Official Freewing F/A-18C Hornet 90mm EDF Thread

[Evan D]

Yes you moved the clevis on the ailerons. Look at the second picture and see how the outer hole is larger? Using the clevis in this larger hole causes slop. Is that the slop you were asking about earlier saying you wanted to fill in the hole and redrill?

I am familiar with this set up and it works surprisingly well. It’s obviously not a way to rig a 3D airplane but…

[jasmith41]

But your clevis links are loose on your F-8?

Can you post a picture?

In case you're not familiar with this model, there are only two servos - one on each side that control both aileron and elevator. Plane is set up as with elevons / tailerons. Was really odd for me with this one when just starting out because i have no other birds set up this way, but i think i've got my head around it - other than minor tweaks like this issue. The mudduck has one as well and he's set his ailerons to move as little as possible. I'm may have moved my ailerons down one from the book set up, but they were just as loose in the old setting.

[jasmith41]

But your clevis links are loose on your F-8?

Can you post a picture?

yes and yes - later...
push rods are so small, i'm not sure there are ball links to fit them...

[Evan D]

But your clevis links are loose on your F-8?

Can you post a picture?

[jasmith41]

Look at the instruction manual...

It's set-up per the manual, same as i do with all planes.

[Evan D]

Look at the instruction manual...

[Evan D]

I'm not saying that. I'm saying that the holes in the horns are different sizes and you use the smaller holes if using clevis's. Using the proper holes, per the instructions you shouldn't have any play.

[jasmith41]

JA, look closely at those horns and you'll find the outermost hole larger than the others. It is designed for a ball to be screwed there for planes that use ball links. On most of the FW planes they tell you to use the middle hole if using clevis links. Look at the instructions closely.

yeah - switching the ailerons to ball-links - most logical thing to do. The style Hugh is showing i have on all the other FW planes, but this little F8 has the traditional 'clevis' design. Switching them all is the way to go to eliminate that as the cause of the weird movements while flying.

[Evan D]

JA, look closely at those horns and you'll find the outermost hole larger than the others. It is designed for a ball to be screwed there for planes that use ball links. On most of the FW planes they tell you to use the middle hole if using clevis links. Look at the instructions closely.

[Hugh Wiedman]

It seems like the clevis pin is pretty loose in the arm coming off the wing. Should i glue the hole shut and re-drill it with a smaller hole...? or are there known tricks...? none of the clevises i have are any larger pin-wise... and these are pretty small since it's a very small plane...

I'm sure there are some tricks for those small clevises but I don't have any myself. I use ball links on all my control rods to reduce the play from using those plastic clevises. I also put rubber tubing on any clevises (like those usually found on gear doors) and the horns on the servos.

[jasmith41]

That should work better on the knob, start at 100% and then dial it down until the oscillation is gone. The only bad part about the gains being on one knob, is as you dial it down, all three go down at the same time. If you have enough channels in your TX, the ultimate way to do it is have each of the 3 surfaces on a separate wheel and you can dial each one down as needed. I don't do that (although that's how the HH technicians determine just how much gain each surface needs on a new model). Don't have enough channels and man, that's a lot to think about and fiddle with while you're flying, way to much for me just trying to keep it in one piece. A flying buddy has that, but my brain/fingers are way too far gone to take that step. After you get it flying with no oscillations, then go back to fixed gains so you don't have to worry about inadvertently changing the knob or having it at the wrong place for each model.

If you're hands shake a bit, like mine (had it all my life, which is the only reason I'm not a brain surgeon and the more nervous I get the worse), I would try just a bit more expo. You do loose a bit of the sensitivity, but it may also take out any hand shakes. I use about 25-30%, which is substantial, and the expert pilots I know like to use 10-15% max when flying my aircraft. My 3D aircraft on extreme high rates use expos of 70%, which is actually recommended by the Extreme Flight manuals. It sort of acts like low rates with minimal stick movements, but then transitions into high rates as you increase the stick movements.

Thanks again - i was thinking the same about all 3 gain levels moving if on one knob. I've got two open knobs and two open sliders on the ix20, so can split them up accordingly... I may try setting them all lower and adjusting from one knob, turning up the expo and see what happens. The porpoising on the F5 is real subtle, but it's there. The F8 is another story. How would you fix the loose linkage issue? It seems like the clevis pin is pretty loose in the arm coming off the wing. Should i glue the hole shut and re-drill it with a smaller hole...? or are there known tricks...? none of the clevises i have are any larger pin-wise... and these are pretty small since it's a very small plane...

[Hugh Wiedman]

Thanks Hugh - you confirmed what i thought i knew - lower gain was better for these edfs that go fast. On the F8, we determined that there is a lot of play in the aileron linkage i probably still need to fix. I'm also not good at figuring out how much expo I need, so some of he movement may be due to nervous energy (shaking hands) on the stick. The F5 porpoises a bit at high speed, more so than aileron rolling back and forth. Yes, i can put the gain on the knob. had it that way at first and then locked them in to see if i could adjust it out, but sounds like i need to put them both back on the knob and try that again. Thanks again. I appreciate it.

