Monday, October 12, 2015

Aileron mechanism rework

I must say thank you to Alan of the Yando Goat for his plans updates (posted on the airchair yahoo group).  His additional two small parts to the wing make the aileron actuation look possible.  I knocked out the two parts within about an hour of waking up and had them installed a few minutes later.  The control line passes over the rib nicely.  Awesome.

The control rod looks like it can clear the strut attachment now.  However, the control horn is in the wrong spot by a few inches, but I see Alan moved its location over slightly to compensate.  Wish I had found all this before putting holes in the LONG aileron leading edge tube; think I can put a bolt in each of the old holes and it is safe.

Before you say anything, I am going to replace the washer holding the quick link in place with a larger one that fits better.  And I obviously still have to switch the masking tape for fiberglass and epoxy to hold the aileron slide tube guides in place.

Thanks to Yando Goat!  Now go watch one of his awesome videos for encouragement:
https://www.youtube.com/watch?v=uAw93maL1tg

Saturday, October 10, 2015

Aileron and flap hinging

It took some combination of the original drawings and the extended wing to find locations for all the hinge points, but they're set now.  I also took the liberty of setting the flap and aileron lengths within the three inches of extended span.  Beyond that, the process is stock.  The trailing edge tube gets a hole that is measured a surface-distance away from the top of the tube; an easy way to get this is to use a long straight-edge touching the top of the leading and trailing tubes and sliding this back and forth to leave a line.  From there, the surface distance gives a mark for the hinge bolt.

Root before hinging

Root after flap hinge installed

Typical wing control surface hinge.

The aileron control surfaces also have a control horn attached to the leading edge tube.  This is a simple mechanical arrangement for actuation, but seems to be quite stiff with the horn near the center hinge.   

The picture shown here has red control line holding it up in position for the photo, so just ignore that.  I have to get more line to have enough for the whole wing control rigging.

Where the control rod attaches to the horn is also the same area for the attachment of the wing strut tube.  Another Goat builder said this tube will interfere with the control rod, and it certainly appears that way.  I'd like to find some pictures of Alan's build and see how he did it.

For visual interest, I cut four foam ribs to build up the flap in chord and see how it looks at full size.  The flap is about 2/3 the span of the aileron, but it's still quite large. 

In none of the Goat versions are the flaps actuated.  Instead, they are held fixed by the control rigging between the tail and the wing, but that comes later.  First I have to make two dozen more ribs, which I am planning to do on my CNC, then add carbon rods and fiberglass tape.  For now, it's just cool to get a feel for the size of the surface and see how the surfaces move.

I also added the last braces for the root rib, and riveted them, admitting the wing won't need to go back down on the surface plate (i.e. concrete floor) anymore.  On that note, I also riveted the wing tip handle in place.  Last tasks for this wing are:
  • tip rib bending
  • tip rib bracing
  • bend the last standard wing rib that goes near the tip also
  • glass the ribs to the leading and trailing edges
  • aileron trailing edge tube bending
  • fit aileron trailing edge tube into the control horn sub-assembly
  • make a dozen or more foam ribs for the control surfaces
  • glass the control surface ribs in place with a carbon rod capstrip
  • control line guide tubes
  • control line pulley to turn downward to the aileron linkage in the fuselage
  • leading edge foam sheeting
  • a few odds & ends, like flipping the orientation of some bolts and replacing one compression strut that has some extra holes in it
After that whole list, I can jump to the other wing and simply copy all the measurements.  I'm better at duplication than making modifications to existing measurements.  The other wing should go quickly as long as I get to a point of cranking out wing ribs quickly ... that's what I got hung up on before.

Maybe I'll assemble Goat in the driveway tomorrow to examine the strut to aileron linkage interference, and to open up the garage for sweeping up all the aluminum shaving debris.  It should be nice to have some space to run the CNC as well.

Sunday, October 4, 2015

Aileron control linkages

Did a bit more work today since I am on a roll.

The aileron control linkage sub-assembly is now complete, awaiting a hinged aileron tube to give it something to actuate.  Nice to knock out some parts like this that come together quickly and give a sense of accomplishment while making later assembly go quicker as well.

I remember reading another Goat build that switched to torsion rods for the aileron actuation.  So far I'm building the stock pull-pull arrangement and will see if it looks okay before making changes.

This photo looks a bit awkward, but shows the attachment of the aileron actuator mechanism sub-assembly into the wing.   The attachment to the compression strut just needs to be epoxy and glass and it's ready for installation of the pullies. 

One step closer...

Saturday, October 3, 2015

Rainy day wing work

Apparently I don't like hot weather for building.  On the other hand, a nor'easter make great building weather in the garage!

Spent a few nights this weekend bending ribs.  Finally have enough for one wing half, so they're now taped on to see what it looks like.  I'm much more accustomed to building model airplanes, so it's wild to build ribs at this size.

The root rib is installed and is getting its braces temporarily installed. 

Before the ribs go on, I need to build the ailerons and flaps.  Since I stretched the wing a dozen inches, the hinge locations will be moved slightly, and I have to stare at it a bit before committing.
The third dimension on the wing really changes how it looks.  I grabbed some peelply from the basement to make a mental image of what it might look like covered.  Cool.

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