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

[Hugh Wiedman]

I don't know much about the AR637T radio and the AS3X. I have something similar in my E Flite P-51. Do you think this receiver could help the F-18 fly better than it did last weekend?

Thanks,

Dave

IMO, the Hornet would be one that would benefit from a gyro, but then I'm one of those that have a gyro in every one of my aircraft, including my 3D aerobatic planes, so maybe I'm just spoiled. The spectrum RX's are nice, but then the AS3X RX's aren't cheap either. Started out with the older AR636's and now use the newer AR637T and higher channel receivers. These latest RX's are much easier to program directly from a Spektrum TX than the older 636's that needed a phone app. They also have some other nice features like being able to increase/decrease gains in flight with a twist of a knob and an included flight pack battery voltage wire you connect to the power leads that allows you to set alarms on your TX when the battery voltage reaches a predetermined low voltage while flying, thus giving you a heads up as to when you need to get on the ground. I still use a timer, but the fail safe is the actual flight pack voltage call outs the TX gives you while flying. You can also set up at least 3 different sets of gains in 3 flight modes, so I like to tie that to the flap switch so gains are around 40-50% when flying flaps up, but much higher like 70-90% when flaps are extended for take-off and especially landing, when you theoretically are going slower and want it as stable as possible. You can/should also set a flight mode with the gyro off. I'm even using the 10 channel AS3X in the Mig 29 for stabilization on the control surfaces and a 2nd Hobby Eagle gyro just for the TV nozzles, so that's how gyro "infected" I am. Additionally, a flying buddy who's a good pilot also programs in SAFE on all his aircraft that allows him to flip a switch and the aircraft immediately levels itself (no matter what insanity he's gotten the aircraft orientation in). He'll even use SAFE while landing. I've yet to go that far and don't program in SAFE, but does sound like a nice emergency option.

With that said, a gyro on a calm day doesn't necessarily add a lot (except maybe the SAFE feature if you get in a bad orientation all on your own). The condition you have of requiring massive left aileron trim to get it to fly level is another issue that's more concerning. A gyro may "ease the pain" of that slightly, but won't solve it as you still need to get it trimmed correctly. I would image that with that much trim, sitting on the ground the ailerons are no where near level when the sticks are nuetral. If it's not the flaps, is it possible the elevators are not symmetrical? I know that's a stupid question as no doubt you took great care in setting up the surfaces to begin with, but at this point (unless it's the missiles), I'm out of ideas.

[Evan D]

Older gyros usually had instructions to be mounted near the CG but that was years ago and it's very rare to see that in instructions. Simply, newer electronic gyros can be placed pretty much anywhere and many can be placed in multiple attitudes.

[davegee]

I can't tell you how many people show up for a maiden and have the stabs, especially full flying at slightly different angles, many many.... Same with different flap angles at various settings. Last, the wing tip sidewinders are flying surfaces and I have seen where they are at different angles of the bayonet lugs are loose and they end up being sloppy and move around in flight. Also some (many FW ones) have thin plastic fins that can warp or move in flight from the air flow.

Lack of power, I always have to ask if the ESC was calibrated.

Gyros don't need to be on the CG.

I started the post and was distracted by a text from my sister and just saw the other replies. On this the flaps up is not all the way to the stops so even at flaps up there could be differences...

Thanks for that great info, Evan. I was very careful to make sure all control surfaces were aligned per the manual. I checked them again and again for weeks before the maiden, and had the pilot check them, too. Having said that, I suppose it is possible that I didn't have something aligned perfectly. But on other planes that I have put together and done the maiden myself in the past, there were only a few clicks here or there to have it fly true.

I did calibrate the ESC during the setup and did test it several times, statically through the whole power range. I wasn't at the controls for the maiden, but I didn't notice a lack of power, other than the fact that we were flying at 5000 feet MSL. But I have little experience flying at lower elevations, so I don't have much to compare it to. The pilot normally flies very fast turbine jet models, so to him, I'm sure it probably looked like it was dogging it.

Next flight I'll fly clean, just incase something was misaligned on the missiles on the wingtips or the pylons under the wings, taken from an ordnance package from the 90 mm F-16 that some people use to accessorize the plane.

Appreciate your comment on the fact that the gyro doesn't have to be positioned on the CG. I thought for sure that I had read that someplace, but when I looked at the instruction sheet for the Freewing gyro that i have, there is no mention of that. I must have been mistaken, and it will make it easier to place it properly some other place on the airplane, per the instructions.

