SeamusG

I need to chill a bit before I proceed. Need to rethink how I want the wing / fuse to look. I really like your treatment of the wing bolt plate on the wing bottom. Also the leading edge block. Also, the DB aileron does not extend to the fuse side whereas the KC does. The use of fillets and the aileron approach needs some more think time. The DB also uses fillets around the tail feathers while the KC uses 90 degree butt joints.

There are so many similarities between the Killer Chaos & Dirty Birdy kits while enough differences that really differentiate the two planes.

SeamusG

Jeff - you mentioned that you had used some number of small pieces of balsa during the shaping of the fillets - think it was in your build thread. Were these used as ribs between the 3/32 ply base and the fuse side? Did you consider using foam? I've got remnants from a combat plane's foam wings that might easily be shaped into a fillet and then covered with micro-balloons paste. Just thinkin' out loud.

AllTheGoodNamesAreTaken

My Feedback: (180)

Old age is setting in... I forgot to mention that tri-stock is used between the fuse sides and the fillet ply - then blended in with epoxy/micro balloons. I dont see why you couldn't use foam, but I dont see the weight savings over balsa.

SeamusG

Gotta little work done. The elevator halves have been connected with a 1/8" wire yoke. The stab was installed on the fuse using a Harry Higley approach. The fin was installed with a 1/8" locating dowel thru the fuse into the bottom near the leading edge. The fuse sides were straightened a bit with 1/4 x 3/8 stock (on the inside of the fuse - should be far enough towards the rear to clear the control rods). The fin post was epoxied and shimmed with 1/32" ply to ensure a straight sides.

pic 1 - 1/8" rod fitted into 9/64" holes - allows wiggle room to make up for any errors in bending the yoke
pic 2 - yoke recessed into the leading edge of the elevators
pic 3 - where there were once 4 there are now 3 Robart hinge points per elevator. Holes were filled with finishing resing/micro-balloons putty and new holes were located, drilled and beveled
pic 4 - yoke epoxied and taped to ensure all is straight when dry
pic 5 - actually 3a - the holes have been filled with putty
pic 6 - finished and very straight elevator pair. Hinge line is great.
pic 7 - what else do ya do with 2 corn muffin boxes and 4 cans of Campbell's soup? The front of the stab was shimmed with 1/64" ply to ensure that both wing and stab had identical incidence.

Let me know if you want more details on Harry Higley's approach for attaching stab to ensure that stab is parallel to wings.

SeamusG

pic 1 - stab and fin epoxied
pic 2 - intersection of stab leading edge and the fuse - a bit of resin putty will make it disappear
pic 3/4 - the right angle never lies
pic 5 - just admiring the end result
pic 6 - separators to straighten fuse sides under the stab
pic 7 - fin post +2 1/32" ply shims +30-min epoxy + 3 clamps = flush / straight fuse rear
pic 8/9 - em, had some 1/4" tri-stock. Seeing what a wood fillet would look like. Messing with so 3/4" tri-stock over the wing.
pic 10 - Robart incidence angle
pic 11 - resin putty stuff ...

SeamusG

Left something out - NOW Ican locate the elevator &rudder horn positions. Then hard points will be added in support of the horns. Fiberglass cloth can be added in support of the exposed wire yoke. And FINALLY, I can fabricate the control rods and drill the necessary holes in the fuse so I can glue the darn fuse bottom in place. Whew.

Then it will be time to finish the ailerons - IFI can figure out why they keep warping - and Ihaven't even tried to straighten them yet 'cause they were straight when Ibought 'em. Grumble grumble grumble ...

SeamusG

Progress has taken a step backwards - need to reconstruct elevators. Oh well. Guess it's an example of "if it can go wrong it will" ...

You all have heard of Murphy's Laws? Well how about O'Shaughnessy's Law - ya, law - singular. "Murphy was an optimist!".