That should work better on the knob, start at 100% and then dial it down until the oscillation is gone. The only bad part about the gains being on one knob, is as you dial it down, all three go down at the same time. If you have enough channels in your TX, the ultimate way to do it is have each of the 3 surfaces on a separate wheel and you can dial each one down as needed. I don't do that (although that's how the HH technicians determine just how much gain each surface needs on a new model). Don't have enough channels and man, that's a lot to think about and fiddle with while you're flying, way to much for me just trying to keep it in one piece. A flying buddy has that, but my brain/fingers are way too far gone to take that step. After you get it flying with no oscillations, then go back to fixed gains so you don't have to worry about inadvertently changing the knob or having it at the wrong place for each model.

If you're hands shake a bit, like mine (had it all my life, which is the only reason I'm not a brain surgeon and the more nervous I get the worse), I would try just a bit more expo. You do loose a bit of the sensitivity, but it may also take out any hand shakes. I use about 25-30%, which is substantial, and the expert pilots I know like to use 10-15% max when flying my aircraft. My 3D aircraft on extreme high rates use expos of 70%, which is actually recommended by the Extreme Flight manuals. It sort of acts like low rates with minimal stick movements, but then transitions into high rates as you increase the stick movements.

[jasmith41]

If you're getting oscillations, the gains are too high. First you'll need to determine which surface is oscillating, most likely it will be the ailerons as I've found those oscillate before the elevator and lastly the rudder. Gyro oscillation on the ailerons makes it waggle rolling left right and gets worse the faster you go. Since you said the gains are fixed and not adjustable, I assume you are not able to put gains on a TX knob to adjust in the air, which is not a problem. As I said, the oscillation will occur the faster the plane goes, so when it oscillates, if you slow down it should cease. If it oscillates at all speeds, then the gyro may not be the issue (loose control horns/rod/servo or even a bad servo). I would change the gains to 15/20/20, assuming it is the aileron surface and it only happens at higher speeds. Generally, the faster the aircraft and the larger the control surfaces will require lower gain settings. I'm kind of surprised you're getting oscillations at what I would consider low gain settings (is this on a spektrum RX or with a stand alone gyro) since I'm using at least double that on all my EDFs with no oscillations. I even have the spektrum RX's in my 60" Extreme Flight planes which have extremely large control surfaces, but with those I am flying a lot slower than an EDF and use gains in the 25% range, except in some stall mode settings with gains up to 70%, but then the aircraft is really not moving. Dial down the gains (only on the oscillating surface first), take it up and see how it goes.

Thanks Hugh - you confirmed what i thought i knew - lower gain was better for these edfs that go fast. On the F8, we determined that there is a lot of play in the aileron linkage i probably still need to fix. I'm also not good at figuring out how much expo I need, so some of he movement may be due to nervous energy (shaking hands) on the stick. The F5 porpoises a bit at high speed, more so than aileron rolling back and forth. Yes, i can put the gain on the knob. had it that way at first and then locked them in to see if i could adjust it out, but sounds like i need to put them both back on the knob and try that again. Thanks again. I appreciate it.

[rcflyerct]

Wes,
I'm only using sensitivity of 1, not that sophisticated to use anything else. I also use priorities of 150. Currently using the following gains on the AR637T (rate only, no heading and haven't used SAFE, not that there is anything wrong with it, just have never set it up-although a flying buddy who is a great pilot uses it for any emergency situations and on landing, so may have to give it a try one day) and those gains are (R/P/Y) with flaps up 45/50/55 and on take-off flaps 60/70/80 and landing flaps 70/80/90, 3 rate profiles tied to flap switch and gain adjust in flight set to TX knob H at 100% so I can turn it down if needed, but have never had any oscillations there. Rarely flying full throttle for a high speed pass so I'm rarely at the top end of the speed envelope to experience any oscillations.

Thanks!!!

[Hugh Wiedman]

Hugh, I'm getting some oscillation on a couple of my EDFs (80mm F5 and small F8 Corsair Freewings), i probably have my gains set (fixed) at 20/20/20. Would you suggest increasing them to reduce / eliminate that? I don't really understand this all that well yet and appreciate your input...
I know you've written extensively lately on this topic so I apologize for the redundant question, but I"m gathering from your writing that my settings are too low... possibly correct...?