Obviously, I'll recheck every control surface position again to be sure that they were set properly and symmetrically. I did set the flaps up neutral position per the manual, and the elevator setting per the manual for flaps up, takeoff flaps, and landing flaps. But will still double check and adjust, if necessary.

Appreciate your comments.

Best,

Davegee

[Evan D]

I can't tell you how many people show up for a maiden and have the stabs, especially full flying at slightly different angles, many many.... Same with different flap angles at various settings. Last, the wing tip sidewinders are flying surfaces and I have seen where they are at different angles of the bayonet lugs are loose and they end up being sloppy and move around in flight. Also some (many FW ones) have thin plastic fins that can warp or move in flight from the air flow.

Lack of power, I always have to ask if the ESC was calibrated.

Gyros don't need to be on the CG.

I started the post and was distracted by a text from my sister and just saw the other replies. On this the flaps up is not all the way to the stops so even at flaps up there could be differences...

[davegee]

Thanks, Hugh. The pilot elected to do the takeoff "Flaps Up" so I think we can assume that flaps didn't play into the equation of having so much aileron and rudder trim. It was unsettling how it was so difficult to handle in the air, especially since both of us were fairly confident it would fly well. It was a real handful and he was lucky to bring it down in one piece.

I have the 3672-1900 9-bladed inrunner in my airplane, which should give it plenty of power. In the past, I have found some disappointment flying at 5-6000 feet MSL versus flight at sea level. I don't know how much this one was degraded by the altitude at this point. But most of my experience is at 5000+ feet runways, so I'm not sure how to compare the performance of the two at sea level or at 5000 feet. I do know, for what it's worth, in my career flying heavy jet transport category aircraft, the performance was huge between sea level and hi altitude airports. I suspect there is some correlation with model airplanes, too.

I don't know much about the AR637T radio and the AS3X. I have something similar in my E Flite P-51. Do you think this receiver could help the F-18 fly better than it did last weekend?

Thanks,

Dave

[Hugh Wiedman]

I took my Freewing F-18C up for its maiden the other day. I had one of the guys in our club, a much better pilot than me who also flies turbine jets, at the controls for this first flight. It took off normally but veered to the right some after takeoff. He had difficulty trimming it out in aileron and rudder, having to add a lot of left aileron, and then a lot of left rudder trim to keep it flying straight. He eventually zeroed out the aileron trim before landing, but still kept 56 units of left rudder trim in the Spektrum DX18 I was using. He did not have to trim elevator at all, and it seemed pretty happy at about 96mm.

He got it on the ground safely, but I think it left him and me shaken a bit. We were both expecting a "routine" maiden of this airplane. I have had a couple of these before, and never had these control issues.

Here are a few thoughts and/or recommendations:

1) All control surfaces were checked and rechecked by me before the flight and both of us after the flight. They were all in the exact positions that they should be per the book, no mis- alignments side to side.

2) I did add a couple of Sidewinder missiles on the wingtips and two empty pylons (from a 90mm F-16 model) on the wings. I have heard someone having issues putting on wing pylons or missiles and then having control issues with the plane in flight. Not sure if this had any issue on the flight, but will fly the next one clean.

3) The pilot complained about a lack of power on the airplane. Could be partly to the fact we are at 5,000' MSL, but also a possibility(?) is that the modified ESC wiring cables could have had something to do with it. Just a guess. I had to splice in about 4 inches of 10 gauge wire as they were too short (coming from a F-15 model). I have ordered a new wiring harness from MRC specifically designed for the F-18.

4) Last, I have no gyro in it yet. Seems to me the space is too tight to ever get it that far back in the fuselage to be near the CG. I'm wondering if another receiver/gyro stabilizer is available that might dampen out minor excursions in its flight. Any recommendations?

Appreciate any thoughts on this. I would really like to get this plane dialed in to fly again. Not very confident putting it up again until it looks like these maiden flight issues have been handled.

Thanks,

davegee

Dave,

Just a few thoughts.

1) Not sure what caused the need for so much left aileron trim. On both my Hornets, with missiles on the wingtips (but no pylons under the wing), I ended up with 5 clicks (+10) and 6 clicks (+12) of RIGHT aileron trim from starting with all surfaces level. I would normally say that one of the flaps (left flap) might not have retracted after take-off, but I'm sure you watched that carefully. It is possible that it did not retract in the air, although on the ground worked perfectly. That's what both mine did on each Hornet, the only difference was they retracted fine after take-off, but one would not deflect again when getting ready to land. The only way I knew was I had to do a relatively slow flyby to visually see if they were both down in the same position and noticed that they were not. First time it happened, I had to trim about that same amount, 56 units, to get it flying level. On the ground, they worked perfectly so the aileron trim was way off next time up if they both worked fine.

