FlatCat Boost/Glider Build, Part 6 - The Tail Section

The beauty of building a boost/glider is that one can construct any of the several sub-assemblies while waiting for the glue to dry on all the others.
This post deals with the FlatCat's tail section.
This particular design features a 3-piece assembly - one large rectangular horizontal stabilizer, and two vertical stabilizers.
The various pieces are cut from a sheet of 1/16" thick C-grain balsa stock .  The specified dimensions are quite simple to lay out.  As with all model rockets, paying attention to specified grain direction is  important.
Here are the freshly cut parts:



The next step is to shape sand the vertical stabs.  Since this build is strictly for sport flying, and not necessarily for high performance, I'm going with just rounding the leading and trailing edges, followed by surface smoothing with 400 grit.  I'm not going to do any sanding on the horizontal stab until the entire assembly is complete and attached to the fuselage.  This will prevent me from accidently rounding the edges of gluing surfaces.

Now, the vertical stabs can be glued to the edges atop the horizontal stab using the double glue joint technique. Must remember that they are to be orientated in the same direction! (I have to constantly remind myself of these kinds of things - senior moments, you understand). The model would still fly with one stab turned the wrong direction, but it would just LOOK stupid!

A handful of LEGO bricks helps keep things aligned and at a precise 90 degree angle. (Where's THAT in the Handbook of Model Rocketry?)

Once the assembly is dry, I can apply some light glue fillets to the inner side of the h/v stab joints for added strength.  With a glider, it's best to go easy with this, since excessive amounts of glue does tend to add more weight.

The final step for this sub-assembly is to sand the corners of the horizontal stab to match the vertical stab round-overs.  This is just an aesthetic touch that's not spelled out in the published plans.

Here's the completed assembly, all ready for gluing to the fuselage.

NAR 60 Year Reunion, Part 13 -More Fine Displays

Another one of the display tables held a large collection of early Canaroc model rocket kits.  This presentation was provided by Mr. Denis Lufkin (NAR 96987).

On yet another of the tables was a display by John Chatham of the SAI (Space Age Industries) model 'da Judge' mounted on a MMI style wood launcher.

SAI was also well-known back in the 60s and early 70s for their 'Hen Grenade' egg-lofter kit.

Right next to John's display was a small slide viewer provided by Tom Pastrick (NAR 2276)

where attendees could view pictures of early NARAMs.

NAR 60 Year Reunion, Part 12 - Vern Estes Takes The Stage....

The second speaker of the evening was Mr. Estes, who gave a nice talk on the early NARAMS and his history with them.

Amazingly, Vern has been to 58 of the 60 NARAMS!

During his speech, Vern stated that he wasn't sure if the first National Championship meet held in 1958 was actually called  NARAM-1.  He has never seen any documentation that specified that.

At that time, Bill Stine got up and approached the podium and handed Vern a piece of paper. We never heard what was in that document, but it might have held the answer. Perhaps we will find out at a later date.

On the humorous side, Vern was describing the early use of the standard NAR lead payload weight.

"That was before these were invented."  he said, holding up an egg!

At the end of his speech, Vern stated that he and Gleda were finding it increasingly difficult to travel across the country to attend model rocketry events.  He told the assembly that NARAM 60 will likely be the last one at which they would be present.

I can only speak for myself, but I am pretty sure that there was many a moist eye in the meeting hall following that announcement.

When he was finished with his talk, Vern left the podium to the accompaniment of an extended ovation from the attendees.....

FlatCat Boost/Glider Build, Part 5 - Some Mighty Fine Wing Assembly

Preparing the wing root edge for gluing…

The MRm instructions say to bevel the root edges.  This is done to provide a better gluing surface to join the two halves of the wing.   One can get by with eyeballing and free-hand sanding this bevel with a sanding block.  Being a careful modeler (yeah…right…), I like to be more precise.

I prop each wing half up to the prescribed dihedral angle – in this case – 2 inches root to tip, and sand the bevel with a vertically oriented sanding block.  It’s all about control, my friends.

TIP: Again it is wise to pay attention to which wing is being worked on, and sand the proper bevel angle.

ANOTHER TIP:  Use of a courser grit sandpaper is recommended here.  The idea is to produce a rougher gluing surface to better ‘grab’ the glue.

 Gluing up the wing…

 As pointed out in the MRm article, a double glue joint is used to join the two halves of the wing.

TIP: It's always wise to use a piece of waxed paper to lay the glued-up wing assembly on, otherwise the bench top becomes a permanent part of the wing.

The instructions say to prop each wing tip up to the specified 2 inches for the dihedral angle.  I prefer to perform this step by laying one wing flat on the table and propping the other wing tip up to 4 inches.  I also place a small weight on the ‘bench top wing’ as an extra measure to keep things from moving around. 
In my workshop, any item that just happens to be sitting around within reach gets pressed into service as a construction jig!

I'll let the assembly dry thoroughly before moving it.

Once the wings are dry a flat, wider gluing surface must be sanded into the bottom of the joint.  Again, courser paper should be used here to help the glue to grab better.

The wing assembly is now ready to attach to the fuselage.