SeamusG

It's like deja vu all over again

SeamusG

The new elevators have been shaped and fitted to the stab. All hinge point holes have been located & drilled. I like the seams on both ends and the hinge line. Hey, 3rd time's the charm. Yea, I remember saying that the 2nd time was the charm - live-n-learn.

I've located the horns for both elevators and the rudder. The distance between the horn stantion and the hinge line is 3/4". On the elevators the hole is also 3/4" from the inner edge of the elevator. On the rudder the hole is 1/2"from the bottom edge of the rudder. I did this as it locates the stantion in between the bottom edge and the 5/32" wire of the tailwheel.

I'd like any comments about their locations.

pic 1/3 - alignment of the new elevators.
pic 4 - left elevator (right is identical)
pic 5 - elevator down &rudder left
pic 6 - elevator &rudder neutral
pic 7 - elevator up &rudder right

Btw - the stantion bolts will be cut down after configuring the control rods, servo arm, Rx &Tx travel setup.

PS - I'm planning on pinning the area around the supports &then saturating with thin CA. I've seen others (BWI think does it) use hardwood hardpoint inserts rather than relying on the balsa of the control surface. In my case, the rudder is actually 3 layers with Titebond as glue. The elevators started life as 1/2" medium weight balsa stock.

PPS - I'm also considering adding lightening holes in both the rudder and both elevators. Em, or is that removing lightening holes? I was thinking of two ovals on the elevators spaced between the hinge points - I'm only using 3 hinge points for the elevators. Maybe 3 holes in the rudder.

SeamusG

The tail feathers have been glued and the seams have been hit with some finishing resin / micro-balloon putty. Ireally need to come up with some decent sanding jigs for use on inside corners.

Next on the agenda are the ailerons. I bought some 1/2" x 1 1/2" x 36" tapered stock. I left the 1/2" at the leading edge and cut the chord to plan dimensions. The wing's trailing edge needed a bit of truing up with a 24" sanding bar &80 grip paper. The fiberglass tape plus finishing resin finish kicked the trailing edge out of "straightness". I also needed to adjust the wing tip extensions a bit 'cause I blew the measurements on one of the sides. Not a big deal when ya have a bunch of balsa scrap, Titebond and clamps.

Before rounding over the aileron leading edges the Robart hinge point holes were marked and drilled. No problemo'. The aileron tips got a little up close and personal attention to get the tip gap nice and straight. After the holes were drilled, expanded with a tapering bit on the dremel and fitted there was still a bit of a gap because there was a slight bend in the aileron stock. Ihave a 48" aluminum "L" stock with one outside edge covered with 80 grit paper. With the this laid over the edge of the table I ran the aileron's LEover the paper until everything was flat. A lines 3/8" from the LEwere made on both sides and then sanded to a hyperbola shape. The final fit was very good.

Only thing left on to do with the ailerons is to shape the wing tip extensions to match to profile of the ailerons. Just gotta remember to position the ailerons in a flight neutral position BEFOREI shape them.

pic 1/2 - putty applied to tail feather joints
pic 3 - joints sanded
pic 4/5 - making up for poor measuring skills
pic 6/8 - checking end gaps before shaping
pic 9/11 - post shaping alignment

w8ye

My Feedback: (16)

The best kit builder is the one that can recover from mistakes and warps.

You are doing good

SeamusG

He, he - just as long as I don't use transparent covering [8D]

Balsa is so forgiving and easy to fabricate into whatever ya need.

My major problem is that I keep changing my mind!

SeamusG

I'm happy to say that it's really taking shape. It looks like an aeroplane inspite of my best efforts.

The ailerons were clamped in place using a couple of pieces of aileron stock. Kept things very stable & aligned with the wing's airfoil. Blue painter's tape was used to protect surfaces that were already at their final shape. This allowed me to get pretty aggressive with 80 grit with little concern of hacking into good wood. After shaping the top and bottom surfaces Imarked the angle of the tip's trailing edge to match the wing plans. Everything was sanded to shape. Not bad, not bad at all.

