samparfitt

My Feedback: (43)

John,
Send me the airline tickets plus two thirty old blond sheilas are my 'maids'!

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Wings (cont)

After a two week flyin road trip to Florida, I'm back to the B-26.

I finished drilling/tapering the bracket and attaching them to the inner wing spar.
I cut some 3/32" thick ply as a backer for the outer wings aluminum bar so the bar would align with the bracket and screwed the bar with the ply to the outer ply spar.
Everything was dry fitted and then the outer wing spar was cut from the inner wing spar.
This insures the outer wings will align with the inner wing.
Two sets of brackets were used plus new aluminum bars were cut longer to insure a rigid wing.
A metal tab will also be used to screw the bottom of the outer wing to the inner wing to insure that the outer wing doesn't flex up, since the bar/bracket is along the top of the wing.

I pinned the 3/8" square hardwood to the plans and epoxied the spar and the ribs for the inner wing. Before gluing this together, I checked the alignment of all the tops/LE/TE ribs to each other with a straight edge plus insured all TE tabs rested on the table (one rib had to me moved back).
The entire inner wing will be with hardwood stringers and epoxied to insure a sturdy/no flex wing.

samparfitt

My Feedback: (43)

videos:
Some good videos that I found on youtube.

Walk around:
http://www.youtube.com/watch?v=ZhKWaY62X0E

============

5 part video:
(about 10 minutes, each)

part 1:
http://www.youtube.com/watch?v=tv7SV...eature=related

part 2:
http://www.youtube.com/watch?NR=1&v=b5iif3m2dpI

part 3:
http://www.youtube.com/watch?NR=1&v=1A_PsBEmbmM

part 4:
http://www.youtube.com/watch?NR=1&v=AutOvlMPzKU

part 5:
http://www.youtube.com/watch?NR=1&v=KAjFSBalmIs

Should get back to the 'build' in a few days.
While the weather is still good (and before winter sets in), I've been busy removing and re-siding my daughter's house plus Fall weather brings chores to be done around my house.

samparfitt

My Feedback: (43)

Wings (cont)

Center wing (cont)

As mentioned, previously, the 3/8" (main) and 1/4" square spars (front/ TE) are hardwood and were epoxied to the ribs.
Two (plus a small sliver of a third) 3/32" thick balsa were glued using carpenters glue, edge to edge, after the edges were sanded straight and taped together. The sheet was then sanded and cut to fit from the main spar to the TE spar and epoxied in place.
Next was another sheet from the main spar to the front spar half way to the LE.
I had some really hard balsa so I figured it was a good sheeting material for the center wing.

at-6 texan

Hello Sam apologizes for the trouble and ot. but I could maybe help me . I could lend a hand to find some thread where we talk about the rolling of aluminum. I ask 'cause I know you did this technique to the P-47. thk and soon

samparfitt

My Feedback: (43)

AT-6,
The aluminum application starts at Post # 100 at:

http://www.rcuniverse.com/forum/m_80..._4/key_/tm.htm

samparfitt

My Feedback: (43)

Wings (cont)


inner wing (cont)

The right half was dry fitted.
As with the left side, a razor saw was used to cut the outer spar from the inner spar.
I epoxied the back wing mounting plate incorrectly: fortunately, epoxy works like a rusty bolt: some heat made the epoxy soft enough to use a razor saw to cut the plate free without any damage.
To insure the two W-1 ribs aligned with each other, I first epoxied them together.
The bottom 3/8" square spar was then pinned to the plans, the left side of the wing was raised to get the two main spars to align with each other.
Ribs were then epoxied in place and then the top sheeting was epoxied, using the same procedure as for the left side.

samparfitt

My Feedback: (43)

wing (cont)

outer wings

I just noticed that there is no dihedral in the wings: probably didn't help the full size without it!
The bottom of the wing tapers up and the top side is, virtually, flat.
A 1/4" square balsa spar is pinned to the plans and the ribs are dry fitted.
The two 3/8" square hardwood spars were cut off the ends of the center wing and. also, dry fitted.
The hardwood and main ply spar were extended an additional rib for added strength. Rib R-11 was also re-cut as aircraft ply. The wing tip is also extended an additional 3 inches so another rib was cut.
Each outer wing will be, individually, built while attached to the center wing to insure a perfect alignment.

at-6 texan

many thk Sam

samparfitt

My Feedback: (43)

Wing (cont)

Outer wing (cont)

The ribs were epoxied around the main spar and carpenters glue for the rest of the ribs.
All 1/4" square balsa spars were glued to the ribs using carpenters glue.
While still on the plans, I sheeted the top using 3/32" thick balsa sheet from the main spar to the TE.
I tacked a 1/8" thick balsa along the TE of the aileron area to get the correct overhang of the top sheeting.
The sheeting in front of the flap was applied separately for ease of measurements.
The sheeting hangs out over the flap so I CA'ed a 1/64" thick by 3/8" wide ply to the edge of the balsa sheet and sanded a 45 degree angle. The ply, when CA is applied on a flat surface, makes the TE perfectly straight, stiffens the balsa sheeting (since it over hangs the TE) and reduces hanger rash.
I put a straight edge along the center and outer wing and there is about a 3/16" gap where the two wings join: I'm attributing this to the washout that is said to be in the risers on the outer ribs.

samparfitt

My Feedback: (43)

wing (cont)

inner wing (cont)
The front and rear mounting plates were epoxied to the wing.
The center TE was epoxied to the ribs.
All remaining 1/4" square hardwood spars were epoxied to the ribs.
An additional 1/4" square slot was cut on the LE of the ribs and a 1/4" square hardwood was epoxied to the ribs. This hardwood, along with the LE sheet will make the LE very rigid.