NAR 60 Year Reunion, Part 11 - Another Interesting Display

Moving along to more of the display tables;

This tribute to Len Fehskens was set up by John and Wini Labreque.

The display was loaded with lots of photos, news clippings and meet awards.

Also displayed was a Starship Vincia model, Vincia kit, and original Vincia design sketches.

 

 

 

 

NAR 60 Year Reunion, Part 10 - A Few Words From Bill Stine

After being introduced by NAR president John Hochheimer, Bill Stine took the podium.

Bill related the story of the beginnings of the hobby of model rocketry, starting with how his father, G. Harry Stine, an engineer at White Sands , had published articles about the dangers of amateur rocketry. One of these articles came to the attention of Orville Carlisle, who had developed a small paper and balsa rocket powered by hand loaded solid propellant engines - the first model rockets as we know them today.  Orville sent some of his rockets and engines to Mr. Stine to test out.  The models turned out to be the solution to the 'Youth Rocketry Problem".
Bill went on to describe the formation of the first model rocket manufacturer, MMI, in 1958, and the founding of the Model Missiles Association, which later came to be known as the NAR, and the establishment of the Model Rocket Safety Code, which has been so important to the hobby.
He went on to describe a brief history of the first NAR sections in Denver and Colorado Springs, as well as the very first National Championship meets that came to be known as NARAM.

During his presentation, Bill made the statement that, in the 60 years since the beginning of model rocketry, over 500 million successful flights have been conducted! 

To help us wrap our heads around that large number, Bill asked everyone in the room to close their eyes.  He then began to pour some pellets into a metal bucket.  (I'm not sure whether they were pellets, beads, beans, or what.  My eyes were closed).
As he poured, Bill stated that the sound of each pellet hitting the bucket represented 100,000 successful model rocket flights. 
And there were a lot of pellets!

On a more amusing note, Bill held up an object in a small baggie.  It was a rubber grey nose cone that was used for the Aerobee Hi model rocket from MMI, the first commercially produced kit. 
Bill stated that this nose cone was given to him as a baby for him to chew on as a teething device.

Gives a whole new meaning to the phrase 'Cutting one's teeth on model rocketry', doesn't it?

FlatCat Boost/Glider Build, Part 4 - Let’s Rustle Us Up Some Glider Wings.

Ah, there’s nothing like a full-sized, fresh chunk of balsa wood – just waiting to be butchered!

Taking the easy measurements off of the plans, the first job is to mark out the FlatCat wings.  For accuracy I like to use a straight-edge reference block and a small drafting triangle to mark the 90 degree cut lines.

A little precision slicing with a straight-edge and the ‘Sword of Exact Zero’ (Ref. The LEGO Movie) to produce a pair of wing blanks. 

Once the wings are cut out, it’s time to mark them with the high point of the airfoil.  I’m placing it parallel with and approximately 30% chord length aft of the wing leading edge.  For those of you who aren't quite up  on wing terminology, chord length is merely the dimension from wing leading to trailing edge, analogous to a standard rocket fin root edge.

IMPORTANT TIP:  It is rather important to keep the wing pieces oriented for left and right sides!  I don’t want to end up with two of the same wing – then I'd be forced to build two FlatCats!

In reading up on the history of the FlatCat, I learned that many of the earlier versions were built with non-air-foiled wings.  Even the plans and article from which I am working here show the model minus an airfoil.  In the last paragraphs of the article, Mr. Stine suggests sanding in an airfoil to optimize glide trim and performance.  Since I’ve done that with all of my past B/Gs, this FLatCat build will be no exception.

A piece of masking tape is set along the high point line to serve as a stop, preventing that point from being sanding down while forming the airfoil.

Back in the day, when I was more interested in building gliders for competition, I would have taken the time to sand a slight taper from the wing root edges to the tip, but since this is a sport bird, I will forego that step.

 To start the trailing edge of the airfoil, I place the wing parallel to the edge of the workbench and set it back about an eighth of an inch and hold it there during sanding.  I allow this little bit of clearance since I don’t want to sand the trailing edge to a sharp knife edge, as doing so might compromise the strength of the wing.

Using a sanding block equipped with 200 grit paper, I then sand a bevel into the trailing edge of the wing.  Doing so defines the final thickness of the trailing edge. Courser sandpaper is used because the idea is to hog off a substantial amount of wood while forming the airfoil.

 Now, still using the 200 grit block, the area between the wing high point and trailing edge is carefully sanded to define a gentle tapering curve (See the following illustration).

 Next, the masking tape strip is moved to the other side (aft)of the high point line. 

Again, using the 200 grit block, a gentle curve gets sanded into the fore part of the wing.

The leading edge now gets rounded over - top and bottom.

Once all is said and done, the finished wing profile should look like this:

 The next step involves smoothing out the wing.  This is done by lightly going over the entire wing surface with progressively finer grit sanding blocks.  I don’t sand very aggressively here, as it’s all about smoothing rather than further shaping.  300-400 grit paper works well here. 

It also doesn’t hurt to go over the flat bottom surface of the wings with fine grit block to smooth them out as well.

Next post will cover the wing glue-up.