I was so close to having a plane sitting on my bench rather than a bunch of parts I couldn't help myself. I installed the landing gear and used gravity to hold the canopy in place. This has gotta have the WIDESTlanding gear stance that I've every seen on a 60-sized plane. Is it possible to drag a tip?

One item Ihave to address - the left landing gear axle is about 1/4" ahead of the right landing gear axle. Gotta take care but it shouldn't be too difficult to adjust. Where's my BFH005?

pic 1 - keeping the aileron in line while shaping the tip's trailing edge
pic 2 - luv that blue tape
pic 3 - tape telltales show that enough has been removed and the final shape has been marked in pencil
pic 4 - the other side
pic 5/6 - rough sanded tip trailing edges (need 120 / 220 to finish) - a little filler will be required
pic 7 - just enjoying my 1st view of the wing
pic 8/12 - hey, it's starting to take shape - yea baby!

Note: the Elmer's glue with wood fibers tends to dry dark. Check the color of the excess glue on top of the main spar. Maybe Titebond would have been a bit lighter in color. OR if I'd cleaned up after myself - but wait - I'm not using transparent covering - NEVERMIND.

Btw - some early comments made during the cowl buildup suggested a more streamlined cowl bottom may look better. Now that I can see the whole picture I can appreciate that sentiment.

SeamusG

I took the opportunity to check the wing and stab incidence. Being proped up at the tail the wing is at +1/4 degrees and the stab is at -1/4 degree - total:the wing is +1/2 degree with the stab at 0 degrees - just what the plans ask for.

Also, the lateral balance is spot on without the engine/mount, tank, Rx, bat. Shows that there is no "build"imbalance.

Next step is to install everything and set up the radio, throws, etc. before tearing apart for covering.

SeamusG

Last night I kicked back on the sofa with a pad of paper and put a ToDo list together. Basic stuff but there were a couple of redo items. These are:

[*]Reposition the wing in the saddle so that the trailing edge is snug with the rear of the wing saddle.[*]Re-sheet the bottom of the wing bounded by the leading edge, the landing gear mount, the main spar and the 2nd rib. Sanding the wing flat reduced the thickness of this area to maybe 1/32". Oops. No big deal.[/list]The holes drilled for the wing bolts needed to be filled and redrilled. The bottom mounting plate was removed using a very sharp wood chisel. Small pieces carefully removed resulted in a pretty decent finish. A little 80 grit / 120 grit and things were flat and the fiberglass was preserved. The same chisel (3/8" wide)was used in conjunction with a Xacto saw opened up the mounting holes to squares of 3/8". Some scrap balsa was sanded and glued into the holes. Probably stronger than the original soft balsa block.

Broken Wings

My Feedback: (20)

She's lookin PRETTY GOOD!!!! I like it!

SeamusG

Mistakes give you opportunities to try something new ...

The wing mount holes and bottom plate have been redrilled and replaced. I had some spare 1/4-20 nylon bolts. Isharpened the ends of 2 to rounded points. The pointed ends were cut to a length of about 3/4". The wing was aligned and marked with a tape measure pinned to the bottom of the fin post. The 1/4-20 ends were screwed into the threaded holes in the fuse mounting plates with the points exposed about 1/8". The wing was repositioned using the marks and then the trailing edge was pushed down onto the exposed points. With these marks as guides new holes were drilled (incrementally from 1/8" to 1/4") using a 90 angle to ensure that the holes were vertical with respect to the bottom plate. New screws easily threaded into the mounts. The alignment was rechecked - spot on. Practice makes (im)perfect.

A new bottom plate was fabricated out of 1/8" std. ply with rounded corners. The hole locations were carefully transferred from the wing to the plate. A relief seam was cut down the center on the underside of the plate to allow it to bend with the taper of the wing. 30-minute epoxy was applied and everything was clamped. Initial alignment was kept using the 1/4" drill bit shaft until the clamps quit squirming around. After the epoxy set the holes were dosed with thin CA. After a bit the holes were cleared out with the 1/4" drill bit (by hand of course). The end result is more asthetically appealing with no stress on the wing mount from the leading edge. And the wide gap between the trailing edge and the fuse has been eliminated. Not bad.