Outer wing (cont)
A slot was also cut on the LE of each rib on the outer wing and a 1/4" square balsa was glued using carpenters glue.
1/8" thick balsa sheeting then was rough cut and glued to the LE of the ribs.
The LE was sanded to align with the ribs and the final sheeting was glued from the main spar to the LE.

samparfitt

My Feedback: (43)

Wing (cont)

Center wing (cont)

I cut and sanded some 1/8" thick aircraft ply for the LE of the center wing.
I took extra time to sand the edges at an angle to match the curve of the ribs as sanding aircraft ply after it's on the wing will be difficult.
I epoxied them to the 1/4" square hardwood spar on the front of the ribs.
This will give me a good, flex resistant center wing.
As with the P-61, two engines and main gear connected to the center wing is going to get a lot of abuse!
I haven't check but some of those spars probably have to be trimmed for tanks, engines, gear, etc so having aircraft ply and hardwood will keep the structural integrity.

Outer wing (cont)
The top sheeting is complete.
Sheer webbing will be next to prevent flexing.

samparfitt

My Feedback: (43)

Wing (cont)

Right wing

First, all parts were dry fitted to the center wing.
Then the first four ribs and associated parts were epoxied.
Next, the rest of the ribs were glued using carpenters glue.
And, finally, part of the top sheeting was glued to the wing.

Previously, I must have checked incorrectly as a long straight edge now shows all three wings to be perfectly flat along the top sheeting.

invertmast

My Feedback: (23)

Looking good sam. I believe i'll be starting mine late spring next year, after i get my first F-14 kit laid up. Do you happen to have any good websites showing different schemes, squadrons, and other info like that? I've got a friend who's grand-father flew B-26's in WWII that past away a few years ago, that I feel it would be fitting to do my build up in his scheme

ram3500-RCU

My Feedback: (221)

Nice progress Sam.

samparfitt

My Feedback: (43)

I find that squadron signals and osprey usually have books on the plane that I build.
They usually only cost 13-20 bucks, each, so cost is low.
Googling the plane also produces web sites such as :
http://www.google.com/search?q=b-26+...Gcfe0QHzj-3KBA

invertmast

My Feedback: (23)

sam,
Thanks for the info. Next time you are fiddling through your docs, could you see if any of them have a photo of "hell's kitchen", it is S/N 42-95756, B/N 77

samparfitt

My Feedback: (43)

Thomas,
Didn't see any hell's kitchens.

Thanks, Gary.

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Wing (cont)

Outer wing (cont)
As with the left wing, a 1/4" square balsa strip was cut/glued into the LE of the ribs and then 1/8" thick balsa capped the rib edges for extra strength. Carpenters glue dries best is only a thin layer is present so I use an acid brush to remove all the excess glue. A heat gun also helps drying time, especially, during the winter when the temperature isn't as warm as during the summer.
The remaining top sheeting was glued from the main spar to the LE.
A piece of balsa with 1/64" thick ply CA'ed to the balsa was cut/glued for the flap TE area.

Outer wing:
Sheeting from the main spar to the LE was epoxied to the left half of the wing.
Masking tape works well to hold the front edge of the balsa sheeting to the LE when clamps won't fit.
The intricate area for the flaps/nacelle area was cut out of one piece of balsa with the appropriate 1/64" thick ply CA'ed to the TE and epoxied to the ribs.
I wish that I had more of this really hard 3/32" thick balsa for the wings: this balsa is stronger than most of the lite ply that I have seen.

Thunderbolt47

My Feedback: (8)

Looking good Sam. I've always wanted to build a Marauder. Are we going to see this a Joe Nall 2012?

Kelly

samparfitt

My Feedback: (43)

Thanks Kelly,
I always like to get fix flights on my warbirds before taking them to a meet and Nall is too early in the season, at least up North, to accomplish that.

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Wing (cont)

Center wing (cont)
The rest of the top sheeting was epoxied to the right front and right back of the wing.
F-6A/8A's (flap outline) were epoxied on the TE.
Holes were punched through the top sheeting for location of wing mount holes (before I forget and cover up the bottom!).
Sheer webbing will probably be next (I can still, slightly, flex the wing).
Each flap will be getting their own servo.

samparfitt

My Feedback: (43)

Miscellaneous:

Since it was 70 degrees today, besides yard work, I cut all the large chucks of balsa that are needed for wing tips, LE, stab tips and LE, elevator tips, nacelles rear contours plus I cut some insulation foam to support the fuse in the inverted position.
I picked up some old balsa at a meet for 5 bucks each so I cleaned them up and cut them for all the needed parts.

samparfitt

My Feedback: (43)

Wings (cont)

outer wings (cont)
Sheer webbing was added to the main spars, as well as to the wing connecting bar spar, of the outer wings.

