PointMagu

My Feedback: (11)

It’s been reported that Global’s Wacky Waco is a poor quality kit. No one discredits however, it’s flying qualities. In fact, there is a documented report of this design having a successful landing after a catastrophic failure of half the eppanage! As there aren’t many biplane kits out there under $50.00,(eBAY or elsewhere) I decided to buy it and see for myself. Here then, are my thoughts and observations on building this airplane:

Opening the box, everything is well laid out. Plans are rolled and all hardware is neatly packaged. Cabanes are stamped aluminum, pre-bent and ready to install. Landing gear legs are 1/8” bent aluminum. The wheel pants are essentially worthless. By reshaping the forward fuselage, the 2 halves of the vacuum formed cowling may be glued together to form a continuous unit and fiber glassing made much easier. This reshaping will facilitate installing the cowling over the engine mount. Apply a layer of 6oz. glass cloth around the rear, inside diameter of the cowl for secure attachment.

The photo instruction manual shows the tail feathers going together first so I started actual construction there.

If you own a pair of Midwest’s Balsa Cutters, this task goes quickly and accurately. Punch the die-cut parts as shown and dry assemble over the plans. First thing you’ll notice is that as you place these parts, the angles just don’t line up. Gaps abound everywhere. This is easily overcome by having gap-filling CA and activator on hand. I chose to use thin HandiBond CA as the primary adhesive then made fillets of thick CA at each joint.

Once you have both vertical and horizontals done along with rudder and elevator, block sand each smooth. Any remaining gaps should be filled at this time.

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PointMagu

My Feedback: (11)

The fuselage lamination is very straightforward with a few suggestions. Get several weights. This is a long fuselage and to prevent warping as the epoxy cures, having plenty of weights on hand will make things a lot easier. Also, the plans show open areas on the ply cores beneath the cockpit area. Once laminated with the outer balsa sides, these open areas create “pockets” that are very susceptible to cracking. My suggestion is to add stringers of 3/16” balsa along the inside seam lines of the 1st laminate then flip the assembly over and attach the other balsa side. This will give the long center balsa filler pieces something to attach to. You’ll soon see that as you add each piece to be laminated, long gaps result due to the balsa not being milled evenly. The length of the center filler is also short by about 1-1/2”. Scrap will be required to finish it out. Mix your 30 min epoxy with a few drops of isopropyl alcohol to make brushing easier and to make your adhesive go further. This is a large fuselage and it has 3 primary laminations to glue! Spackling makes short work of all the gaps once everything has cured.
At this time, you may wish to change the manner in which servos are mounted for the rudder and elevator. I cut 2 access holes for standard Futaba servos in the rear area of the fuselage. You can reference the plans for proper location of this modification,(your radio gear may be different). Servo wires are routed through an outer nyrod tube, slit lengthwise to clear the connectors, attached to the finished fuselage side. The weight that this modification adds to the tail can easily be offset by adding additional weight up front, if necessary. The servo connectors can then be inserted into the wing center and routed to the receiver.

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PointMagu

My Feedback: (11)

An important note: You may find that once the fuselage has been laminated, the vertical stab may not fit in between the balsa sides as shown on the plans! The only recourse you have is to sand down the tail enough to get the stab situated as shown. This also holds true for the filler piece directly behind the cockpit.

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PointMagu

My Feedback: (11)

Another approach to the fuselage is to saw the nose off just foreword of the “U” shaped plywood landing gear plate. This allows the addition of a contoured firewall epoxied perpendicular to the laminated profile with triangle gussets glued behind for additional support. This is an old ukie construction technique that lends itself to this project. I’ve never had much trust in 1/8” laminated light ply for a firewall nor as a motor mount! The kit includes pre-shaped bulkheads to mount the cowling and fuel tank but only for the port side. There are 2 of these that the instructions show being laminated together. Instead, use these as templates for your custom-cut firewall. By making this modification, you will have build the mount out far enough to get the engine thrust washer out beyond the cowling. You will need to measure the engine that you plan on mounting in order to get an accurate measurement out to that thrust plate. Even with the extended arms of your mount, the engine may set too far astern to clear the cutout on the front of the cowl. A simple laminate of several ¼” aircraft plywood pieces drilled and bolted to the main firewall should suffice in getting proper propeller clearance. Two 3/16” holes may be drilled into the fuselage with doweling inserted as “pins” secured with 30 min. epoxy for added strength. The motor mount can then be bolted to the extension, blind nuts installed with throttle access and fuel lines drilled. Remember that IF you chose this method, the cowling MUST be reinforced with fiber glass for rigidity! Otherwise, stick to the plans and trust the designers.