If you're getting oscillations, the gains are too high. First you'll need to determine which surface is oscillating, most likely it will be the ailerons as I've found those oscillate before the elevator and lastly the rudder. Gyro oscillation on the ailerons makes it waggle rolling left right and gets worse the faster you go. Since you said the gains are fixed and not adjustable, I assume you are not able to put gains on a TX knob to adjust in the air, which is not a problem. As I said, the oscillation will occur the faster the plane goes, so when it oscillates, if you slow down it should cease. If it oscillates at all speeds, then the gyro may not be the issue (loose control horns/rod/servo or even a bad servo). I would change the gains to 15/20/20, assuming it is the aileron surface and it only happens at higher speeds. Generally, the faster the aircraft and the larger the control surfaces will require lower gain settings. I'm kind of surprised you're getting oscillations at what I would consider low gain settings (is this on a spektrum RX or with a stand alone gyro) since I'm using at least double that on all my EDFs with no oscillations. I even have the spektrum RX's in my 60" Extreme Flight planes which have extremely large control surfaces, but with those I am flying a lot slower than an EDF and use gains in the 25% range, except in some stall mode settings with gains up to 70%, but then the aircraft is really not moving. Dial down the gains (only on the oscillating surface first), take it up and see how it goes.

[jasmith41]

Wes,
I'm only using sensitivity of 1, not that sophisticated to use anything else. I also use priorities of 150. Currently using the following gains on the AR637T (rate only, no heading and haven't used SAFE, not that there is anything wrong with it, just have never set it up-although a flying buddy who is a great pilot uses it for any emergency situations and on landing, so may have to give it a try one day) and those gains are (R/P/Y) with flaps up 45/50/55 and on take-off flaps 60/70/80 and landing flaps 70/80/90, 3 rate profiles tied to flap switch and gain adjust in flight set to TX knob H at 100% so I can turn it down if needed, but have never had any oscillations there. Rarely flying full throttle for a high speed pass so I'm rarely at the top end of the speed envelope to experience any oscillations.

Hugh, I'm getting some oscillation on a couple of my EDFs (80mm F5 and small F8 Corsair Freewings), i probably have my gains set (fixed) at 20/20/20. Would you suggest increasing them to reduce / eliminate that? I don't really understand this all that well yet and appreciate your input...
I know you've written extensively lately on this topic so I apologize for the redundant question, but I"m gathering from your writing that my settings are too low... possibly correct...?

[Hugh Wiedman]

Hugh...may I ask what AS3X sensitivity you use (1-2 or 4). Thanks!!! Wes

Wes,
I'm only using sensitivity of 1, not that sophisticated to use anything else. I also use priorities of 150. Currently using the following gains on the AR637T (rate only, no heading and haven't used SAFE, not that there is anything wrong with it, just have never set it up-although a flying buddy who is a great pilot uses it for any emergency situations and on landing, so may have to give it a try one day) and those gains are (R/P/Y) with flaps up 45/50/55 and on take-off flaps 60/70/80 and landing flaps 70/80/90, 3 rate profiles tied to flap switch and gain adjust in flight set to TX knob H at 100% so I can turn it down if needed, but have never had any oscillations there. Rarely flying full throttle for a high speed pass so I'm rarely at the top end of the speed envelope to experience any oscillations.

[rcflyerct]

Agree with Dougcarr73 , put the RX under the battery tray and removed the BB so you can place the battery as far aft as you need. The manual CG suggests 88mm, if memory serves me. For me, that's too nose heavy and I prefer it around 100mm back, although some others go to 110m. I'm flying with the SMC 6200 40C packs which weigh in at 814 gr and get 5 minutes of flight time, more if I cruise it lazily around (but what's the fun in that). I also using the AR637T RX in the front under the floor boards and a remote all the way in the back. Gains are relatively higher than I would have initially thought was possible, but it's rock solid. 45/50/55 flaps up, 75/80/85 take-off flaps and 85/90/90 landing flaps. I have 2 F-18's and redid the cockpit with LB's 3D design and added a 1/10 scale full body pilot so my cockpit is about 250 gr heavier than the stock, which required keeping all the electronics out of the way and getting the SMC back far enough to achieve my CG (along with a couple pieces of lead in the elevator bays and the extra weight of the 12 blade inrunner and AB's). But doing that with all the electronics makes for a very nice and clean setup, something I try with every aircraft. Assuming you leave the cockpit stock and don't add any extra weight redoing it, I see no reason why an 870gr 6600 pack wouldn't do nicely.

BTW, 870 gr for a 6600 pack is relatively heavy, what pack are you using. I know the heavier the pack, usually the higher the actual C, but the SMC's test out as one of the highest actual tested C and the 6200 weighs only 814 gr. I also use their 8100 mah 20C packs in my F-16 and those weigh 904 gr and actually test out to 25C (still higher than HRB 50C's, any Admiral 50C, Roaring Top 70C, etc.). I fly off grass so initial thrust is the most important factor for me and even the 8100 on the 12 blade 1835Kv inrunner I have in all my 90mm EDF's pull high enough amps/watts on it to perform quite well.

Hugh...may I ask what AS3X sensitivity you use (1-2 or 4). Thanks!!! Wes

[Elbee]

Just finishing up my paint on my F/A 18

YR, Great livery choice. Is that one of the "Aggressor" Schemes? Nicely done in any case. Best, LB

[yf22raptor]

Just finishing up my paint on my F/A 18
then installing my turbine conversion as well
big boy rc on Facebook sell the conversion kits.