Discovery™ Assembly ©2007 MadCow Rocketry™ 3
Ensureringsareclearofthenslots
Step 4 – Fin Assembly
Testteachofthensintotheprecutnslots.Thenshouldseatrmlyagainstthe
motortube-sandeachnifnecessary.Whenyouaresatisedwiththet,applysome
epoxytotheendofthentangthatwillcontactthemotortubeaswellasthenroot
that will contact the body tube. Also, spread a thin layer of epoxy on each side of the
ntang.Slidethenintoplaceandcheckthealignment.Continuerecheckingthen
alignment until you are sure the epoxy has set. Clean any excess epoxy from around the
njoint.Repeatfortheremainingns.Next,applyepoxylletstobothsidesofeachn.
Carefullysmooththeepoxylletswithyourngerbeforetheepoxysets.Alloweachllet
tosetbeforerotatingtheairframeforthenextllet.
Step 5 – Launch Lug Attachment
Mark the CG point along the launch lug line you made in the previous step. Make sure
you measure the CG point from the tip of the nose cone and NOT the end of the body
tube. Apply a small amount of epoxy on the launch lug line about ¾” long on the CG
mark. Press one of the launch lugs into the epoxy and ensure that it is aligned with the
launchluglinepreviouslydrawnonthebodytube.Youcansitedownthetubeandlook
through the launch lug to make sure it is straight. Similarly epoxy the second launch lug
about 1/2” from the aft end of the body tube. Site down both launch lugs and make sure
they are both aligned. If you have a ¼” launch rod, you can use this to ensure that both
lugs are aligned properly.
Step 6 – Forward Section Assembly
Insert the eyebolt through the hole in the center of the bulkhead and secure using the
washer and nut. IMPORTANT: Apply some epoxy to the nut and eyebolt threads
to ensure the nut doesn’t come loose later. Apply some epoxy to the inside of the
coupler and push the bulkhead in so there is about a 1/8” to ¼” of coupler exposed.
Aftertheepoxyhasset,applyalletofepoxyaroundtheinsideedgeofthecoupler
bulkheadjoint.
Next mark the coupler 2” from the forward edge. Apply some epoxy to the inside of the
forward body tube section and slide the coupler up to the mark. There should be 3”
of coupler exposed. Make sure the coupler is straight and the body tubes are aligned
properly when they are assembled later.
over the forward centering ring) 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
ofthebodytube.It’sagoodideatotesttanineachslotherebeforetheepoxysets.
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.
Usingadoorjamorsmallsectionof
anglestock,pencilalinehalfwaybetweentwoofthensthatextendsfromthefrontto
the back of the body tube. This line will be used later to align the launch lugs.
