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General control line discussion => Open Forum => Topic started by: wwwarbird on December 29, 2007, 06:24:15 AM
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Here is a small preview of my current project, a built-up profile PBY Catalina. It is an original design by myself, has a 64" wingspan with 700 square inches, a 30" stab/elevator span, 17" flap to elevator moment, and will use two Saito .30's. I will be posting more photos and info soon, if I can figure out how. ;D
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Bird,
Very SWEET!!!!!
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The picture won't get bigger for me. Bummer. That looks interesting.
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Wayne,
You have gone "Twin Happy!!!!" Should we blame Whitely?
That PBY is beautiful. It has always been on of my favorites.
I love when someone pushes the envelope. My hat is off to you.
I think that we have finally come to an age where some of us are no longer afraid to try something different. Of, course Jack Sheeks was way ahead of us in that department.
Looks like you will have to play with the verticle CG. Where will your leadouts be?
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Tom,
Thanks!
I had debated this project for the last couple of years, and a while ago just decided to go for it. The bellcrank is mounted externally on the fuse, and I designed a two-way adjustable leadout guide out at the tip. I'm thinking that the leadouts will end up between 1 and 2 inches below the wing once I get it dialed in.
As soon as I can figure out how to get these darn pics on here, there will be photos of all the details, hopefully tonite after work.
Stay tuned... ;D
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Warbird, that is an absolutely AWESOME #^ #^ #^ H^^ H^^ project!!!!!!!!!!!! I hope you have the utmost success with it!
If it pans out to be prety good will you then do a full fuse' ship? Awe, come on, go for it!
The PBY is one of my favorites, too. But I always wanted to build it for scale. (No guts.) ~> ~^
Blessings,
Will
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That is one nice plane!!! John
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Wayne,
That is looking pretty sweet. You are quite the balsa whittler. I am looking forward to seeing a little more of it in the future. BTW, there should be a two thumbs up icon for your airplane and well organized shop.
John
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For now, the only way I can make it work to add photos is to add more reply posts, sorry Sparky.
Here is a shot as she sits today...
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A 3/4 rear view...
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Top view...
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A shot showing the bellcrank mount. The aluminum L/G retainers you see are only temporary. Yet to come are wing struts that will also double as L/G retainers...
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A two-way adjustable leadout guide that will stick down below the wingtip...
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A side shot. The flap is yet to be cut off a bit on each end to add trim tabs...
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The fuselage forks up into the wing between two closely spaced 1/8" thick center ribs. Top and bottom spars are continuous...
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Tail feathers, all built-up construction...
(That's a modified Tom Niebuhr Consolidated "Wow" with a .25 LA-S in the background, a future story ;D)
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Before Polyspan...
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Outboard side...
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Wow.
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Absolute genius!
Frederick
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How will something like this do inverted? I like twins, but a high wing stunter?
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The fuselage forks up into the wing between two closely space 1/8" thick center ribs. Top and bottom spars are continuous...
Hey Warbird, is there any reinforcment in the wing pylon area? Looks like a "break me here" spot if just the horizontal grain.
Sorry, don't mean to be critical. I really like the bird and would hate to see it come to an ealy end. I'm anxious to see it finished.
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If the leadouts are aligned to the vertical CG, it will fly wings level both upright and inverted. Otherwise, not. But I am also concerned with the "pylon" mounted wing being a problem. If the pylon sheers above the bellcrank mount, the wing and engines might get loose from the lines. The pushrod arrangements will also be interesting. Good or bad is possible. Good is best, IMO, but always more work.
The one thing I'd regret, is not being able to fly this from water. Alas, only so much you can do with a profile bird. H^^ Steve
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Wayne,
Your workmanship is awesome. I also admire your solutions to some of the inherant problems. The challenges are certainly worth it.
This not the first high wing stunter, but I have never seen a twin high winger. It should fly well.
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Beautiful model! Nice to see something different and out of the box of thinking. I like the various adjustments to the leadouts, great. Thats one big flap. Would be interesting to see how the plane will fly with a flap that span :). Please continue to post pictures. Will be looking forward to it. Thanks H^^
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I have a similar, more or less, leadout guide situation. I'm building a Wombat, a biplane, for OTS. There are no interplane struts and the leadout guide is on the lower wing. I made the wingtip like usual with rails for the slider in the tip rib, but there is also a 1/8 in vertical slot between the tip rib and the tip. The slider has three bolts, one to hold it in place, and two to hold the leadout guide stuck down into the slot. I picture a simple hole at the top of the leadout guide with both leadouts going through and will have the leadout guide moveable up and down. The leadout guide is going to be made after I hang the airplane and figure out where it needs to be in relation to the vertical CG.
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What a fabulous project! H^^ CLP** BW@ Everything looks good (even the workshop!) but I think my favorite piece of detailing (so far) is the way you laminated the gun blisters on the rear fuselage! 8)
Normally hi-wings get into trouble with vertical CG position, but on your bird the heaviest components (the two Saitos) are in line with the wing. You still have a fairly tall fuselage and landing gear to worry about, but I'll bet your leadout guide system will win the day for you. You MIGHT want to leave yourself some room to move the BELLCRANK up or down on its pivot bolt between the upper and lower mounts. I think you will still want the BC to be level with your leadouts when it is all trimmed out...
You have GOT to keep us posted on this one! y1
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Very cool Wayne!
Keep the photos coming.
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Warbird,
That is some of the most impeccable workmanship I have seen for a very loooooooong time!!! Absolutely wonderful. How would you like to come build my guitars for me - I could totally retire!
Blessings,
Will
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very nice and a one of a kind. love it
Randy may have a point on the pylon, but a couple of dowels drilled in vertically and the worry is gone.