Block sand it all and set aside

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PointMagu

My Feedback: (11)

Wing construction mirrors the tail group. Gaps will need attention as will the top wing center section. Once assembled, trimming and some carving of the plywood ribs is required to get proper clearance for all the parts to fit properly.

I decided upon building lower wing panels 1st. The construction is simple and very straightforward. I used lead weights rather than pinning my parts to the work surface.
The 20-1/2” trailing edge stock needs to be reduced significantly to contour shape prior to installing the top and bottom trailing edges. I knocked this down with a small razor plane followed up with 220 grit sandpaper. Be very careful to get the cabane ribs vertical! Once sheeted, the struts need these ribs to be perfect at 90 degrees to the wing surface.
Another point: When knocking down the trailing edge, try to make both panels even. Once inserted into the fuselage, if the TE’s are uneven, the wing appears to have “twist”. That is, the 2 panels do not line up evenly on either side of the profile. If you have offset like I have, you can modify the sandwiched ribs that are glued to the inboard W-3 rib slightly to compensate for this twist. Also, be cautious when gluing the spars to the bottom wing inboard ribs. Once completed, you will need to remove that portion of the rib between the top and bottom spar. This is the area where the center ply main brace is inserted and epoxied.


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mrbigg

My Feedback: (21)

i didn't know they still made this kit. keep the pics coming.

PointMagu

My Feedback: (11)

Even though the panels build quickly, they are incredibly strong utilizing spruce spars and 3/32” sheeting along with a hefty ½” square leading edge. Each of the 4 panels do require significant carving and sanding to finish. Be prepared!
Aileron construction is quick and easy. Using that Midwest Balsa Cutter makes this job a snap. Use the plans to make your 1st aileron. Then, cover it with waxed paper and build the 2nd one over the 1st. This insures even sizing. Building over the plans proved not to produce consistent results.

You may opt to build the top wing in 1 piece as others have reported doing. I chose to follow the manual and join them at the center section. Primarily, I did not have the material to produce a 1-piece assembly so I followed the instructions. Clamping the 2 halves together is essential to providing a solid joint. Remove excess epoxy before it sets up with alcohol. This saves effort later on.

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PointMagu

My Feedback: (11)

The center cabane assembly is complicated but not impossible. However, IF you follow the very vague instructions, you won’t be able to mount your top wing so be forewarned! First, measure the solid wedge that is to mount between the aluminum inner-planes,(struts). You’ll find that the block is about 2” wider than the opening you just built into the bottom of the top wing. If you follow the manual, you’ll have to completely re-cut all parts and start all over on this step! Work from the wing, not the plans! Take all 6 ply pieces and the center wedge. Using a ruler, calculate how much to remove from the wedge to get it all to fit into the cavity of the wing. Once the excess has been removed, dry-fit one side and insert down into the cavity of the upper wing. Do likewise with the other 3 ply pieces. You will have to eyeball how far down into the cavity the plys should go. Then, you’ll have to cut and trim the plys to get a good fit. Remember, the top wing will friction-fit into this cavity with ¼-20 or smaller nylon bolts. Mark with pencil onto the wedge in order to know where to make your final glue joints. Don’t rush this step! Your wing incidence depends upon being accurate. The manual simply tells you to epoxy the plys together and then onto the wedge. The plys must be measured, trimmed and aligned prior to gluing to the balsa wedge. This was my biggest challenge in building the entire model. Once completed though, it makes a great and very secure wing attachment.