The landing gear has been adjusted using a bit of muscle and a vice - now both axles now measure the same with respect to the wing's leading edge.

The hole on the wing bottom has been framed and there's some 3/32"balsa sheet draped over a bottle to establish a gentle curve that matches the wing's profile. After it dries - it gets shaped, glued and pinned.

Too bad our club's "IBuilt It" 2009 competition judging is next Tuesday evening. Ain't gonna get this done in time - oh well ...

pic 1/2 - the nylon spikes (Vlad the Impaler would have been proud)
pic 3 - realignment
pic 4 - telltale spots for the new holes.
pic 5/6 - the wing mounted - front is not stressed - a good thing
pic 7 - the framework - probably overkill but ya just never know

w8ye

My Feedback: (16)

Take it in there anyway.

That's going to be a smooth flyer

SeamusG

Em, wonder if "in the bones" counts?

Just put a finger through another part of the wing sheeting. I'm seriously considering .5 oz glass reinforcement for all sheeting. A fellow club member is doing a one off "scale" pylon racer that is fully sheeted and covered with .5 oz glass. I had the privilege of letting my fingers do the walking over the wing and fuse. Awful fine. He shared his recipe with me. Just not sure that I'm ready for paint as key form of covering.

w8ye

My Feedback: (16)

I doubt if it counts but the guys will like seeing it.

vertical grimmace

My Feedback: (1)

Just so you know, this is such a wonderful flying aircraft. One of the best. It is hard to describe really. Once you get used to it, it will make you a better pilot. I lost mine last summer afer the stab came off. I should have reinforced it better. I flew that Kaos really hard though.

Broken Wings

My Feedback: (20)

Are we there yet?

SeamusG

Hey BW - I was bustin' butt to finish the Chaos before Jan 4th - my club's building contest for 2010. Since I missed it I've chilled and the Chaos is takin' a breather. It'll be a week or so before I attack it again.

SeamusG

I'm still workin' on the Chaos. Been doin' some covering schemes. Here's what I came up with.

I'm using Ultracote's Pearl Purple, Pearl Dark Yellow, Pearl Red, Lime Green and White. Should either be popular or alienating - nothing in between.

Just playing around with different bottom colors. Green would make things easier and just may look better in the air.

SeamusG

Now that I know the limitations of the BETAupload utility (blowing up IE& Firefox) I'll try to successfully update the thread with some more pics.

Fuel proofing has been completed!I used Finishing Resin undiluted applied thinly with an acid brush to the engine compartment and the tank bay. The were smooth to the touch before - but after the FRraised the nap of the wood - gonna need a bit of knock-off sanding. Not a biggie.

Wing details of the wing saddle and the left-handed-noblewinder that fills in the bottom of the wing just behind the bottom hatch (whew) got addressed - or at least -started. I used a putty made of FRand micro-balloons - pretty dry texture for the wing saddle. 1st, the top of the wing was covered in wax paper. Tried to pull tight but things magically loosen up when you're not looking. With the wing protected I laid in a peak-like line of putty along the fuse's wing saddle. The wing was then carefully fitted into the front former and then pressed straight down onto the saddle. The nylon screws were then inserted and tightened. I used a painters spatula to create a nice concave seam along the wing saddle. Leftover putty was put on a piece of wax paper and me-n-the-paper went upstairs for a while.

I kept track of the leftover putty over the next hour to an hour and a half. When it had set up to a very firm but not hard texture I went back to the dungeon to release the wing from the saddle. After it was released I used an old razor blade and cut the squeege from the inside and outside of the saddle leaving just a bit that can be sanded flush after it completely cures.

pic 1/4 - fuel proofing proof
pic 5/9 - wing covered in wax paper and temporarily fitted to the saddle to check the fit.
pic 10/12 - putty applied and wing tightened