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

[davegee]

After getting my 29th flight (3 on this new airframe with the innards the same on all flights so far) I am now looking out the window at the white stuff coming down. But I'm taking advantage of the down time to work on my AIM-9 Sidewinder missiles that I am learning to 3D print with my Prusa mini. These are from the files of Dirty D in 1/10 scale. So, although maybe slightly larger than scale (1/10 versus 1/11 of the model), that difference is really indistinguishable when they are mounted on the wingtips.

I still have scale nomenclature and markings to put on the missiles that I'll have Callie print up, and then they should basically be finished. I plan on doing some test flights with these missiles mounted next week when the weather gets better.

A Big Shoutout to LB for his continued support of getting me up and running on this new medium of model building!

Davegee

[davegee]

Awesome you figured it out Dave.

Appreciate your excellent advice, as always, Evan! I did check the tightness of the bolt holding on the fan blade. It was not loose, but didn't hurt to tighten in up a bit more. And although there wasn't a piece of plastic loose, which it certainly could have been, that piece totally missing seems to be the culprit and will be corrected on the next flight. I've done a few full power static runups with my replacement piece that I fashioned out o f.010" styrene. So far, so good. We'll see how it fares on the next test flight early next week!

Cheers

Dave

[Evan D]

Awesome you figured it out Dave.

Maybe the fan adapter on the motor shaft is loose?

Also there may be a clear plastic piece where the ESC wires go forward that is moving?

[davegee]

I never had heard that sound before in any EDF jet I’ve owned. I did fly it twice before I found the cause. The motor output power was normal so I just let it rip to see what happened. Now that I’ve fitted at least a temporary plastic shield in there, everything seems to be back to normal. Very weird…

[Hugh Wiedman]

I think I discovered the source of that"pop" sound each time I run up the motor to full power in static test. I ordered some JP brakes for this plane and my Freewing T-33 as they have a propensity to roll out all the way and past the end of the runway into the nasty weeds and rocks. I installed the new JP wheels on the Hornet, and was fishing the electrical line from each brake through the main gear wheel well and through the tunnel to connect up with the brake controller and receiver. One went fine, and then I noticed something "weird" when I was stringing the electrical wire through to the forward part of the fuselage. It turns out that there is a plastic sheet or panel that is glued in the main gear wheel well that helps divert the airflow from the intakes on the fuselage, and these plastic panels apparently keep maybe unstable air from getting sucked in from the bottom of the wheel wells and into the motor intake.

I contacted MRC tech support on this, and the fact that for whatever reason, that plastic panel was never installed on that side. No evidence it had ever been there with a glue line or anything like that. Since this isn't a normal replacement part, they're going to have to search for a trashed airplane fuselage where they can harvest that part, hopefully.

In case they can't find one to send me, I made my own out of a sheet of styrene plastic .010" thick. I got it pretty close and once it is fully dry, I'll do a full power static runup to test it. If they send me the "real" part that I need, I can always pull this one out and put the OEM part in, or just have it for a spare.

Note: I did do a full power static runup late today, and for the first time, I did NOT hear that little momentary "pop" when I ran it up to full power. I'm assuming that the designers at Freewing made these parts for a reason, but when I decided to put my bird up for a couple of flights last week, I did hear that pop, not knowing what caused it. I think when one of those panels is missing, it causes some strange airflow patterns for a second or so rapidly going to full power, and thus the "pop" sound. That's all I can think caused it. I didn't find anything unusual flying the plane on those two test flights, even with that inner panel totally missing from the airplane. But I'm guessing it flies better if both of those panels are securely attached into the main gear wheel well areas to help divert the air from the two intakes on the sides of the fuselage directly into the motor.

Davegee

Sounds (no pun intended) like you found the source of the "sound gremlin". How weird, I'll check mine out next time I take it out.

[davegee]

Question on a small momentary "pop" sound when I do a static runup to full power. I took my new F-18C (with the old motor, ESC, wiring,etc) onboard out to the field to do a full power static runup, run taxi tests, range tests, etc. The wind was too strong a crosswind to hazard taking it up, so I got a lot done on the ground. It is very solid and seems to be ready for a new maiden (even though I got almost 30 flights on it before I "pancaked" it on a botched landing attempt about 6 months ago. That prompted me to just buy a F-18C ARF+and put the undamaged "guts" inside.

Everything was totally normal, except that I could hear a small, momentary "pop" sound when I ran the motor up each time to full power. It almost sounded like a little pop of air, and doesn't seem to come from anywhere back near the motor. Seems to come near the front of the fuselage, although I may be mistaken.

