I don't know about other brands, but Futaba retract servos aren't very powerful. (136G - 70oz) Unless you go with a Quarter scale retract servo and there isn't enough room in the thin F-18 wing. You could use a programmable digital like Hitec so you could set the speed. I think you're going to need a lot of torque on the LE flaps. I saw a real nice F104 crash at the SW Fan Fly several years back, because one of the LE flaps did not retract.

That was going to be my next question.... where are you going to put the extra servos? That wing is mighty thin to start with.

Instead of locking pins, how about setting up the servo to move the linkage "over center" so that airloads can't force the flap back. Also, wouldn't the airloads on the flap in the "down" position actually help it retract? Can't help thinking about the non-powered L.E. of an A-4 which simply dropped at rest.... what held that up?

Just food for thought....

Bob

There is a low pressure area located on an airfoil at moderate angles of attack, on the forward top surface. This distribution would tend to lift the leading edge up.

Hitec I believe have a 90 oz-in retract servo available, but you are right that space might be a problem. I'd stay away from a torque rod arrangement, if I were doing it, but that would allow you to keep the servos inside the fuselage or LEX). Perhaps a couple of air cylinders along the span is the way to go, as previously suggested. I'm assuming this is the big F-18 kit?

Gordon,

I'm not a JR guy, but I'm going to use a channel expander on my Panther project and I've read the manual that JR has on line and here's my understanding of how it works.

The channel expander connects to one channel of your receiver as its input. You setup up to four "kick points," one for each expander output channel, which determine at what point each of the output channels is triggered. When the input channel is moved through its range, when it crosses the "kick point," that output channel is commanded to move from one end point to another - the direction of which is determined by which direction the input channel crossed the kick point. Its important to note the the output channels of the expander are non-proportional, and thus are only suitable for on/off type functions.

On my Panther, I am going to operate the split body flaps and speed brakes off of an expander that is driven by the same channel as the wing flaps. I'll set the channel expander up so that the first kick point for the split flaps is at the 50% point of the flap travel, and the speed brake kick point is at the 95% point of the flap channel. That way, the first 50% of the flap knob will only move the flaps down (i.e., for takeoff), at 50%, the split flaps will deploy all the way, and at 100%, all of the flaps will be at maximum extension and the speed brakes will deploy.

Bob

I figure a strong sail winch type in the wing root, actually the fuselage driving an axle that goes through the root end of the le flap, when u plug the wings to the fuse on setup, u plug in the le flap square end into the square hole in the fuse elage, much like the Byron ailerons on say the A4 skyhawk (if you've ever seen that)

so with the chanel expander I make the first kick point at 1% so that it pulls the safety pin out of the way so the le flap can travel, then the second kick point is at 100% travel so the pin is shoved back in the hole to lock the le in the retracted position..sound right

Going with expensive jets, the price of a top notch radio should not be a problem. Here is a quick explanation of the Multiplex top of the line radio the 4000:

With all the features a champion wants and needs! The Multiplex Profi mc 4000 is truely the pinnacle of modern transmitter technology.

More channels
All 12 channels are of equal value, equal speed and equal resolution. Any channel can be assigned to any control, or to any mixer output. There are no restrictions on any functions and all the mixer and adjustment facilities which the PROFI mc 4000 has to offer can be exploited to their full extent using all channels channels. The transmitter can be switched between 9 and 12 channels to suit the receiver, which means that you can use all MPX receivers - old and new - with this transmitter.
You can also use any other PPM FM receiver, regardless of make.



More timer functions
4 count-down/count-up timers with 1 sec. resolution, 1 count-down/count-up timer with 1/100 sec. resolution, 1 Lap timer with 99 memories for lap times, and with the optional Co-Pilot module you can actually hear your times spoken! It's an ideal training partner for contest work!


More mixer and adjustment facilities
e.g. 2-8 mixer inputs;

apply an effect curve (3 - 13 points) to any input
apply “slow” to any input
any input can be switched ON/OFF permanently, or left switchable
mixed functions can be defined as the input signal for a subsequent mixer function.
Even for complex models the set-up procedure is greatly simplified by the provision of “base types” (permanently stored sample applications) of typical model configurations, freely programmable mixers and a range of ready-made mixers for fixed-wing models and helicopters.

Servo monitor
An important aid to endpoint and mixing adjustments is the SERVO monitor, which displays the current servo travels for all functions simultaneously. This makes it much easier to locate the programming error when something does not work quite as you expected.


More model memories
25 - 100 models, depending on complexity, each with up to 5 flight modes and variable transition periods (0.1 - 10 sec.).


Customized to fit YOUR exact needs
Are you are looking for a tailor-made transmitter? One which meets your own personal requirements? No problem with Multiplex. Because we manufacture the equipment ourselves, we can assemble a system to fulfil your individual demands - right at the production stage!
The Profi mc 4000 Basic transmitter represents the basis for your transmitter, which is then fitted out to your personal specification. The following options are available: Scanner, Co-pilot, Upgraded Battery, Digi-adjusters, switches and stick-top switches.

Dude I've seen more crashes due to wrong mixing selected lately. 9c or JR will do all that you want.... but its not necessary for Y/a F-18.

I've seen it fly with ailerons and with elevons for control and both are great. Flaps or not it land great.

Real airplane uses computer since 4th Gen combat aircraft are designed with negative stability; for increased turn rate etc. You don't need the drooped LE on your f-18. Besides real hornet after cat shot fly's itself in correct burner setting by computer for first 1. 5 secs or so. Do you desire your R/c version/radio to do the same? Just checking.

