Shaun Evans

Hey,

Makin' some progress. I'm building two of these at the same time, so it's a slow-go at times. I round-robin between the two (glue's drying on one--I'm sanding on the other).

I've got the anhedral set on mine. Mine's the second-to-latest generation kit, and I'm gonna retro the removeable fin kit into it.

On the bulkhead, I've got 1/8" carbon plate bolted/aeropoxied to both sides of it. I've got 1/4" 5-ply doublers that surround the spar receiver, locking them in place. Between the glue, the bolts and the doubler, I'm in pretty good shape.

seanreit

My Feedback: (60)

Looks good dude!

jkirkon

My Feedback: (6)

I like the removable fin option, however, if I had to do it all over again, I would not do it per the instructions.
I would set up the rudder torque rod so that you do not have to remove the rudder, before removing the fin. The torque rod would be sort of 'Z' shaped, with the rod fitting into a slot on the base of the rudder. This way, you could remove the fin/rudder as a unit, with simply 2 screws.
Joe Ferrante sent me some pics of his Hornet with the fins done this way. Seems much simpler than Yellow's method.
If I can find them, I'll post them.

I believe the Ultra Bandit works this way as well.

Jeff

jkirkon

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Here's Joe ferrente's method:

invertmast

My Feedback: (23)

Shaun,
thanks for the pics. your explanation makes much more sense now, guess i need to put in an order for some 1/8" carbon

Shaun Evans

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?

invertmast

My Feedback: (23)

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...

jkirkon

My Feedback: (6)

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

jkirkon

My Feedback: (6)

BTW: a great source for everything you always wanted to know about bandsaw blades, and supplier of all types of blades:
www.bandsawblade.com


Jeff

yeahbaby

My Feedback: (21)

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

invertmast

My Feedback: (23)

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?

Shaun Evans

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.

yeahbaby

My Feedback: (21)

right on amigo. I definitely think capturing the wing spar channels is a great idea and worth incorporating.

keep 'em coming

invertmast

My Feedback: (23)

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)

Shaun Evans

Hey,

Looks good, dude!

invertmast

My Feedback: (23)

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

invertmast

My Feedback: (23)

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.

pappy35

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.

Shaun Evans

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??

invertmast

My Feedback: (23)

nope, those wings were damaged in a landing accident by a previous owner, so i've got a new set to build that has the carbon reinforcement between the foam and balsa skin. Ok, i've got a good bit of 5oz and 2oz glass cloth floating around. can i cut small strips (1/2" to 1" wide) of the 5oz cloth and seperate the glass strands from each other to get a "milled fibers" type material? Reason i ask, is the places i've found that sell the stuff only sell it in 3lb tubs (or similar sizes) for $80 and i hate buying that much when i'll probly use 1/10 of a pound.

pappy35

Five bucks at Horizon or your local hobby shop.

[link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=BVM1905]BVM Milled Fiberglass @ Horizon[/link]

invertmast

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now that i can handle! thanks a bunch.

invertmast

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I was sitting here tonight laying out the cut lines for the flaps and ailerons, and noticed the wing trailing edge cap is pretty close to the aft aluminum wing spar. And it seems thru some research, most are using 3/16" or 1/8" robart hinge points to hinge the flaps and ailerons. but in doing so, you have to drill thru the aft aluminum spar, which i'm not very fond of. So what is everyone using for flap hinges? I found these: http://www.dreamworksrc.com/catalog/...roducts_id=552 and they look promising, just not sure if they will handle the load or not. and here's a few pics of progress so far..

David Jackson

My Feedback: (15)

Hey Guys,

A couple of years ago, I carried my twin F-18 to the local field just to run the engines and to taxi the plane around to make sure it tracked straight. What I discovered was the location of the air cylinders for the main retract doors were too close to the engines. After running the plane for 5 minutes, all the airlines to main door cylinders were damaged. I plan to build a box around the door cylinders and line it with BVM ceramic blanket to protect the airline from the heat of the engines. If any of you have a better solution to this problem, please post it.

myersflyers

My Feedback: (33)

Try some of the orange strip from Home Depot. It's about 9.00 a quart, but well worth the money. I use it to strip everything from varnish to epoxy. No harmful odors, stays where you put it (thixotropic), starts working in 30 minutes and the paint practically peels off. Does'nt hurt fiberglass at all.

BTW, I use a scroll saw on slow speed with a metal cutting blade to cut carbon. It does a fairly good job.