smooth off the
excess with a fingertip.
Before gluing on the centering rings,
study the engine mount cross section below:
The aft centering ring is glued with 3/8”of the motor mount tube
exposed. This is important so the fin tabs will fit into their slots.
The forward centering ring is glued with 3/4”of the motor mount
tube exposed.
With a pencil, mark the tube 3/8” from the rear and 3/4” from the
forward end.
Step 6 - Line up the lower centering ring (slot on the inside
edge) over the motor clip. Slide the centering ring over the aft end
of the motor tube until there is 3/8" exposed. Apply wood glue
around the centering ring to hold it in place. Wipe off the excess
glue with a fingertip.
Let glue dry.
Step 7 - Glue the remaining upper centering ring (notch on the
outside edge) with 3/4" of the motor tube exposed. The ring will go
over the upper end of the engine hook.
3 1/4”
Cut
Slot
Step 3 - Cut a 1/8" wide slot
3 1/4" from the aft end of the
motor tube.
Tape Wrap
Thrust Ring
3/8”
3/4”
Aft
Forward
Step 8 - Wrap the yellow Kevlar
around the motor tube and tie
an overhand knot. Apply wood
glue over the knot to secure
it so it doesn’t come loose later.
Shock Cord Attachment
Mini Bomarc
Assembly
Step 24 - Glued the shaped conduit onto the body and wing
assembly. The stacked front section should but up against the
front of the wing. The back end should sit squarely on top of the
spacer piece between the wing and stabilizer.
Step 25 - Insert the vertical
fin into the slot and secure with
wood glue. Make sure the fin
root is flush with the back and
90 degrees to the horizontal
stabilizer. When the glue is dry,
apply fillets to both sides of the
vertical fin joint.
Step 26 - Glue a pod fin to a pod tube along the alignment line
drawn earlier. The pod fin should be flush with the front of the tube
and 90 degrees from the tube.
Step 27 - Apply fillets to both sides of the pod fin / pod tube
joint. Repeat for the other pod.
Step 28 - Make a mark 11 ½" from the front of the main body
tube on both pod alignment marks.
Step 29 - Glue the pods along the alignment marks on the
body tube with the front of the pod fin lined up with the 11 ½" mark
made in the previous step. Make sure the pods are 90 degrees to
the body tube.
Step 30 - Apply glue fillets to both sides of each pod fin / body
tube joint.
Step 31 - Glue the pod nose cones to the front of each pod.
Step 32 - Glue a launch lug near the aft end of the rocket in the
corner between the body tube and below the horizontal stabilizer.
Glue the other launch lug near the forward end of the wing in the
corner between the body tube and under the wing.
Ramjet Pod Assembly
11 1/2” from front of body tube
Launch Lugs
Launch Lugs
in line
View From Front