RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Full Build BUILDER'S Thread  
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RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 2/29/2008 4:35:16 PM   
YellowAircraft



Posts: 3086
Joined: 1/5/2002
From: San Diego, CA, USA
Status: offline 		Sean,

Thanks, buddy.

Invertmast,

CST is having a sale on carbon plate 1/8"x3"x12" across. That's what I used. You only need to get it across that narrow spot a ways like in my pic. Remember that the front bulkhead you're gonna get will already have s layer of 6-oz carbon cloth between the main ply and the doubler ply. Even if you use your 1/16" diamond plate, I think you'll be alright. I felt better about the 1/8" carbon, though...

Jeff,

Interestingly, that's the method we use on the F-15. I'm guessing the fact that the fins on that one are 90 degrees straight up makes it easier to get the geometry right with the little stab/fin control-yoke-box-dealeo. Looking at the pics in the one you show, I see the idea, but i'd be concerned about a positive, slop/bind-free rudder. I'm sure his is fine, but I'd probably end up with some kind of a problem.

The only thing I don't like about removing the rudder is the way the wire is stowed. That looks like it's gonna be a PITA. The removal of the rudder itself is easy (and kinda cool if you ask me) if it's anything like the flaperons on the F-16. I don't intend to do the wood plug in the top of the fin deal. I'll just have the tip of that wire bent back and sitting up there as inconspicuously as possible. I'll just tell myself that it's some kind of antenna or sensor that the real one has...

What I aint gonna do is put the servo in the fin. I've never understood why people do that and ruin one of the nicer features of this bird--no exposed linkages! Some say you get more positive control or whatever, but all I see is an ugly fin and rudder linkage hanging out and more lead in the nose. With the proper hardware, there doesn't need to be any more slop or flex with the servos up near the rear of the hatch. You get shorter servo leads, too.

Does anyone know if there's a good bandsaw blade for carbon plate? I've gone through two of the stock metal-cutting blades you get at home depot, and they would barely cut balsa at this point. How are those of you without exotic equipment at your disposal cutting your carbon?

_____________________________

Yellow Aircraft, JetCat Engines, Skymaster ARF+ and Turn Key Jets
www.cyctheatre.com

(in reply to invertmast)
       Post #: 26

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 2/29/2008 5:53:00 PM   
invertmast


 

Posts: 710
Joined: 12/11/2003
From: Bridgewater, VA, USA
Status: offline 		well if ya think the 1/16" stuff i have "should" be enough, i have some 3/32" also that would fit from end to end. I could hysol a layer of 1/16 and 3/32, to make it 5/32" and bolt it w/ some 4-40 or 6-32 screws across the narrow portion, then encapsulate the reciever in 1/4" 10 ply. now if my parts would get here from charles...

_____________________________

Thomas W.
Avant FX, Trex 600N, YA F-18 Twin, Ziroli Panther..

(in reply to YellowAircraft)
       Post #: 27

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 2/29/2008 6:44:04 PM   
jkirkon



Posts: 367
Joined: 1/4/2003
From: Stratford, NJ, USA
Status: offline 		Shaun,

I do agree with your concerns about slop in the rudder linkage....... I think I would put another 90* bend in the linkage that would slip up into a brass tube inside the rudder. The brass tube would run about 1" vertically in the base of the rudder.
That would (should) eliminate any slop in that setup.

The stock setup IS just like the F-16 flaperon. They both work very well, I was just looking to make it a wee bit simpler to remove the fins.
I'm not HUGELY concerned about it, as I doubt that I will be removing the fins that often anyways.

Nice job on your build. In particular, I like the way you encapsulated the spar recievers. I am going to go back and retrofit mine in a similar manner.

Cheers!

Jeff

(in reply to invertmast)
       Post #: 28

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 2/29/2008 11:03:54 PM   
yeahbaby



Posts: 2465
Joined: 12/7/2001
From: FT Worth, TX, USA
Status: offline 		dude

nice work on the spar assembly carbon laminate!! Gary Baker did a similar ply capture plate on the wing spar channels also. is there a new method to tieing the spars into the channels? doesn't look like there is enough room to accomodate the bolt heads in the standard configuration.

the thing is gonna be rocket ship with twin 120s/titans.

keep 'em coming



< Message edited by yeahbaby -- 2/29/2008 11:13:31 PM >

(in reply to YellowAircraft)
       Post #: 29

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/1/2008 12:30:13 AM   
invertmast


 

Posts: 710
Joined: 12/11/2003
From: Bridgewater, VA, USA
Status: offline 		Here's what i've got on my project so far. I added a removable nose cone to facilitate access to the batteries, but i didn't want exposed bolts, so i made 2 bulkheads to put 3 6-32 bolts to hold on the nose thru the interior of the plane. Also got the new forward bulkhead mocked into place and trimmed to fit the twin inlet ducts, found some 1/8" carbon locally, so the forward former is in the process of drying w/ that on the backside, then finish copying Shaun's setup, then wait for my order from todd (dreamworksrc) to show up w/ my hysol and air system parts.... Now i just have to figure out some way of stripping the paint off the fuselage w/o spending days of sanding by hand. any idea's?