Holding the model by the vertical tail, it has gobs of power and I think the motor is very strong and healthy. But I still get that very momentary "pop" sound and then it goes away.

I'm wondering if anyone has ever had a similar occurrence with an EDF jet. I haven't. I'm still tempted to take it up for a quick flight around the patch later this week, for starters.

Appreciate any comments as to what this might be. Battery is solid and everything seems to be normal, otherwise. I've already pulled the motor cover and it looks to be normal.

Cheers

Davegee

I think I discovered the source of that"pop" sound each time I run up the motor to full power in static test. I ordered some JP brakes for this plane and my Freewing T-33 as they have a propensity to roll out all the way and past the end of the runway into the nasty weeds and rocks. I installed the new JP wheels on the Hornet, and was fishing the electrical line from each brake through the main gear wheel well and through the tunnel to connect up with the brake controller and receiver. One went fine, and then I noticed something "weird" when I was stringing the electrical wire through to the forward part of the fuselage. It turns out that there is a plastic sheet or panel that is glued in the main gear wheel well that helps divert the airflow from the intakes on the fuselage, and these plastic panels apparently keep maybe unstable air from getting sucked in from the bottom of the wheel wells and into the motor intake.

I contacted MRC tech support on this, and the fact that for whatever reason, that plastic panel was never installed on that side. No evidence it had ever been there with a glue line or anything like that. Since this isn't a normal replacement part, they're going to have to search for a trashed airplane fuselage where they can harvest that part, hopefully.

In case they can't find one to send me, I made my own out of a sheet of styrene plastic .010" thick. I got it pretty close and once it is fully dry, I'll do a full power static runup to test it. If they send me the "real" part that I need, I can always pull this one out and put the OEM part in, or just have it for a spare.

Note: I did do a full power static runup late today, and for the first time, I did NOT hear that little momentary "pop" when I ran it up to full power. I'm assuming that the designers at Freewing made these parts for a reason, but when I decided to put my bird up for a couple of flights last week, I did hear that pop, not knowing what caused it. I think when one of those panels is missing, it causes some strange airflow patterns for a second or so rapidly going to full power, and thus the "pop" sound. That's all I can think caused it. I didn't find anything unusual flying the plane on those two test flights, even with that inner panel totally missing from the airplane. But I'm guessing it flies better if both of those panels are securely attached into the main gear wheel well areas to help divert the air from the two intakes on the sides of the fuselage directly into the motor.

Davegee

[Elbee]

ALonelyCorsair,

Welcome to Hobby Squawk, Sir. Glad to have you onboard.

Best, LB

[nuts-n-volts]

The Blue Diamonds version is as close as you can get either PNP or ARF. The decals are already applied but are easy enough to paint over if your going to redo it anyway.

[ALonelyCorsair]

Hello! I have a Corsair and am looking into one of these hornets. I want the customization option though, do you think there's anyway to get a Base Gray variant? Unless the decals come seperately

[Elbee]

Alpha10,, Beautiful Hornet, Sir. Nicely done. Best, LB

[Aros]

Niiiiiiice!

[Alpha10]

Such a great airframe...

I just finished my second custom 12s FW F-18 build... Came out awesome! :)

[davegee]

Maybe the fan adapter on the motor shaft is loose?

Also there may be a clear plastic piece where the ESC wires go forward that is moving?

Thanks for those suggestions, Evan. I am going to physically pull the motor out of the airplane today to inspect the fan area, just to be certain it is secure. This sound almost reminds me of when we were kids and would take a finger inside our cheeks and pull it out quickly, making a distinctive "pop." It only comes on when the throttle is advanced to the stop, and then only for half a second. Everything else seems to be in perfect working order.

I like your idea of maybe some plastic piece that is pulled in the suction of the airflow when it gets to max power. I'll look in those areas to see if I can come up with where this strange noise is coming from. I certainly have never heard it before in all the EDFs I've had over the years!

Take care,

davegee

[Evan D]

Maybe the fan adapter on the motor shaft is loose?

Also there may be a clear plastic piece where the ESC wires go forward that is moving?

[davegee]

Question on a small momentary "pop" sound when I do a static runup to full power. I took my new F-18C (with the old motor, ESC, wiring,etc) onboard out to the field to do a full power static runup, run taxi tests, range tests, etc. The wind was too strong a crosswind to hazard taking it up, so I got a lot done on the ground. It is very solid and seems to be ready for a new maiden (even though I got almost 30 flights on it before I "pancaked" it on a botched landing attempt about 6 months ago. That prompted me to just buy a F-18C ARF+and put the undamaged "guts" inside.

