Estes k-11 WAC Corporal clone...

[Mugs914]

The "most underrated Estes kit" thread got me thinking about my old favorite, the k-11 WAC Corporal. As I said in the other thread, I always had at least one in the fleet and it really was my go-to rocket. It flew at every launch.

I'm starting on a clone of the old Estes version and thought I'd post the build, though it truth there isn't all that much building required. It was a very simple kit.



This will be a true clone of the old kit including the incorrect fin airfoil and use the launch lug to represent the conduit on the rocket body, but I think I'll skip the "make two slits in the body tube and thread the rubber band through" method of shock cord attachment. It never seemed to last that long back in the day...

I have all the parts required on the bench with the exception of the really long launch lugs, and they have been ordered. I have a couple of ideas on how to approach the shock cord issue, one involves kevlar thread and the launch lug/conduit, but I'll have to see how that looks in reality!

Planning on cutting fins when I get home tonight, we'll see if that particular plan survives the evening...

 

[T-Rex]

Was my first model rocket that actually flew. Built a clone that flys great in the back yard on 13mm motors.
Enjoy the trip down the lane......

 

[TangoJuliet]

FYI - For a Kevlar Shock Cord on LPR, I've had success filing a notch in the outside of the 18mm Thrust Ring and tying the #100 Kevlar around it. The notch allows the Thrust Ring to still fit inside of a BT-20 (or equivalent). I also try to keep the Kevlar inside the BT and add 1/8" Elastic for the rest of the Shock Cord.

 

[Mugs914]

A bit of progress on the WAC:

First pic shows the basic parts. The engine block is already glued into the tube. Fins are 1/16", the washers on the lower left are the nose weight.


One of the fins after sanding the airfoil. Like I said before, this is a clone of the old Estes kit so the fin airfoil was sanded as per the plan with beveled edges. (The real WAC fins had a convex airfoil.)


I sanded one fin, glued it on and sanded the next fin while the first dried. I tried to get a pic of the airfoil...


...but this one shows the beveled edges a bit better.


After a few rounds of sand and glue, the basic rocket was done.


Here it is with it's big brother (Semroc 1/10 scale kit).


Still have the launch lug and shock cord to do, but the way I'm planning to anchor the shock cord requires the launch lug, and I am still waiting on my Erockets order with the long lugs.

My idea is to drill a small hole in the tube right where the launch lug fillet will be. A kevlar thread will be passed through the hole and the end on the outside bit will be knotted and buried in epoxy alongside the launch lug. The k-11 kit used balsa strips on the sides of the launch lug (to simulate the WAC's external conduit), so the kevlar will be hidden.

As you said T-Rex, this has been a fun trip down the lane! It is quite a bit smaller than I remember; I think they were bigger when I was 10...:wink:

 

[TangoJuliet]

Your bevels look great! And you're right, they were bigger when we were smaller. :sad:

 

[Mugs914]

Postman dropped off my launch lugs this morning so there will be some progress pics soon...

Well, unless I get distracted by the new nosecones that were also in the box and wind up starting a new project!

 

[T-Rex]

Can't argue the 'bigger when we were smaller' thing.... This thread got me to thinking about the original I built.... Ninth grade, ROTC instructor said we could have any kit in the catalog under $X & he would pay for it. I don't recall putting the taper on the fins, probably just rounded the leading edge. I painted mine with Testor's spray white, and Testor's metallic blue brush paint. Wasn't smart enough to realize that one could use hardware store paints, thought it had to be "model paint".

 

[Mugs914]

To be honest, Of all the Estes WACs I've built over the decades this is the first one I've ever actually beveled the fins the way the plans say. I always just rounded the edges too.

This is also the first time I have used the wood strips along the launch lug/conduit. It is interesting to me that none of the old facecards seem to have the wood strips either.

It is funny what you said about "model paint" Terry, I thought the same thing when I was a kid! Usually Testors brush paints for me since it was what I had on hand. Some interesting color choices as well; one of my WACS ended up in pale yellow with red fins and nosecone. Looked like the McDonaldland space program...

 

[Mugs914]

Well, construction is done. Nothing left now but filling, sanding (ad nausium), then primer and paint.

Here are some more pics:

First is the launch lug cut to length, tapered at the ends and glued in place.


Next is the shock cord installation I was talking about. A hole was drilled along side the launch lug and the kevlar cord threaded through. The kevlar is quite a bit bigger than required for this little thing, but it is what I had on hand.


The cord was glued down to the tube where it would be buried in the lug fillet and covered by the wood strips.


Speaking of the wood strips...


While that was drying, I tacked the weights to the nose cone and drilled out the base of the balsa cone.


The hole was then filled with epoxy. When the epoxy set to the rubbery stage I threaded the screw eye into it and allowed it to cure completely.


Last thing was to get a start on sanding the strips on the launch lug. Still some detail sanding left to do and then finshing.


This has really been a flashback for me and it has been fun to finally build one the way Estes intended. I have enough pieces left to do another one; may be it will have to be done the way we really used to do them!

 

[Incongruent]

Nice build.

Also, I love the composition in your profile picture.

 

[T-Rex]

Looks good Mike!

 

[TangoJuliet]

Very, very well done! :clap: Your 10 year old self would be proud. :wink:

 

[Mugs914]

Thanks guys!

Got the first coat of primer applied. Not as good as I hoped, but not as bad as I expected! May need another touch of filler in a couple of places but I think a good sanding should take care of most of it.