2) Surprised the pilot felt it had a lack of power, even at 5,000 feet. Do you notice a problem with other EDF's at the same altitude? I seem to recall that you installed the 12 blade 1835 Kv inrunner, no? Even with the 9 blade stock it should be fine. Put a power draw meter on it. You should be drawing about 127 Amps and about 3100 watts at full throttle, for 6-7 seconds on a fully charged battery. That's what I'm getting on the SMC 6200 mah 40C. On a Roaring Top 5500 70C (actual C more like 32C), it was getting about 120 amps and 2800 watts. I had a friend who got one of the BA Hornets early on and after some 150 flights, he was always complaining that he could use more thrust. I let him fly mine with the 12 blade inrunner and he promptly upgraded it. First flight out he called me and said this fan's not much better. I asked him to put his power meter on and it came back at about 65-70 Amps, full throttle, fully charged battery. He found that he TX had some tricky issue going on with calibrating his ESC (forgot what kind, but not a Spektrum) and once he recalibrated the ESC, he was ecstatic. Turns out he'd been flying it for 2 years, over 150 flights, never getting more that 56-70% throttle.

3) In both my Hornets, I'm using the AR637T RX with AS3X. Initially located it in the back, then after several (I think it was probably Air Guardian) in this forum suggested I relocate it under the battery tray, I did. It now sits completely UNDER the battery tray as far forward as possible with the 2 antennae coming out and going way up in the nose. All wires (except the power cord and BEC wires) are out of the way under the battery tray so it makes for a clean set-up and I can put the battery anywhere I want to. Also added a remote satellite that goes all the way back in the front fuselage at the foam divider. I now try to do that in all these aircraft. It was a real space saver in the Mig, although with all the extra wires for AB's, TV nozzle wires and 2nd gyro for the TV's, it was a real tight fit to get everything under the back tray, but keeps it real clean.

[davegee]

I took my Freewing F-18C up for its maiden the other day. I had one of the guys in our club, a much better pilot than me who also flies turbine jets, at the controls for this first flight. It took off normally but veered to the right some after takeoff. He had difficulty trimming it out in aileron and rudder, having to add a lot of left aileron, and then a lot of left rudder trim to keep it flying straight. He eventually zeroed out the aileron trim before landing, but still kept 56 units of left rudder trim in the Spektrum DX18 I was using. He did not have to trim elevator at all, and it seemed pretty happy at about 96mm.

He got it on the ground safely, but I think it left him and me shaken a bit. We were both expecting a "routine" maiden of this airplane. I have had a couple of these before, and never had these control issues.

Here are a few thoughts and/or recommendations:

1) All control surfaces were checked and rechecked by me before the flight and both of us after the flight. They were all in the exact positions that they should be per the book, no mis- alignments side to side.

2) I did add a couple of Sidewinder missiles on the wingtips and two empty pylons (from a 90mm F-16 model) on the wings. I have heard someone having issues putting on wing pylons or missiles and then having control issues with the plane in flight. Not sure if this had any issue on the flight, but will fly the next one clean.

3) The pilot complained about a lack of power on the airplane. Could be partly to the fact we are at 5,000' MSL, but also a possibility(?) is that the modified ESC wiring cables could have had something to do with it. Just a guess. I had to splice in about 4 inches of 10 gauge wire as they were too short (coming from a F-15 model). I have ordered a new wiring harness from MRC specifically designed for the F-18.

4) Last, I have no gyro in it yet. Seems to me the space is too tight to ever get it that far back in the fuselage to be near the CG. I'm wondering if another receiver/gyro stabilizer is available that might dampen out minor excursions in its flight. Any recommendations?

Appreciate any thoughts on this. I would really like to get this plane dialed in to fly again. Not very confident putting it up again until it looks like these maiden flight issues have been handled.

Thanks,

davegee

[davegee]

Won't get far in this year's March Mayhem (I always crash and burn in the first round) with the F-18 Tiger Meet, but I did get this Hornet into April's 2022 edition of Model Aviation under the Focal Point section. Have no idea who submitted it last October, so thanks for that. OK, I admit, I'm just a shameless publicity hound!

I just saw that, Hugh. Looks great! Congrats on getting it published in Model Aviation magazine. Always one of my favorite sections of the magazine each issue, Focalpoint.

