How to Build a B-29
#53
Thread Starter
My Feedback: (7)
Aileron and flap servo mounting:
Set servo on 1/32" ply before gluing gussets and placing servo screws. Then servo will be mounted perfectly when ply is removed
Servo mounting frame glued into wing under sheeting. The removable servo fixture screws to this frame
Both servo mounting fixture and aileron horn flush with sheeting
Du-Bro #366 control horns for flaps
Make sure control horn for the flap and the servo horn are perfectly aligned so there is no load on flap servo in the UP position
#57
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My Feedback: (7)
Make another jig of scrap 3/32" balsa that fits exactly in the top of the well, butting nicely against ribs on the side, front and rear spars on ends
Then, once you get that perfect fit, trace and cut the real thing out of 1/4" BALSA and glue it to the top sheets and all the aforementioned sides. This will help spread the load of imperfect landings to the whole retract well, heck the entire inner wing
(see previous video of Mark's landing)
Last edited by kram; 12-21-2015 at 04:14 PM.
#61
Thread Starter
My Feedback: (7)
Trim and smooth the surface at center-wing for the ply doublers.
Epoxy doubler in place
Custom carve and glue some little plywood wedges to fill the gaps between between doubler and bottom spars
Obviously, this joint needs to be really strong for such a long-winged bird
#63
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Center bottom spar joined and 1/2" balsa fit and epoxied to spar doubler
Added air tanks.
I will cut opening in top wing from first rib to first rib and front to back spar to provide access to brake controller, retract valve and other stuff
Glued hardwood wedges to fill gaps twixt spars and spar doubler
Robart hinge pockets (#315) EIGHT per flap in wing TE
1/8" Robart hinges (#307) will glue into flap LE
#64
Thread Starter
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To pinpoint location for control horns and servo mounting, I cut wood screw tips and mount them in mounting holes, then press bottom sheeting down gently to mark the cut-out locations
I use T-pins to line up the wing sheeting before applying CA
Sheeting is simple after all the work I did and the ribs, etc, to make them perfect gluing contacts. Having servos, control horns and gear completed prior to sheeting makes both the sheeting and the hardware installation faster and more accurate
#66
Thread Starter
My Feedback: (7)
Bottom of center wing with the four 4-40 screws that hold the wing tips to the plane
I use two 1/32" ply rib caps, then slide the wing tips in place with epoxy on the tip side and center side of the 1/32" caps. Slide the tips tightly into place and lock them, then there will be no gaps and the assembled wing will look like one seamless piece.
Indentation marked with an arrow was made by tapping hinge rod at wing tip. I'll make a pocket there. This is so hinge rod can be accessed to remove the aileron without major surgery
#67
Thread Starter
My Feedback: (7)
Time to add gap strips using 3/32" hard balsa
Great (and easy) way to smooth flow over the airfoil and improve aileron response in-flight
To ensure there is plenty of room under the gap strip for aileron LE to move freely, make sure the aileron LE is rounded precisely and the hinge rod is smack-dab in the center of the semi-circle that is the LE
#68
Thread Starter
My Feedback: (7)
Topside, center, cut access pocket that extends to first ribs, right and left, and front to rear spar.
A LOT of "goodies" will live here
I laminate the bottom of this pocket with 1/4" balsa to strengthen. Storage, handling, assembly and disassembly of the wing commonly requires lifting from center-bottom of the wing
#69
Thread Starter
My Feedback: (7)
I know some of you are thinking: "Dwayne can't build this fast. He's not even retired!"
"Mark must've stockpiled these photos and he's doling them out too fast"
Nope, this is real speed.
It is possible that having built several B-29's gives him a Spider Sense of where he's going every step of the way
Dang! I wish I had that!
Mark
"Mark must've stockpiled these photos and he's doling them out too fast"
Nope, this is real speed.
It is possible that having built several B-29's gives him a Spider Sense of where he's going every step of the way
Dang! I wish I had that!
Mark
#70
You must have a HIGH tolerance for CA fumes to go like this ! hahahahh
It would cost an extra $1000.00 dollars to build this plane with Odorless CA
I always forget to look in the building room when I swing by Dwaynes flyin....
It would cost an extra $1000.00 dollars to build this plane with Odorless CA
I always forget to look in the building room when I swing by Dwaynes flyin....
#73
Thread Starter
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Nacelle building and engine mounting starts with parts that are not on Don Smith plans
First step is making firewalls by tracing cowls on 1/4" aircraft ply
Carefully mark: Dead Center Lines, both horizontal and vertical. These will be critical later for alignment
I mount Saito .91 engines at 40 degrees from horizontal. That makes starting and adjusting easy
Last edited by kram; 12-29-2015 at 08:33 PM.
#74
Thread Starter
My Feedback: (7)
Second piece (there will be 4 pieces for each nacelle) is the front flange of the nacelle that is right behind the firewall and the firewall bolts to it. As you can see, 24 oz fuel tank slides right through it, so can be easily accessed and serviced
Make four identical flanges of 1/4" aircraft ply
Last edited by kram; 12-28-2015 at 06:59 PM.
#75
Thread Starter
My Feedback: (7)
Four key parts of the firewall:
1) flange for front of nacelle
2) smaller flange that glues to the back of #1 to give nacelle planking something to hold on to. Made of light ply and exactly 1/8" smaller than #1 all the way around
3) 1/4" aircraft ply firewall
4) 1/8" aircraft ply cowl ring. Bolts on to firewall to hold cowl on and allow easy accessibilty