2 ©2018
MadCow
Rocketry™
Mantis™
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.
Fiberglass parts still contain small amounts of mold release and other materials on the
surface that will inhibit adhesives and/or paint. It is important to clean each part prior
to assembly with a solution of 1 part rubbing alcohol, 3 parts water and a drop of dish
washing soap. IMPORTANT: do not sand any parts until after you have cleaned them -
you will embed the materials you are trying to clean making it difficult to clean.
The G10 parts will have holding tabs left over from the CNC machine. These small tabs
will need to be sanded off before assembly. Before assembling any part with epoxy,
rough up the surface to be epoxied using course sandpaper. The scratches in the G10
surface will give the epoxy something to grab onto.
Step 1 – Motor Mount Assembly
Test fit the centering rings over the motor mount tube and sand if necessary. Also test
fit the centering rings in the body tube and sand if necessary. The ring with the 1/4” hole
for an eyebolt will be the forward ring. Spread some epoxy on the outside of one end
of the motor tube and slide the ring (without the hole) until there is approximately 1/2”
of motor tube exposed. Make sure you clean the motor tube of any epoxy so as not to
interfere with the fin tangs later. After the aft ring is dry, make a mark 1” from the other
end of the motor tube. Spread some epoxy on the motor tube and slide the forward ring
until it aligns with the mark.
VERY IMPORTANT: make sure there is not any epoxy on
the motor tube that would interfere with the fin tangs later on. Also test fit one of
the fins to make sure there is enough room for the fin tang between the centering
rings.
Mount the eyebolt using the two nuts
as shown in the forward ring hole.
Apply some epoxy to the nuts to
ensure they will not come loose later.
Attach one end of the shock cord
to the eyebolt using an overhand
knot.
IMPORTANT: Make sure
the eyebolt and nut are aligned
properly so the motor assembly
can slide into the body tube.
Step 2 – Insert Motor Tube Assembly into Body Tube
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 body tube to ensure a snug fit. Sand the
centering rings if necessary. When you are satisfied with the fit, spread some epoxy on
the inside of the body tube and slide the forward centering ring of the motor assembly
into the body tube.
Make sure you have the motor assembly facing the right way!
Spread some more epoxy on the inside edge of
the body tube before sliding the rear centering
ring into the body tube. Continue sliding the
assembly inside the body tube until the aft end
of the motor tube is even 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.
1/2” Exposed
1” Exposed
Forward Ring Hole
Fin Tang
Ensure rings are clear of the fin slots