PointMagu

My Feedback: (11)

The Global Wacky Waco is not a beginner’s airplane. However, anyone with intermediate building experience should be able to tackle the few challenges that present themselves. I’ve tried to present the assembly process as clearly and as accurately as I could. My powerplant is an OS Max, .60FP swinging a 12x6 wooden prop. The FP is no longer manufactured but mine is brand new in the box and should prove to be more than adequate to pull this baby around the sky. Hopefully, I’ll someday have a .90 FS to try. Four stroke engines simply seem to lend themselves best to biplanes….

Once I get the whole thing finished and covered, I'll start the final segment on rigging and radio installation. Hope this helps anyone out there that comes across this bipe...either at the field, in someone's garage or on an auction site. It's a moderate amount of work, especially in today's age of Oriental ARF's. However, I'm of a mind that she's worth it.....

Don Carner
Cumberland, MD

tinkerbob

My Feedback: (13)

Have been flying a Wacky Waco for a while now. I had to rotate the landing gear a bit more forward to keep the plane from nosing over on our grass field. I did this by drilling a single bottom gear hole forward about 1/2 inch from the original. Also the motor I use, ASP .90, is quite a vibrator and I have to tighten things periodically. I was told a .60 would be marginal. Now, I don't think that is the case. The .90 performs very well. I can do knife edge loops and the snap rate is pretty violent. I recommend a small receiver. My Futaba 7 ch. bulges the wing mount area some.
Bob

brentp76

My Feedback: (14)

I had mine with a YS 110, Flew fantastic. I was just about able to do a sean tucker double hammerhead it was a fun plane to fly... Was that is until I put into a flat spin that it did not want to get out of, finally got it out of the spin to put it into a secondary spin... an well.... waco no more.. it was fun while it lasted.. about 15 flights.

PointMagu

My Feedback: (11)

With the flying season about shot, my ARF's and other projects are being placed on back-burners until I finalize the several "other" issues I've got in the works.

The Waco bipe was a Spring idea that got side-tracked once flying season rolled around. Too nice to build so I shelved this one along with a few others.

I tinkered with her off and on but now am faced with total completion prior to getting involved with my Curtis Robin from 1939 plans.

I've discovered pull-pull and other "new" ideas,(at least to me) and want to incorporate them in the Waco. Central Hobbies carbon tubes will be used on ailerons and elevator while the Sullivan Bros. pull-pull accessory will grace the rudder. I really like their chromed control horns and have stocked up on them. So-long nylon fittings!

I have to complete one remaining top aileron, install the top center trailing edge piece and I'm into final sanding. I'm going to heed the advice given regarding the potential nose-overs and cant the gear out a 1/2". I'm going to use a set of pants from an old Chipmunk kit and glass the crappy cowling Global provided. I've yet to decide on the engine mounting arrangement. I postulated on several different approaches to overcome the cheap poplar ply bearers included in the design.

Today, I spackled and placed the cap strips on the upper wing. If it rains tomorrow and the Ultra Stick is grounded yet another week, the Waco will get all-day attention...


More to follow...

PointMagu

PointMagu

My Feedback: (11)

Made a few modifications and continued sanding, overall.

I finally decided to keep the plane basically as designed. However, I just couldn't bring myself to use the crap poplar ply landing gear plates nor the same material for the engine bearers. So....I substituted 5-ply aircraft grade SIG plywood for both. I used 30 min. epoxy, clamped and slept on it.

The upper wing center cabane arrangement needed more attention so I epoxied 2 dowels, added another 1/8" ply plate for rear hold-down bolts and spackled all the gaps and cracks I had from my basic construction.

I completed the ailerons, rounded and slotted all the surfaces and added the ply plates to the inner, bottom wing panels.

Since my ASP .90 is on the rack due to a cracked head gasket, the Ultra Sport is grouded for abit. This will allow me to finish up a few minor details such as glassing the inside of the ABS plastic cowling that by itself, isn't worth using and getting the vertical stab installed on the fuselage.

I've got a roll of OD and Cub Yellow just waiting to be applied. I still need a set of Stars and Balls for my pre-WW-II motif.

Here's a few that I took after today's attentions:

PointMagu

My Feedback: (11)

Well, I've discovered an error in my building.

