FRANK'S 1/2A F4U CORSAIR BUILD

[Andy Hoffer]

Rob,

re:"Port and Starboard wing sadles, LOL!"

Left and right is a direction.  Port and Starboard is an orientation... relative to the pointy end of a boat or an airplane.

Sorry to be picky and detailed.  Heck, Andy must be starting to rub off on me.  Oh no!

Frank

Bummer!!   

Andy

[Andy Hoffer]

Today's topic:
How to straighten a crooked wing
How to make symmetrical mistakes.. but not those ones!


Took out all the pins from the leading and trailing edges and guess what? a Crooked wing.... about 1/2" of wash-in.  Dangerous, unflyable.

Pinned the root of the wingtip section to the building board via a rubber band.  Used scrap trailing edge balsa to prop up the leading and trailing edge so root is at zero/zero.  Then propped up the trailing edge at the wing tip with a scrap piece of trailing edge balsa to give it about 1/4" wash-out (trailing edge higher than leading edge).  A total shift of about 3/4".  Cut and trimmed the top leading edge sheeting and glued it in place.  Held by the two rubber bands at the ends and pins in the middle.  When this dries, the wing should at least be straight.  Then I will install the bottom leading edge sheeting and pin it to the board again while it dries.

Whatever the result of this wing straightening, I will duplicate it on the other wing half.  At the covering stage I will be able to give it some more was-out by twisting the wing while it cools.

Sorry Bruce. No "T" pins. Note how I cut back on the pretty pink pins

Please see http://temac.ca/smf/index.php/topic,6455.msg41987.html#msg41987

If you insist on using "unmanly pins" you will get "unmanly curves" in your wings!  For heavens sake, heed the admonitions of our sagely CFI!! 

Andy

[BJROB]

Sorry Bruce.  No "T" pins.  Note how I cut back on the pretty pink pins

Frank ...its ok to use pins of colour as pink is just a colour

[Frank v B]

Back to work.......

Photo 28- shows the close-up of the port wing half.  The leading edge is closest to the camera.   The leading edge sheeting trick worked and the wing is now straight.  The bottom leading edge sheeting has not yet been done.  The photo shows the landing gear block in place (below the rectangular balsa doubler).  The original design was just the landing gear block sitting in between the two ribs with a plywood rib doubler on each rib.  Not enough, especially since I know who will be flying this thing.

Have added the balsa triangle re-inforcement at the leading edge to brace the landing gear.

Have added triangle braces at the trailing edge where it splits and the aileron starts.  Without braces, this would be a very weak area.

Photo 29 a close-up of the center section with all braces in place and drying.

Bruce, please note how large the photos open up when you click on them.   Just for you.  If you still have problems seeing them I will add a Braille setting.

[Frank v B]

Sheeting the center section.

It was very obvious that each wing bay had to be sheeted individually because of the compound curves.

The original plan was to put the top and bottom on at the same time and glue them from the trailing edge up to the high point in the rib (spar), let it dry, then draw it together at the front and glue it in place.  Problem was the clamps kept sliding off the leading edge.  Ended up glueing the entire piece onto the wing (top and bottom), then wrapping it with green tape to hold it in place.  There are 3 wraps of tape to hold it in place.  The first wrap would not stick because I had to soak the balsa to allow it to bend.  Tape does not like moisture.

Photo 30- view from the bottom of the wing.  You can see the landing gear blocks in place here.  Bruce: the photo is a little blurry.  It should normalize after two beers.

Photo 31- two sides done and allowed to dry.  The one clamp is to keep the sheeting flat on the rib.

Photo 32- My new favourite piece of woodworking equipment- Roger Mason's carbide stick.  It makes sanding so fast, accurate and easy.  It has a fine and course end... just like the man himself.

[Frank v B]

Now the tedious centre sheeting.  Doing a section at a time, top and bottom at the same time.  Wet the wood, spread the glue, hold the wood, wrap tape around the wing to make it hold.  There are three rows of tape on this section with 3 loops each.  Each loop was pulled progressively tighter to make it follow the contours of the ribs.

The wing servo plates were installed, the servo wires fed through each rib.  The servo was glued in place with 5 minute epoxy.  Yep, I tested them first.  Only the arms will protrude through the bottom of the plate.

The servos were repurposed from Michael's black Spitfire wing he sold at the TEMAC Swap meet.  Michael, your plane lives on.  Thank you for signing the Aviation Donor Card.

Photo 33 top view of the wing sheeting just completed.  The servo is glued in place, the servo arm slot has been cut.

Photo 34- bottom view of the wing- shows the servo slot.

[Andy Hoffer]

Hey @Frank v B, 

You should just keep going with the green tape.  You've almost got the whole wing covered! 

Your good friend,

Andy

[Michael]

Interesting, in that the grain of the sheeting is not lengthwise.

[bweaver]

Re:  Interesting, in that the grain of the sheeting is not lengthwise.

Simply put, that's Frank.  I am sure he will have a really good reason for it though.  I can wait to hear it. 

[Frank v B]

Michael- re: "Interesting, in that the grain of the sheeting is not lengthwise."

I only made one small modification in the leading edge to reduce the cut pieces by four.  Enough cutting and fitting already.  See photo instructions.



Bruce:
re: "I can wait to hear it.  "

Please do not read the above....but hold your breath and keep waiting!


Frank (who else?)

[Michael]

I didn't criticize; I simply noticed something unusual.

[Frank v B]

Hey Andy!!
re:"You should just keep going with the green tape.  You've almost got the whole wing covered!  "

Brilliant!

Frank

[Andy Hoffer]

Hey Andy!!
re:"You should just keep going with the green tape.  You've almost got the whole wing covered!  "

Brilliant!

Frank

Thanks Frank.  Like you, I am more than just a pretty face!! 

Andy

[piker]

Interesting, in that the grain of the sheeting is not lengthwise.

I agree it looks odd as it's not the usual way, but I assume it's because those areas of the wing require the sheeting to follow compound curves as the inverted gull shape created curves span-wise.  The curve span-wise is likely tighter than cord-wise... so it's easier to align the gain that way.

While I'm here... I'll just add that the build looks AWESOME Frank!

[Michael]

Interesting, in that the grain of the sheeting is not lengthwise.

I agree it looks odd as it's not the usual way, but I assume it's because those areas of the wing require the sheeting to follow compound curves as the inverted gull shape created curves span-wise.  The curve span-wise is likely tighter than cord-wise... so it's easier to align the gain that way.

While I'm here... I'll just add that the build looks AWESOME Frank!

Now, that's a good explanation!