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Thomas W.
Avant FX, Trex 600N, YA F-18 Twin, Ziroli Panther..

(in reply to yeahbaby)
       Post #: 30

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/1/2008 2:47:00 AM   
YellowAircraft



Posts: 3086
Joined: 1/5/2002
From: San Diego, CA, USA
Status: offline 		Buck,

No, you're right--there's supposed to be some bolts going up into there. They will. The bottom part of the ply incapsulation will have some of the material removed when room is made for the bolt heads, but those little pieces of wood left will be aeropoxied on and glassed to the fuse. They'll make a difference when it comes to helping to keep the receiver from shifting. Seems like a whole lotta disasters would have to happen before that thing let go.

_____________________________

Yellow Aircraft, JetCat Engines, Skymaster ARF+ and Turn Key Jets
www.cyctheatre.com

(in reply to invertmast)
       Post #: 31

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/1/2008 3:37:10 AM   
yeahbaby



Posts: 2465
Joined: 12/7/2001
From: FT Worth, TX, USA
Status: offline 		right on amigo. I definitely think capturing the wing spar channels is a great idea and worth incorporating.

keep 'em coming


(in reply to YellowAircraft)
       Post #: 32

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/3/2008 12:27:55 AM   
invertmast


 

Posts: 710
Joined: 12/11/2003
From: Bridgewater, VA, USA
Status: offline 		Here's what i've got done on my forward former so far. Its surrounded w/ 2 layers of 1/8" Carbon fiber. I captured the top part of the reciever w/ 2 legs of the CF piece on the rear of the former, I plan on capturing the rest of it w/ 1/4" 10 ply birch and routing out to go over the carbon fiber "fingers" this way the carbon fiber acts sort of like a lock for the plywood so it wont rotate any. I also put 4 4-40 bolts and blind nuts thru all the layers to hold it all together. The setup so far is much stronger feeling than the original and doesn't flex as much. It also only add'd about 3-6 oz to the overall weight i believe of the bulkhead (i haven't weighed it yet)

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Thomas W.
Avant FX, Trex 600N, YA F-18 Twin, Ziroli Panther..

(in reply to yeahbaby)
       Post #: 33

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/3/2008 4:56:51 AM   
YellowAircraft



Posts: 3086
Joined: 1/5/2002
From: San Diego, CA, USA
Status: offline 		Hey,

Looks good, dude!

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www.cyctheatre.com

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       Post #: 34

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/4/2008 3:21:55 AM   
invertmast


 

Posts: 710
Joined: 12/11/2003
From: Bridgewater, VA, USA
Status: offline 		here's my completed forward bulkhead. The thing is pretty dang strong compared to before all the mods.. and for those of you wondering, the orange stuff on the bolts is torque-seal, that way i can tell if the bolts ever loosen up and rotate. Oh btw, i've been using a reinforced fiber cutting disc. "roto-zip" rotary cutter in a dremel tool and a zona saw to cut all these parts by hand. not the most efficient way of doing things, but all my power tools are 4 states away. lol

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< Message edited by invertmast -- 3/4/2008 3:34:21 AM >

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Thomas W.
Avant FX, Trex 600N, YA F-18 Twin, Ziroli Panther..

(in reply to YellowAircraft)
       Post #: 35

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/5/2008 2:08:37 AM   
invertmast


 

Posts: 710
Joined: 12/11/2003
From: Bridgewater, VA, USA
Status: offline 		alright.. here's probly a dumb question. in the old manual, they say to mix 30 min. epoxy and "milled fibers" to hold the aluminum spars in the wing panels. what is "milled fibers"? First guess i would assume its the same thing as micro ballons? If not, can someone point me in the right direction in what to use.

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Thomas W.
Avant FX, Trex 600N, YA F-18 Twin, Ziroli Panther..

(in reply to invertmast)
       Post #: 36

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/5/2008 4:10:11 AM   
pappy35


 

Posts: 356
Joined: 10/30/2006
From: Liberty Township, OH, USA
Status: offline 		Not quite the same thing.

Microballons are designed to add fluff (air-filled microscopic spheres) to decrease the density of the resin and yield an easy(er) to sand material but is quite brittle. Milled fibers are more like ground-up fiberglass cloth which yields much better tensile properties while still being lighter and easier to sand than pure resin.


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Al

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       Post #: 37

RE: Yellow Aircraft F/A-18C Twin (Two Engines) KIT Fu... - 3/5/2008 6:02:37 AM   
YellowAircraft



Posts: 3086
Joined: 1/5/2002
From: San Diego, CA, USA
Status: offline 		Hi,

Great answer, Pappy. You want to use the milled fibers in the wing spar case. I'd suggest 60-minute epoxy, so you can heat it up a bit to get it to flow more viscously. It's very important that you make sure there aren't large air bubbles trapped in that slot. It's also important that you get some of that epoxy/fibres mix into the lightening holes in the spar. Do it right, and you'll have NO problems with that spar system.

Wait, didn't your plane come with the wings already done??

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Yellow Aircraft, JetCat Engines, Skymaster ARF+ and Turn Key Jets
www.cyctheatre.com

(in reply to pappy35)