This is a Covid Re-start. Built the fuse years ago and installed a 28mm in runner which will be too big. Will downsize to a 24mm in runner. Bought one for $5.00 at the Kitchener Swap meet. The plans were published in Radio Control modeller waaayyy back in 1967.
This plane has ailerons and elevator, rudder and.... it has wheels! The instructions caution you not to hand launch it unless you have a 40 mph headwind. This could be a one-flight beauty.
Work completed before the re-start-:
- fuse built and sanded
- motor installed
- all balsa parts cut out and ready to assemble (Stab, elevators, rudder, fin, ribs)
Last night I found the plans, found the stick balsa and started the wing. Just pinned the trailing edge together.
The photo shows the state it was in this morning.
This will have the Orangeville EF-1 guys shaking in their boots.... with laughter. ;) ;D
Frank
That looks great, Frank! Wow.
Started the wing.
Photo 37- stack-sanded the ribs and marked the top spar groove with a magic marker so they all orient the same way.
Photo 38- placed 4 ribs on the bottom main spar and glued them in place and let it dry.
Photo 39- tail feathers cut out of balsa.
Frank
More wing work:
Photo 47- ready for the top spar.
Photo 48- installed the top spar and about to add a false leading edge. I slipped about 20 rubber bands on it, added glue to the front of each rib and installed it. The rubber bands were stretched to hold it in place.
Photo 49- leading edge in place with all the rubber bands stretched.
Frank
The wing continued.
Two adjustments:
The trailing edge was in 2 parts to handle the ailerons. The 1/8" thick balsa at the back end of the ribs was higher than trailing edge stock. This had to be shaved down to be flush with the trailing edge stock.
Photo 50- Put masking tape on the ribs and trailing edge. This is to protect the ribs. Then tried the razor plane. Mixed results.
Photo 51- Try 2- with Roger's DuraGrit sanding bar. WOW! much faster and easier.
Photo 52- Adding the main leading edge ahead of the thinner false leading edge. It is pinned to the board to keep the leading edge straight.
Frank
Motor choice:
The motor I slipped in was a 28mm out-runner helicopter, high KV motor (Photo 54). The motor I wanted to change it to was a 24mm Ammo inrunner (photo 53) to save weight.
Now I am totally confussed. The 28mm motor weighs 2.5 oz, the 24mm in-runner weighs 3.5oz. Counter-intuitive.
Looks like I will be keeping the larger but lighter motor. Weight is an issue with such a small wing. The output is about equal (300 plus watts)
Frank
- Making the elevator halves. I keep them together until the hardwood joiner is glued in and dry. See photo 58. After the glue dries, I will separate them.
- installing the bottom fuse at the back 1/3 only until the servos are installed and the pushrod slots are cut. See photo 59
Note, there is a hatch on the bottom of the nose held in place with 2 magnets. The entire fuse bottom behind the leading edge of the wing is solid. Made the wing removable. the plans shows it glued in place.
Frank
Electronics decision:
1) Opted for two aileron servos glued into the wing. The other options were bellcranks, wire inside a sleeve or torque rods but each would require cutting into ribs and fussy alignments.
Before installing them in the wing there are 3 things:
i) test that the servos work. Done via a GreatHobbies Servo tester.
ii) center the servo arms. Done with the tester. It as a "center" button.
iii) put dental floss on any servo cases not held together with 4 screws. Two wraps of dental floss and one drop of glue on the knot. I have had them come apart!!
2) Two HS55's for rudder and aileron. They have 4 screws so no flossing required. ;D
Will post a photo once I figure out why it is refusing to attach. (insubordination?, Hoffer influence?)
Frank
Very cool plane, Frank!
Photo 82- wing servos installed. Note the details i) servos glued in place They will last longer than the plane, ii) servo extensions installed. The connections are wrapped with dental floss and one drop of glue. iii) cut slots in the bottom ribs, slipped the wire in place, added 1/16 balsa to close the gap with a drop of glue. After it dries I will cut it and sand it flush. iv) the LE wing dowels. Pointed skewers. I slide them back, put ink on the tip, hold the wing in place and slide the dowel forward. It marks where to drill the hole in the fuse former. Once done, I put in new stronger dowels.
Photo 83- The servo rails in place for the elevator and rudder servo. Screws can now be installed. The two pins hold the tri-stock in place on the landing gear mount.
Frank
All the glue joints cured overnight. The first time the plane has been assembled.
Looks weird. The wing seems short for the fuse length but then this is a minimal pylon racer. Have you ever seen a photo of the full size Cassutt Formula 1 Racer with its small wing (last photo)?
On take-off, V1 will probably be close to terminal velocity. ;D
Frank
Cute as a button!
Thanks Piker!
Covering: a step by step :"how-to cover a model airplane". Use this as notes so you can concentrate on Michaels on-line seminar later on.
Note: Everyone has their own way of doing things. My way is just one option.
Step 1- cover the corners where there have to be cuts in the covering (photos 71,72,73)
Covering the wing.
Guide:
- do the bottom of the wing first. One half at a time. If you have a true flat bottom wing on a small plane it can be one piece. The reason the bottom is done first is because the edge from the top covering wraps around the bottom. You won't see the edge.
- Peel the backing film and lay the covering on the wing half.
- Tack the corners. touch the heat gun at at the 4 corners to keep it in place. I touch the center trailing edge first to adhere the covering about the size of a dime, then lightly pull the film on the outboard trailing edge and tack it down with heat. Now the film is in place and won't move. Lightly pull and tack down the other two corners.
- do the aileron area- Cut two 45 degree angles in the covering (photo 74) and attach it to the trailing edge, then the sides (photo 75). Now you know why the first step was to cover the inside corners.
- attach the entire perimeter but do the tip last.
- cover the tip. Hold the wingtip covering between your thumb and forefinger. Pull the covering until the wing is at an angle. You are using gravity to stretch the film (photo 78). While the covering is not touching the wood, lightly heat the covering so it stretches, then adhere it to the wood. In most cases the tip will be wrinkle-free.
- cut the excess covering. A trick to cutting. I use a brand new #11 blade and start about half inch from one end (photo 76). Cut to the end. Then the second cut to the left (photo 77) and remove it. The reason: this way you do not have to hold it while cutting accurately. A lot faster and more accurate than starting at an edge.
Important. Do not stretch the covering until the entire wing is covered. The reason: On a wing, you need to handle both sides (top and bottom) at the same time or the structure can and will warp. The lighter the structure, the more important this is.
Do the other 3 panels in the same way.
Declare victory!!
Frank
The other 3 panels.
The only extra trick to point out is when finishing the wingtip covering. Photo 80 shows the 1/4" overlap of the top covering. I put about 10 cuts in the radius. They are visible in the photo. Then run the covering iron over it from back to front (trailing edge to leading edge). This is so that the seams are overlapping downwind so an edge can't be caught by the wind and be peeled back.
Photos 81 (top of wing) and 82 (bottom of wing) show the finished wing before heat shrinking the film.
Frank
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
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
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
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?
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. 8) 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
Got it
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 8)
Andy should have something to say. He may even feel sorry for me. ;D
Yes, Covid is getting to me. Back to building!!
Frank
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
How to make sure the fin/rudder are at right angles to the stabilizer...
Oh, that's how it is done!
Frank
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
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
Nicely done, Frank! And so quick!