Cheers

davegee

[Hugh Wiedman]

Won't get far in this year's March Mayhem (I always crash and burn in the first round) with the F-18 Tiger Meet, but I did get this Hornet into April's 2022 edition of Model Aviation under the Focal Point section. Have no idea who submitted it last October, so thanks for that. OK, I admit, I'm just a shameless publicity hound!

[davegee]

https://www.youtube.com/watch?v=-w7oc0LczBE


Hey Hornet Honchos, Check out this great Blue Angels Walkaround ewe-toob vid by Erik Johnston's Crew.

Former Navy F-18 and Blue's pilot (#'s 3&4 slots) Jerry Deren does the narration.

The airframe is located at Frontiers of Flight Museum in Dallas at Love Field.

Enjoy. Best, Steve

Thanks so much for posting that, Steve. Very informative from a guy who has "been there, done that" and conveys his extensive experience very well to the viewer. I also like the video with clear details of the aircraft which are very helpful as reference tools for making add-on or scratchbuilt mods to our models for greater realism.

Cheers

Dave

[Elbee]

https://www.youtube.com/watch?v=-w7oc0LczBE

Hey Hornet Honchos, Check out this great Blue Angels Walkaround ewe-toob vid by Erik Johnston's Crew.

Former Navy F-18 and Blue's pilot (#'s 3&4 slots) Jerry Deren does the narration.

The airframe is located at Frontiers of Flight Museum in Dallas at Love Field.

Enjoy. Best, Steve

[Elbee]

Thanks, Steve. Again, Excellent design work on your part for the cockpit of the F-18, and of course the Corsair, too.

Me, either. With that thinking, we should embrace the name "Brown Angels" demonstration team, or something like that!

Hah, draw it up and I'll get with Callie. Let's just start a "new" squadron of "ole" Legacy Hornets. We need a mascot and livery for a vertical stab design. This could be 'most excellent'. Best, Steve

[davegee]

Excellent work davegee!

Thanks, Aros. The key was the outstanding STL files from Elbee!!

Dave

[davegee]

Nice Work Dave Gee!! Bravo Zulu. Acknowledged and Agreed with the "whole different subject." Cannot for the life of me get my head around that decision. Anywho, ya dun gud, Sir. Best, Steve

Thanks, Steve. Again, Excellent design work on your part for the cockpit of the F-18, and of course the Corsair, too.

Me, either. With that thinking, we should embrace the name "Brown Angels" demonstration team, or something like that!

[Gilatrout]

EJECT! EJECT! EJECT!

[Elbee]

...painted him up yesterday and the helmet reflects the markings I found online of a VFA-146 "Blue Diamonds" helmet. Notice I didn't say "Gray Diamonds" but that's a whole different subject! I'll attach some pics I just took of the finished pilot in the cockpit.

Nice Work Dave Gee!! Bravo Zulu. Acknowledged and Agreed with the "whole different subject." Cannot for the life of me get my head around that decision. Anywho, ya dun gud, Sir. Best, Steve

[Aros]

Excellent work davegee!

[davegee]

Sounds good, I'm sure the maiden will go well and the balance point of 97mm should be a good place to start. I also think I have a little more tail weight since both of mine have the 12 blade 1835Kv inrunner which is a bit heavier than the 9 blade inrunner, allowing me to use a 6200 mAh battery. You won't get as much thrust from the Admiral or Spektrum battery as you would from the SMC's I'm using (true C close to 40) as their true C is more like 18 to 22 C despite what it's marked at, but should still be enough.

The only thing to potentially watch for is one of the flaps not deploying in flight. It seems to be quite rare, but both of mine had that issue, lucky me. Flaps work fine on the ground (even if you hold them to see of the servo quits), but for some reason, occasionally one will get stuck in the up position in flight (and for me it's not always the same one). They go from take-off flaps to flaps up when taking off fine, but then when setting up to land, sometimes one does not deflect at all. I've tried a bunch of things to cure it, including bypassing the blue box /circuit board for both ailerons and flaps going directly into the receiver. Worked better for a while, then occasionally didn't. I've replaced flap servos and reduced the delay to 0, still hasn't completely cured it (although it hasn't happened for a while on either). With the delay at 0 and on one occasion, went from flaps up directly to landing flaps and it immediately got incredibly difficult to control and damn near totaled it (saved by 12 foot high cane giving it a soft set down). I'm currently using a 1.5 second delay and always come by first with 1/2 flaps to visually confirm both are working before going to full flaps. Have this same issue on both B-24's and my Avanti and going to a 0-1 second delay has cured it for good on those, but still a little concerned on both Hornets, so just let him know of the potential issue and being ready to raise flaps quickly if it happens. With that said, I'm sure the probability of yours having this problem is extremely low.