Flaps and ailerons.

Some 3/32" thick balsa was cut for the bottoms of the flaps and ailerons.
1/64" thick X3/8" wide ply was CA'ed to the TE bottoms of the flaps and ailerons sheeting (a square is used to hold the ply to the sheeting on a flat surface, while the CA is applied).
The top LE and TE of the flaps and the TE of the ailerons were sanded to match the angle of the respective ribs.

Flaps
inner/outer flaps of the set of four flaps:
Ribs were CA'ed to the bottom sheeting of the flaps and then 3/32" thick balsa was glued to the trailing side of the ribs using carpenters glue.

inner flaps:
Blocks of balsa then was tacked CA'ed to the leading side of the flaps and sanded to get a rounded edge to match the flap sheeting. The blocks were then removed so, later, control horns can be inserted in the flaps.

Ailerons:
1/8" thick balsa sheeting was CA'ed to the LE of the bottom sheeting of the ailerons.
Individual ribs are being cut and CA'ed to the bottom and LE sheeting of the ailerons.

samparfitt

My Feedback: (43)

elevators (cont)

Balsa blocks glued to the tips of the elevators, power sanded and then hand sanded to close to final shape.

samparfitt

My Feedback: (43)

Wings (cont)

The flaps were sanded to fit the wings so I can, next, install hardware.
The anti-rotation pins were also epoxied to the outer wings using 1/4" diameter aluminum dowel stock from home depot.
Two metal straps were also screwed to the bottom spars where the wings join to insure no UP flexing while in flight. Sheet metal screws hold the straps to the outer wings and 6X32 blind nuts were secured to the inner wing for the machine threaded bolts.
Large clamps used to secure the wings together while pins/straps were installed.
Servo extension tubes were also dry fitted into the wings. Some extra holes were cut into two more outer ribs since I will be installing the aileron servos midway along the ailerons.

samparfitt

My Feedback: (43)

Wings (cont)

Flaps (cont)

As seen in the first picture that I took of a B-26 at the air force museum, the hinges are visible along the bottom of the flap so I made mine the same way (going scale on this versus my usual method of pin hinges).
Note: the museum keeps it dark so it's difficult to get good pictures (at least with my camera!).
I got some G-10 from Frank while at Monster planes so I'll be using it for the main support hinge (wing side).
I cut two support hinges out of G-10 per hinge and used some aircraft ply for the flap side hinge.
I had to use my band saw with a 1/8" blade to cut the G-10 as a scroll saw blade dulled in about two minutes. I 'doubled up' the sheet to cut two at once: masking tape had to be applied continuously, as each part was cut to keep the two sheets together.
Holes were drilled in the base of the G-10 to give the epoxied some surface area to adhere to.
The flap side hinge is just a full flap rib with a hinge profile added to it.
The main support hinge is like a large apostrophe. The G-10 is about 1/16" thick so I sandwiched the 1/8" thick flap ply hinge between the two main support hinges and a 4/40 hex head screw with a locking bolt to secure them.
A piece of 1/8" thick ply was also added between the main hinges on the wing side to keep them aligned and then two triangular pieces of balsa block was epoxied on both sides to make the hinge strong.
Since the main hinge goes through part of the flap, in the UP position, I had to cut a 1/4" wide slot in the flap sheeting for proper movement of the hinge. After the block balsa LE was epoxied to the flap, I also had to elongate the slot into the LE for the hinge.
I added an extra rib on both sides of the slot to strengthen the area.
I also added an extra rib to each end of the flap for 'just in case': sometimes additional sanding of the ends of the flaps are needed to get proper fit and the extra rib gives me a 'buffer'.
The flap side was first epoxied. After that dried, the wing side hinge was dry fitted while the flap was aligned to the top of the wing and 1/16" thick ply was used as spacers between the flap and wing: the parts on the wing side were then epoxied into place insuring a correct flap alignment.

The first hinge set was put in so they were parallel to the ribs: this resulted in a small bind in the open position. The next hinge set was installed so the hinge was perpendicular to the LE of the flap but this moved the flap, in the open position, to one side about an 1/8" (or less) which causes it to contact the sides of the wing. The original bind is minor so I went back to installing the hinges parallel to the ribs.

The control horn was then epoxied into the flap: this was also 1/8" thick aircraft ply, which matched the flap ribs but has the protrusion to connect the control rod. Dubro heavy duty ball links are being used for the control horn.
Obviously, with this setup, the linkage will be 'all internal'. Having the point of rotation located below the flap, versus a pin hinge on the LE, gives my a lot more leverage distance between the hinge point and the control horn point.

ram3500-RCU

My Feedback: (221)

Looks good Sam. I admire your skills. BTW, nice dust collection system.