Pipsqueak re-start- Frank's big 23" span pylon racer (.049 size)

[Frank v B]

Covering the stab and elevator (or any solid surface)

Again, bottom first, top second.

Trick: when covering something like a solid stab, tack 3 sides and leave a short side undone.  The reason: this way air can escape.  Work your way from one short side (tip) and seal the film as you work your way up.  Work the iron from side to side while working your way to the other tip (end left open).  Do not remove the iron from the surface.  This way air will never be trapped.  When you get to the opposite tip, seal around the corner.

If you trap an air bubble, prick a hole with the tip of a #11 blade at one end of the bubble.  Push the air out with your thumb first, then with the iron, working towards the hole so air can leak out.

Where the covering goes around a curved surface like at the tip, cut a dozen slits in the edge covering and use the iron to attach it.

The second side is done the same way, but when you cut the slits around the corners at the tip, cut the new slits in-between the ones you cut for the bottom covering.  This way raw balsa wood will never show.

Photo 84- bottom side covered, edge trimmed.  Slits cut in the curved surface at the tip.
Photo 85- doing the second (top) side
Photo 86- slits cut in the covering of the tip.  The slits cut in the middle of the bottom side.
Photo 88- elevator bottom covered.
Photo 89- finished stab.

Frank

[Frank v B]

How to do a hinge with covering
Covering the fin and rudder.

This is a solid surface like the stab so it is treated the same way.

The rudder will be hinged using the covering material.  The principle is to have a bit of covering showing at the hinge point when covering the first side, then having the film of the second side fuse to itself at the single line.  If it does not fuse to itself it will eventually pull apart.

Prepping:
- leave the back edge of the fin square, not rounded.
- bevel the leading edge of the rudder at about 45 degrees with sandpaper on one side only

Covering:
step 1- cut one piece of covering the size of both the fin and the rudder.  Photo 90
step 2- flip the rudder onto the side of the fin so the trailing edge of the fin and the leading edge of the rudder are beside each other. Photo 91
Step 3- attach the film to the fin and wrap it around the rudder.  Carefully heat seal the hinge line to make sure it is attached. Photos 92, 93, 94, 95. 
Step 4- when attaching the second side, start at the leading edge of the fin and work your way towards the rudder.  When you get to the hinge line deflect the rudder fully and then attach the film to the hinge line and rudder. Photo 95
Step 5- trim and seal the edges. Done! photo 96, 97

Frank

[Frank v B]

Covering the fuse.

Order: bottom first, sides next and top last.

This plane has a sub-fin under the stab, so that was covered first.

The photos show the bottom done (first, photos 98, 99) and one side done (second).

This was treated like the approach for the stab.  The covering was place on top of the fuse side (clear plastic backing removed!), tacked at the front, pulled at the tail and tacked there.
Then starting at the nose, I moved the iron back and forth while working towards the tail.  Do not remove the iron from the covering while doing it so there is no chance to trap air.
To get rid of the balsa showing through the wing saddle, I installed a strip to cover the slits. Photo 03

Frank

[msatin]

Very nice Frank.
Perhaps you'll cover this (no pun intended) later, but how are your going to hinge the aileron? Same method as the rudder?
Also - when you were covering the wing, at what point did you cut the hole for the servo arm?

[Frank v B]

Mark,

Will make sure to describe the aileron hinging.  It is done after shrinking the wing covering.

It will be the same as the elevator.  I left the description out because I made a mistake.  I wanted to hinge the elevator the same way as the rudder but once the brain-fart set in I had the pieces covered and forgot to hinge it the way the rudder was hinged.

Mark- here is the added section on film hinges.

Hinging an in-set (barn door) aileron with film.  Requirement- the aileron must have a 45 degree bevel with the long edge on top (see photo 08).  The wing side of the hinge must be 90 degrees

Step 1- cut two strips of covering the length of the aileron and about 1" wide.  These will become the hinges.  See photo 07
Step 2- secure (heat) one strip to the aileron so the rest sticks up.  The glue side faces the aileron. See photo 08.  It shows the end of the aileron.  You can see the angle of the leading edge and the hinge film standing up from the leading edge.
Step 3- flip the aileron backwards so the top edge touches the wing.  The film strip will now point downward and on the trailing edge of the wing.  Hit it with heat and attach it.  See photo 09.  Sorry for the blurry photo.
Step 4- Attach the second strip on the top of the aileron only.  Do not attach it to the wing. See photo 10
Step 5- hold the aileron at full "down" deflection and attach the strip to the wing while holding full down deflection.  Start the heat at the hinge and work your way forward to the edge.  This way the covering shrinks before it attaches.  If you attach the wing end of the strip first and then shrink it (attach it) with heat, the hinge will be stressed and not allow full deflection. See photo 10.
Step 6- admire the cheapest hinging method.  No hinge gap so 100% performance.   See photo 11.

I have used this method on planes up to Speed 400 (Nooner).
It is especially terrific on thinner surfaces. (1/16").


Frank

[msatin]

Got it

[Frank v B]

So you laugh at my photography.  Look what I have to put up with.

This is the camera I use to take all the pictures for my posts.  This is what happens when you drop the point of a crowbar on the display.

That is not a viewfinder.  At best it is a view approximator   

Andy should have something to say.  He may even feel sorry for me.

Yes, Covid is getting to me.  Back to building!!

Frank

[Frank v B]

Small details:

Hatch pull- I make a hatch handle out of covering material.  It is attached the end of the hatch, fastened around the bottom.  The part sticking out is doubled onto itself and heat sealed.  It is thin and strong enough to overcome the pull of the hatch magnets. Photos 14 and 15

How to cut the covering on the stab.  I line everything up with a ruler.  Once the stab is square onto the fuselage, I pull it back about 1/4" (photo 16) and knife cut the covering top and bottom.  The reason, when it gets pushed up to the front of the slot the fuse will cover the cut exactly.  See photo 17

How to line up the stab-  I set the wing first and screw it in place.  Then slide the stab in the slot.  Eyeball it from the front to see if the stab lines up and is parallel to the wing.  If off, I open up the slot in the fuselage at the top of the low side of the stab to allow it to be lined up.  Then I put glue on the exposed balsa of the stab and the slot and slide it in.  The final adjustment to make it parallel to the wing is done by sticking a round toothpick on the bottom of the stab until it looks straight. See photo 18. The reason for the round toothpick is that allows for fine adjustment.  Just push it in further to raise the stab more.  Once the glue has dried, pull out the toothpick.
Note:  I don't fuss too much about the wing being totally square to the fuselage.  I am a happy man as long as the stab is parallel to the wing.

Fin and rudder.  I install these last because they have to be exactly square to the stab.  Next post.

Frank

[Frank v B]

How to make sure the fin/rudder are at right angles to the stabilizer...

Oh, that's how it is done!


Frank

[Frank v B]

Servo connections to wigglers:

On small planes I use 1/16 plywood horns but do the order in reverse:

1) cut horns out of 1/16" plywood and drill a hole for the pushrod.
ii) cut a slot in the moving surface (aileron, rudder, elevator) for the horn.
iii) center the servos
iv) cut the pushrods out of suitable wire material and make all the "Z" bends
v) center the moving surface.  I put a strip of balsa across the surface and clamp it on both sides.
vi) connect the pieces, add a dab of 5 minute epoxy to the slot and insert the horn.

When dry, it will automatically be perfectly neutral.

Frank

[Frank v B]

Done!!

For those eagle eyed readers of vintage, you may have spotted the streamline VECO wheels from the '60's.  Found them in my wheel collection.

Frank

[piker]

Nicely done, Frank!  And so quick!