Thanks for those valuable tips, Hugh. Yes, the possibility of an asymmetrical flap problem is a concern for me, especially on a pretty hot performer like the Hornet. I'll be sure to brief whoever does the maiden for me when we get to that point. I've had a number of weird asymmetrical flap issues on various airplanes, mostly props, but fortunately not too much in the jets that I have flown. But I'm always on the lookout for them coming up. I had a weird one years ago on the maiden of my Flightline Spitfire (the big one) when either flap would come down, uncommanded and then go back up again, on its own. We were lucky to get it down safely. I reported it to MRC, and they told me there were a handful of people complaining about the same thing. They gave me two new flap servos, and that was over 5 years ago. Haven't had it recur...yet!

Dave

[Hugh Wiedman]

Thanks for the info, Hugh. On my stock airplane with the stock cockpit (for now) I am getting about 97mm or so on the CG using a 5000 mAh Admiral or Spektrum smart battery. I am hoping to do the maiden in a few weeks. Since I have lost a couple of these planes in the past I am going to have one of our jet experts in our club to to the maiden for me while I observe and help out if he needs me to by adjusting trim or whatever. Still windy and chilly up here, but Spring is definitely approaching!

Sounds good, I'm sure the maiden will go well and the balance point of 97mm should be a good place to start. I also think I have a little more tail weight since both of mine have the 12 blade 1835Kv inrunner which is a bit heavier than the 9 blade inrunner, allowing me to use a 6200 mAh battery. You won't get as much thrust from the Admiral or Spektrum battery as you would from the SMC's I'm using (true C close to 40) as their true C is more like 18 to 22 C despite what it's marked at, but should still be enough.

The only thing to potentially watch for is one of the flaps not deploying in flight. It seems to be quite rare, but both of mine had that issue, lucky me. Flaps work fine on the ground (even if you hold them to see of the servo quits), but for some reason, occasionally one will get stuck in the up position in flight (and for me it's not always the same one). They go from take-off flaps to flaps up when taking off fine, but then when setting up to land, sometimes one does not deflect at all. I've tried a bunch of things to cure it, including bypassing the blue box /circuit board for both ailerons and flaps going directly into the receiver. Worked better for a while, then occasionally didn't. I've replaced flap servos and reduced the delay to 0, still hasn't completely cured it (although it hasn't happened for a while on either). With the delay at 0 and on one occasion, went from flaps up directly to landing flaps and it immediately got incredibly difficult to control and damn near totaled it (saved by 12 foot high cane giving it a soft set down). I'm currently using a 1.5 second delay and always come by first with 1/2 flaps to visually confirm both are working before going to full flaps. Have this same issue on both B-24's and my Avanti and going to a 0-1 second delay has cured it for good on those, but still a little concerned on both Hornets, so just let him know of the potential issue and being ready to raise flaps quickly if it happens. With that said, I'm sure the probability of yours having this problem is extremely low.

[davegee]

Now that I see your pilot, yes it is a different one than what I used. Better than the shoulder/head pilot it comes with. I've got several of the same pilot you used in my "pilot inventory" and it is a FW pilot but can't remember what aircraft they came in. The one I used in the Tiger Hornet has moveable arms, but those stupid gloves are annoying.

Regarding the CG, on the Hornet with the 3D cockpit I think I put 3/4 ounce in each elevator bay. That, along with a little weight for the afterburner allowed me to achieve a maximum rearward CG of 105mm with a 6200 weighing 814 gr. I also put all electronics, RX and wires under the battery tray so I could move the battery as far back as possible. The RX is under the front part of the tray (away from the battery and cables) with the antennae going up to the nose and a remote satellite is all the way in the back of the tray with antennae going around the fuselage. In the Tiger Hornet, I set it up the same with electronics and RX, but am able to get to 112mm (not that I want to) with no lead in the elevator bay. Currently flying both at 102mm.

Your cockpit is outstanding and the scheme on his helmet is so realistic. Can't wait to see the finished product!

Thanks for the info, Hugh. On my stock airplane with the stock cockpit (for now) I am getting about 97mm or so on the CG using a 5000 mAh Admiral or Spektrum smart battery. I am hoping to do the maiden in a few weeks. Since I have lost a couple of these planes in the past I am going to have one of our jet experts in our club to to the maiden for me while I observe and help out if he needs me to by adjusting trim or whatever. Still windy and chilly up here, but Spring is definitely approaching!