I use a hollow core door as a building surface and the weights that I use caused the thin veneer to bow during my upper wing construction. Now, I like to place some wash-out at the tips but the left panel is way off...about 3/4" off.

My club president suggested a few ideas but I hit upon this method just this evening.

I'm using the very weights that helped to create this situation in the 1st place. I have purchased a 48" building board from Tower Hobbies and will be building ALL future wings and fuselages on it!

Anyway, I'm clamping the trailing edge down and soaking the entire left panel with ammonia/water.

Study, (or glance, lol) the photos. If this works, I'll have stumbled upon a simple wing warping solution.

The dry assembled photo illustrates the warp before "therapy":

PointMagu

My Feedback: (11)

Today is gorgeous but no flying. I managed to replace the ASP on my US 60,(traded an AT6 for a new engine) and flew all day Saturday. I spent last evening covering the top wing and ailerons of the Waco. This SIG covering is awesome!

I've been putting off installing the vertical fin as the width of the wood is too wide to fit into the slot created when laminating the fuselage.(see my previous post). I used a metal straight edge and sanded along it to get a narrower cross section. After a few minutes, I knocked enough material off to get a nice fit. I cut a few miscellaneous pieces of balsa to finish up the tail section and applied with CA.

Next, I mixed up a batch of 12 min epoxy and cut strips of 6oz. glass cloth to start on the cowling. I cut the ABS halves out and glued them together with gap-filling CA. I applied a 4" wide piece of cloth, top and bottom along the inside seams. Once this sets, I will finish up by applying 2 larger pieces inside to make the whole affair more rigid for flight ops. I thinned the 12 min with 91% isopropyl alcohol. Working with glass cloth and epoxy has to be the stickiest and most worrisome aspect in this hobby! I'd rather cut hinge lines! Anyway, with what seemed like a pint of alcohol later, I had everythig cleaned up and put away.

I really need a nice set of pre-WWII stars with meatballs to adorn this bird. Major Decal seems to be the only supplier out there. I'd like to find an alternative source if for no other reason than to simply have something "different" than everyone else. Their "grim reaper" decal is seen on everything and the eagle is great but a WWI insignia.

Here's what I've been going on about:

PointMagu

My Feedback: (11)

Things have been progressing nicely with the bipe.

I've managed to cover both wings in Cub yellow ala SIG Aerokote. This covering is fantastic. Talk about shrink and versatility! It covers itself without bubbling. A heat gun removes all "boo-boo's" and wrinkles. I love it. Anyway, the tail group is done and the fuselage got a covering of OD of the same material.

Since this is a profile, I opted not to cover the entire fuselage so I stopped just forward of the cowling bulkheads. From this point to the nose I sealed the wood with 30 min epoxy thinned with 91% isopropyl alcohol. I flowed the mixture onto the bare wood and all around the ply engine bearers. I plan on shooting several coats of white Formula U to this area to make cleanup after flying a snap.

The cowling turned out really nice considering the amount of effort I exerted. I was initially concerned that the flimsy ABS would prove useless but the 6oz. fiberglassing, rough sanding and a bit of final wet sanding really produced a decent cowl. Don't misunderstand me here...it certainly isn't show quality but it will pass for Sunday flying.

I covered the ply outer cabanes in silver but they just don't look very good. I bought several K&S Engineering aluminum airfoil tubes. I'm going to modify them by carving up the stock ply cabanes, slim them down slightly and insert them up into the aluminum. In this manner, I won't have to make fancy cuts and angles to the tubes to form the "N's". By the time the ply plates are secured into the wing hard points, the whole affair will finish up well. I cut and trimmed the canopy. I'll be applying thin striping to the insides to replicate metal framing.

I've yet to decide if cutting servo holes in the tail bears merit. I'm not thrilled about running pushrods back along the fuselage but I also worry about the weight of having 2 servos sitting back there. Since space is at a premium in the lower wings and situating the receiver and battery pack will be a neat trick, I may very well opt to free up the space those 2 servos would otherwise occupy and move everthing aft. My only challenge then would be the servo leads running back to the wing root. I'll slice outer nyrod tubing lengthwise and slip the wire leads inside leaving a cutout of sorts for the connectors. This will in turn be attached to the fuselage side with nylon hold downs screwed into the wood. The SIG covering will easily adhere to the nyrod and make a nice finished appearance. Aileron pushrods as well as the rudder and elevator will feature Central Hobbies carbon fiber tubes with titanium ends. These are the best for lightness and strength in my opinion.