Everything was totally normal, except that I could hear a small, momentary "pop" sound when I ran the motor up each time to full power. It almost sounded like a little pop of air, and doesn't seem to come from anywhere back near the motor. Seems to come near the front of the fuselage, although I may be mistaken.

Holding the model by the vertical tail, it has gobs of power and I think the motor is very strong and healthy. But I still get that very momentary "pop" sound and then it goes away.

I'm wondering if anyone has ever had a similar occurrence with an EDF jet. I haven't. I'm still tempted to take it up for a quick flight around the patch later this week, for starters.

Appreciate any comments as to what this might be. Battery is solid and everything seems to be normal, otherwise. I've already pulled the motor cover and it looks to be normal.

Cheers

Davegee

[Elbee]

JeremySean,

Hugh Wiedman is "The Guru" among a bevy of guessers when it comes to these things.

Sage advice is what he does.

I think you have a good place from which to start your servo search.

Best, LB

[Hugh Wiedman]

Got a question. I’m looking to replace the aileron, flap and horizontal stab servos, what’s a good brand that won’t break the bank?? Also if you could list the servo model for each control surface that would be awesome considering their names can be confusing. Thank you guys!

I agree with Elbee. I have 2 F18's and both had issues with the stock FW 9gr flap servos and IMO it's absolutely imperative you at least upgrade those. In flight, one would usually not deflect, and it was almost never the same one (on the bench fine with no air resistance), making for a seriously squirrely (to say the least) flying aircraft when getting ready to land. The stock 9gr just didn't have enough guts in flight. Tried everything to correct it from reducing deployment speed from 4 sec to 2 to 0 (which was even worse when only 1 came down leaving it instantly rotating) and bypassing the control board and plugging them in direct. Finally accessed one of my few brain cells and replaced them in both F18's to the 11.9gr Hitec HS-5065MG+, essentially a drop in fit. Cost is around $38 each. Works like a dream now. As far as the others, I've never had a problem with the stock aileron or elevator servos so they both fly stock with those, not that it's a bad idea to replace those either, especially the elevator ones. Just check the dimensions on the Hitec site under Digital Micro/mini/wing all metal gear servos and pick your poison. I think the 21.9gr HS-5085 MG might work for the elevator/aileron, as I seem to remember those stock being the 17 gr servos but not positive.

[Elbee]

JeremySean,

I suggest either Futaba or HiTec for the servo brands.

Also, consider buying "all metal gear" servos from either brand for all your control surfaces where you change out servos.

As for size, there are just too many options; however, if you'll go to either website there are case sizes usually listed or diagramed for each servo.

You should be able to compare the OEM sizes to those listings if you have calipers.

That is what I do.

In any case the torque values for the 'metal gear' servos will be more than sufficient compared to the OEM servos.

Make note whether the OEM servo mounts are 'single hole' or 'double hole' per side.

Though it is not complicated, remaking servo mounts in the airframe can be a pain-in-the-butt if you are not familiar with that type of construction.

As you have probably figured reading the this forum, the elevator control surfaces could use a beefing up with stiffer hardware, and possibly the flaps and ailerons, as well.

Hope I've helped.

Best LB

[JeremySean]

Got a question. I’m looking to replace the aileron, flap and horizontal stab servos, what’s a good brand that won’t break the bank?? Also if you could list the servo model for each control surface that would be awesome considering their names can be confusing. Thank you guys!

[davegee]

I just received in the mail an ARF+ F-18C airframe from MRC. My previous Hornet I had for about 2 years until I “pancaked” it after it bounced high on landing and tried to save the landing. I Should have gone around for another landing attempt, but didn’t. The fuselage was substantially damaged and eventually I decided to get a new airframe and part out my old plane for spares, as needed. All the “guts” went into the new plane and I’ll be ready for a new maiden when the snow clears out from this latest snowstorm we got today.

The previous F-18 I had I put close to 30 flights before I fumbled the last landing. I am using most of the original settings in my radio as I had this plane pretty well dialed in.

My question is, I did put some Up elevator trim for deploying flaps. I took the measurements off my wrecked airplane and transferred them to the new model. Thing is, I couldn’t find anywhere that indicated I needed to add Up elevator when you deploy flaps. I have no idea where that info came from, although it seemed necessary to keep the plane in trim while using flaps.

Does anyone know where these figures came from, as well as other proven flight surface throw settings that work well for this airplane? Mine that worked well were at some variance with what the manufacturer recommends. I don’t really want to change what I have unless I’m sure they are better than what I used to use on my old airplane.

Thanks for any comments on this.

Davegee