WAC Corporal Model Rocket - Remixed

Introduction:

The WAC Corporal model was one of the first models I printed.  I printed, built, and flew it in one day and it was amazing and flew several times, until a tree ate it.

I went back to my evil lab and began work on a few things that I, personally, add or like with my builds.  There is absolutely nothing wrong with the original kit as-is.

Parts:

Things you get:

• Fin - Thickened to 3.18mm
• Fin Alignment Jig - Same as original but modified to accommodate the thicker fins
• Nosecone - The original's diameter was too small and after too much fiddling with it, I opted to simply use @cwbullet's Sapphire nosecone which fits better for my tubes
• Dorsal Greeble - I made this solid otherwise unmodified
• Launch Lug - simple and effective
• Motor Mount Tube with Retainer cap

Things you will need:

• BT-50 Body Tube - 305mm (12-in)
• BT-20 Motor Tube - 72mm (~2.83-in or 2-27/32")
• 12-in parachute
• CA Glue or 5-min epoxy (please don't use wood glue on plastic)
• CA Debonder - If you work with CA Glue and don't know about this, you should
• Motors - I suggest Estes B6-4 and C6-5.  The sim (see screenshot) has a couple others for you, but the C6-5 is a pretty aggressive motor for a park.
• Shock Cord - ~1270mm or 50-in.  Kevlar Kite string works pretty good
• Modeling Tools and Stuff- If you don't have these things, there's about 30,000 of videos on YouTube that can help you much better than I.  Wear Eye Protection

Build:

This is a highlight build guide and not meant to be instructions.  Dry assemble first and take your time to understand everything before you whip out the thin CA glue and start cussin'

• Glue the BT-20 sleeve inside the motor mount tube.  If you use CA glue, feed the sleeve in from the aft (threaded) end and move really fast.  The glue may give you as much as a full second before it grabs.  When it does, that's where your tube sleeve will be.  If you don't get it in all the way, cut off the excess and you should be good.  
   
• Grab your fin alignment jig and BT-50 body tube and with a pencil, mark where each fin will be glued.  If you're mad as a hatter, just send it and glue the fins now.  Just a thin bead along the surface to be glued to the body tube, and be careful not to glue the jig to your body tube, your fins, or your fingers

Not use the baffle…

• You can file down a little trough on the forward centering ring (furthest from the threaded end) of the motor mount tube so that your shock cord will sit flush and not cause a bump in the tube.  
   
• Tie a half-knot in one end of the shock cord
   
• Lay the shock cord though the cutout with about ½-in between the aft and forward centering rings, with the knot towards the aft end.  most of the shock cord should be on the forward end.  Glue the shock cord down.  When the glue is dry, tuck the remainder in the motor tube from the top
   
• With a stick, measure the distance between the forward and aft centering ring.  This is the distance you will need to put glue in the body tube.  Get gluing and don't get any in the motor tube.
   
• When the glue is dry, blow the shock cord from the aft end

Using the baffle…

For this, it's helpful to have an 18" wood dowel or equivalent 

• Tie the shock cord to the baffle and secure the knot with a drop of CA glue
   
• You need to get the baffle at least 125mm up from the aft end of the tube.  You need to glue this.  It is suggested that you use epoxy.
   
• Put epoxy inside the tube at around 125mm.  Smoosh it around
   
• Feed the shock cord into the body tube, followed by the baffle, trying to keep epoxy off the shock cord.  Use isopropyl alcohol to clean up any epoxy where you don't want it
   
• Push the baffle up past the epoxy line.
   
• Slather some more epoxy in the aft end of the body tube and push it up until the threads are even with the aft end of the body tube.
   
• Make sure the shock cord is coming out the forward end of the body tube
   
• Tie the end of the shock cord to the nose cone. 
   
• Secure your parachute to the shock cord
   
• Glue the dorsal greeble to the body tube.  Wherever it looks good.  I put mine in line with the fin, opposite the launch lug

Final Notes:

• Since this model does not have a thrust ring, you will need to add one to the end of the motor.  Using masking/painter's tape, build up a lip of tape about 1/16th of an inch thick. This thrust ring doesn't need to be very wide.  1/8-in wide should be enough to keep the motor from ripping though the body tube, but make sure before you light this candle.
   
• Always double-check the dimensions of the model against your tubes.  Estes tubes should work but other mfgs may have variances that will cause frustration or failure.
   
• Model Rocketry is a safe and enjoyable hobby for kids and adults when the NAR Safety Code is observed.  If you plan to fly this, please have some experience or do some homework on flying low-power rockets.  This is the way.
   
• I provide this model without warranty or guarantee of safety.  I have tried very hard to make this a workable builder's kit for you to enjoy but sometimes, I don't get everything right. Print, display, and launch at your own risk.  
   
• If you print this and put it on your desk at work, you're gonna be the coolest cat in your cube farm.  Enjoy the fame! 
   
• Message me if you have any questions.  I love talking about rockets and 3D printing!