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About the PBY pylon construction;
The perimiter of the PBY's fuselage is completely built-up with 1/2" x 1/2" balsa, and then sheeted with 1/8", yielding 3/4" total thickness. All but the pylon area is internally "trussed" with 1/2" x 1/4". Inside the fuse, at the pylon, there is a solid, quite hard, 6" wide x 1/2" thick piece with the grain running vertically from the very top of the pylon, all the way down to, and meeting with, the horizontally mounted landing gear blocks. The top and bottom bellcrank mounts are made of 1/8" H.D. plywood, and they fit all the way through the fuse to the inside of the 1/8" sheet on the outboard side, and are epoxied in. Then, drilled from the very top of the pylon, there are two 1/4" hard dowels epoxied in 1/2" apart from each other that also pass all the way through the bellcrank mount to about 1" below it. I'm pretty confident that it would take a hit from a dump truck to break this assembly apart. ;D
Thanks for the concern. y1
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Amen to that! Thanks for calming our fears...completely, I might add. You do nice work. I would be interested in plans for this model, and suspect a lot of others would, also. H^^ Steve
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Thanks Steve.
I should also mention that while constructing the fuse as mentioned above, I sanded the rearward taper into it before sheeting it. Then, the 1/8" trussed fin assembly was attached. The entire fuse/fin was then sheeted as a unit, greatly helping the torsional rigidity to support the 30" stabilizer, allowing IT to "stabilize". ;D
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I'm a sucker for multi-engine models and yours is awesome! Hope it flies as good as it looks. Just an observation that might help for later on. It appears that you have quite a lot of flap area and a fairly short coupled hinge moment. You might think about using a 2 to one elevator flap ratio. I found out the hard way on one of mine as the elevator wouldn't/couldn't overcome the pitching moment of the flaps. Had to increase the elevator size and slow the flaps down to get it all to work. If you make it all adjustable should be no problem. Hope to see pics when it is done. Nice job! RJ
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Thanks alot Bob, that's really good info, and something I'll definitely keep in mind.
The plus in this case for what you are describing is that the elevators on this model are quite large already. I will also be cutting the flap off on each end yet to become inboard and outboard trim tabs. After that, the relationship of flap to elevator area ends up being right in the ballpark of a typical PA Stunter. Also, the entire control system will be external, so it won't be too tough to change things if necessary.
(I spent a lot of time making my brain hurt before I started construction of this model.) :## ;D
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Back from travels- Very nice job. The Cat is a real pretty bird! I have thought about the PBY myself as it is sorta "in line". The model may show a tendancy to fly with the wing up upright and down inverted as the fuselage is going to create some "lift" (horizontally) due to the fact that we fly in a circle. I think you have covered all the bases and should have a fine flying airplane when finished. Will look for photos and a flight report! How much wing area and what power?
Don
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Warbird: Great looking PBY! You'll love the sound of two 4S motors inflight.
I have two Saito 40s on my XF-11 and they sound great when they are
synced-up. I like the way you've done your leadout guide. I discovered on
my Sig Ultimate Bipe that it is very important to get the leadouts on the
vertical cg when they are not coming directly out of the wing. If they aren't
the plane will fly "tilted".
Great Job, Steve
PS: A couple of XF-11 pics.
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Warbird
Here is a pictue of our local PBY.
Willis
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Here's ours.
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I liked seeing the PBY photos. My dad was stationed in Hawaii with PBYs during WWII. Looking forward to see the photo of the finished model.
Dave
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I am so loving this. My Uncle flew PBYs in WW2. My dad and I watched the Borate bombers work the fires in central Washington over the years. Nothing like wathcing one of these beasts touch down on the water to siphon up a load to drop on the fire. In fact, Dad was looking at some pictures and the plans for my 109 over christmas this year and he was asking if I was ever going to do a PBY. Not now,, you took that right away, and more power to ya,, looks great, I think one time they did have a built pond for the regionals, now that could be fun, a stunt pattern over the water, in fact, that may be a way to make my planes last longer,, lol,
OK probably not
great looking project, keep us posted.
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This is definitely a very good project. Sounds like everything has been well thought out. It could easily lead to a full blown all out stunt plane on the order of Windy's twins!
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We had one cruise past last (suday ) evening.
Now thats a GREAT model . But ,would the props clear the deck without the U/C.
Its a plane id studdied too. Tailplane in line with wing . Id thought it migt need to go clockwise for full F2B pattern, so left hand props and injuns if all the nasties cumulated anticlockwise .
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Here's a picture of the pylon discussed in detail earlier...
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Man this is great!!!PBY --- another admirer. Pictures and work is wonderful. Keep it comeing.
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On Holiday , or has there been more pressing commitments ? or shouldnt we ask !
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On Holiday , or has there been more pressing commitments ? or shouldnt we ask !
I agree.. any more progress?
Big Bear
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This is a fantastic project, I hope it flies as well as it looks...............I am following your progress with a lot of interest.
Dalton H.
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It's done. It's flown. Wayne brought it to our June meeting and it's even MORE impressive in its final pre-WWII livery. I think Wayne said Keith Sandberg had the inaugural flight. Simply a fantastic piece of ingenuity and craftsmanship. Our club (MPLS Piston Poppers) is small but there's a lot of talent in our li'l bitty group.
We've been promised photos and I can post 'em as soon as someone sends them to me.
http://www.facebook.com/album.php?aid=31893&id=1455821605&l=cc13baa276
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I'll take that as a hint Steve. I've got a whole bunch of pics in my camera now, we'll have to get together soon. I'm definitely much more of a model builder than a computer dude... ;D