As to wash-out. Wash-out is good and agree with 30 flaps and 15 for ailerons for full flapped wing settings. That way wingtip has more wash-out than root, since defined as measured at "Chord line" compared to relative wind. Inboard flaps has higher lift but also higher drag to slow down acft (good thing) yet still some drag and good lift on tips at 15 degrees. This ensures the inboard section will stall first allowing wingtips to carry you and prevent death roll (tip stall), especially if ailerons are used to control roll on landing.
What you dont want is outboard ailerons only to droop causing wash-in, since chord line is now positive Angle of attack compared to rest of wing, and thus tip stall.

A crow set-up is actually extreme wash-out on the ailerons and used for diff purpose!

my 2 cents

Firebee:

Of course it'll fly great without flaps/ailerons/LE flaps (and retracts, smoke, gear doors, lights, moving pilot head, opening canopy, tailhook, etc...) but that takes out half the fun here!

The JR thingee sounds like a good product, but I think I'd personally go for the more programmable radio and be done with it. First, it takes out one more point of failure: say the JR thingee decides to hiccup at the wrong point, instant disaster. Second, I don't think you can EVER have "too much radio" for any airplane. If you don't need the fuctions, don't use them! Sure is nice to have them if you ever *do* need them though....

This post isn't intended to knock anybody's equipment choices, it's just my personal opinion that I like to keep my flight controls as foolproof as possible. Now, that being said, I just may have to get me one of them JR thingee's to do the lights, canopy/lock, tailhook & waving pilot I mentioned earlier!

Bob

Actually, you can only have one kickpoint per channel, so as I read the manual, you can't do what you describe above with the channel expander...

Bob

Bear in mind that there is no Futaba radio with true 9 channels. The best they make is 8 channels plus a retract switch. JR claims 10 channels, though I keep reading that they are not all the same, with perhaps the top 2 channels being of reduced resolution and reduced update rate?

Multiplex makes two different 12 channel radios and Graupner makes a 12 channel radio. Robbe also make a 12 channel but I doubt that is available at all in the USA.

The Multiplex and Graupner are true 12 channels - all the same resolution and update rate, so all 12 channels are suitable for primary flying controls. Multiplex uses a crude form of data time compression in the Tx and expansion in their 12 channel Rx in order to speed up data transmission so that the refresh rate is similar to a 9 channel. Graupner has a slower refresh rate.

This means that Multiplex or Graupner give you 50% more true proportional channels than Futaba, which is a serious point for jet flyers.

Multiplex makes the 12 channel Profi 4000 and the 12 channel Royal Evo. For programmability the 4000 is rivalled only by the Graupner MC24, both those radios are way out ahead of Futaba or JR. The Mpx Royal Evo's programmability is somewhere in between the Futaba 9C and 9Z, though some of its features are arguably ahead of the 9Z.

To the person who asked about delaying the move of a locking pin, yes the Mpx 4000 will do that, the 4000 has time controls at 3 different stages in the programming process. I am able to do all the gear and door sequencing inside my 4000, I don't need to fit sequencers inside the model.

Harry

Refresh rate is halved for two of the channels, but all 10 channels are 1024 bits.

Gordon

Harry,
The only problem with the Multiplex/Graupner radios is you feel like your flying with a pizza box. For those who dont fly with trays, the multiplex is very awkward/uncomfortable to handle. Make a multiplex radio in a asian style ergonomic radio case and I would buy one in a second.....! Till then i'll suffer with 9 channels

Todd

Todd,
I can only speak for Multiplex, I sold my 3030 to a buddy of mine and he doesn't fly tray style like I do. He simply uses a neck strap and the radio is balanced perfectly. I flew it that way for him and aside from the "Pizza Box look" it feels very comfortable. So have a try at it you would be very surprised.

Ditto... and that means more than just rounding the corners a bit - i.e. also spreading the controls around a bit more .... with sliders on the sides of the radio where I can reach 'em easily rather than slap in the middle of the TX face where I am expected to take my fingers off of the primary controls (sticks) in order to be able to move the flaps, brakes, etc. There's no way I'm gonna do that on finals on a gusty day !

Until the above dream comes true (which I hope will be someday soon), I'll just muddle along with my 10X & Wc2.

Gordon

Hi,

How are you planning to power your Hornet?

Hey Shaun this is Alan, I sent you an email about a price list on all the jet aircraft.

Can you send me one, there is potentially 2 planes and 2 engines that will be purchase.

ALAN

Alan,

Give me a fax number I can fax you one. I'm at work now, where my pricelist is :-) By the way, your avatar looks like my Falcon landings at San Jose!

Shaun I sent you a PM with the info.

ALAN

I will power the f-18 with 2 of these super 66's

http://www.mooresturbines.com/Engines.asp

any suggestions from you hifh timers

Then,

I'd give some strong consideration to forgetting about the LE flaps. The discussion about whether or not they represent more risk than benefit is a valid one, but, leaving that aside, if you utilize them, you're back to the front spar having only four inches of penetration into the wing. That's fine for the twin hornet flying on a pair of O.S. .65s or .77s, but not twin turbine power. The kit update that happened in '96 or '97 included spars that extend into the wing about 10" and 14", front and back respectively. Just my $.02.

The kit I'm getting is the new carbon one, are you saying that this one has the spars extended? This is good then. Lets assume I'm going to do it...better yet lets say you decide to do it. What modifications would you make (don't worry I would never hold anyone acountable for anything said here) I'll take any ideas anyone has on setting this up. I could order a set of wing cores from yellow with the skins detatched so I can mod the wing to make it stronger... go...lemme have it

Well,

On the kit you're getting, the forward spar goes almost entirely to the leading edge cap. I wouldn't weight the thing down with a bunch of reinforcements to make it suitable for your powerplant. The rear spar is too far aft to carry the whole load like in the F-15s that are out these days.

Why weaken the wing? I know it looks cool, but I think the net effect isn't going to be worth the peace of mind you lose. Again, just my $.02.