The landing gear is functional but not altogether attractive. I plan on rounding the tops of the aluminum straps and then airfoiling the down legs by adding balsa and then applying 30 min epoxy followed by light sanding and several shots of gloss black. Williams Bros. scale 3-1/2" wheels will round it all out. Fortunately, I have several pairs of the Williams Bros. accessories on hand as well as some of their machine gun kits so accesorizing will be easy.

I'm on my way to Hagerstown this morning so no time for photos now. I'll take a few and post back here tonight after I'm home.

I think overall, this is going to turn out to be an attractive flyer. We'll see...

PointMagu
Cumberland, MD.


"There I was...flat on my back..."

PointMagu

My Feedback: (11)

Ok, here's some photos. My ability to hold parts and shoot pictures leaves much to be desired as these show, lol...

PointMagu

My Feedback: (11)

Well, I realize not many folks are interested in a defunct Global kit project but there are a few out there on eBay,(where I found mine) so I'm gonna continue with this thread until the thing's done, lol...

Here's a few from tonight. I'm working on the outboard cabanes now, fleshing them out with balsa. Instead of inserting them into the aluminum like I proposed before... The landing gear turned out so nice I'm inspired to follow suit with these.

mrbigg

My Feedback: (21)

I'm watching. Looking sharp. Keep the thread going!

philfun

My Feedback: (58)

Dito for me.Very interesting.

Thanks a lot

Phil

PointMagu

My Feedback: (11)

Well, thanks guys! I wuz beginnin' to think I 've been talking to myself, lol...

Last night didn't see much accomplished. I managed to finish rounding out the outer cabanes and filled the few imperfections with spackling. I'll cover them tonight with silver UltraKote. The inner cabanes are stamped aluminum and too intricate to do what I've done with the outers. They will remain, "as-is".

The Formula U that I sprayed the forward fuselage with is STILL tacky after 2-1/2 days. I beginning to worry that it will never fully cure and setup. The can is years old but never used until this project. I'm going to shoot the cowling with enamels and toss the remainder of the
Pactra.

I'll be posting more tonight.

Again, thanks for the kind words!

PointMagu

"There I was, flat on my back..."

PointMagu

My Feedback: (11)

Well, it calls for 5mph winds, sunny and a high in the low 50's tomorrow. So...............

It's preparing for a day's flying this evening with little done on the Waco I did manage to get the lower wing panels epoxied onto the fuselage. I forgot about trimming the covering and almost had a small disaster on my hands...just goes to prove that rushing into anything has consequences!

The bulkheads that secure the cowling,(only on the port side however?) will be duplicated and installed on the starboard side as well.
In this manner, the cowling will have added strength in flight. Hopefully, tomorrow evening and Sunday will have more to share.

Cont:

PointMagu

My Feedback: (11)

Well it's been a few days since I last posted...due primarily to the Holiday.

I've managed to get a few odds and ends done and the bipe is really starting to look like it will fly!

I added the tailwheel, situated the servos for elevator and rudder in the tail section and ran the wiring.

When I put a 12x5 prop on my OS 60FP, there doesn't look to be enough blade to clear the cowl...it'll be interesting to see how well this engine hauls the airplane.

Here's few more photos showing where I'm at to date:

mrbigg

My Feedback: (21)

looking sharp! I wish I was that far with mine...........

PointMagu

My Feedback: (11)

LOL...


Well, this project has lasted all year! I'd start this and get side-tracked onto something else...just like now! My buddy has a H-9 P-51 and it flew for the 1st time earlier this month and got me all inspired to finish mine. Yep, the Waco has been "shelved a week or so".

Here's what I'm about right now...

I will be finishing the Waco before Christmas so stayed tuned!

MrBigg, any photos of your bird??? I'd love to see 'em!

PointMagu



"There I was, flat on my back..."