Great to hear Matt! I am excited to see your pics, I am really stuck on where I want to mount the esc?? I am right behind you thou I have retracts done with steering and retract servos mounted, just stumped on a way to get the esc some good airflow! I am estimating 7.5 lbs with batteries as well so totally excited to see your maiden!

Brian

I mounted mine inside the exhaust tube right before it splits. Did same with Mig 15. The escs never get hot in the thrust tube. If they do there is something wrong.

You dont lose but a 1%-2% in eflux velocity and you never have to worry about how to cool the esc : )

Will take a few pics tonight for you.

Matt

Originally Posted by bri6672

Great to hear Matt! I am excited to see your pics, I am really stuck on where I want to mount the esc?? I am right behind you thou I have retracts done with steering and retract servos mounted, just stumped on a way to get the esc some good airflow! I am estimating 7.5 lbs with batteries as well so totally excited to see your maiden!

Brian

Here are some pics. She is ready to go.

few more

Anybody else see a potential problem here?
The Mains are located much to close to the CG.

Take a look at the Full-Scale Super Hornet pic below. Note that the Mains do extend from close to the front of the Intake, but angle back... then the knuckle-gear angle back even more to place the actual tire (point of rotation) alot farther back.

Now take a look at the build pic.
Based on a few of F/A-18 models I've had the pleasure of flying, CG should be right around the red hash-marks... and that's being conservatively nose-heavy. The black line represents how close the Mains (rotation point) are in relation to the CG.

As the model rotates for T/O, you're going to run the risk of the CG moving aft of the Mains even at low AoA, and a wicked tail strike for sure.

Everybody else building this bird, check your Main Gear legs' placement in relation to your CG... based on this picture, it appears that they should be at least a good 2" (if not more further aft) on the airframe.

Definitely report how it goes on the maiden though!

I had an F-15 like this as well but it never seemed to have an issue, as long as you are light on the elevator you should be good, plus there are some video's out there with it flying with the mains at that location.

Who knows. Just an observation.
Or it could just be a *funny picture illusion*?

Maiden will tell all! lol

an option might be to use their struts which would move the mains slightly rearward...



http://www.x-flight.com.hk/index.php...&more=&lang=en

Yep, wouldnt be too worried either, usually its the other way round. Main gears too far back from CG and elevator just dont have bite to get airborne and if it does, it usually pretty aggressive take off that ends on stall.

F/A-18s with an all moving stabs have an incredible pitch authority. The gear opening is in the correct position IF you use a knuckle/knee type gear like the full scale. The other option is to bend the gear strut to match the side view of the full scale. The second option means that the opening is too big and needs to move forward. The third option is to just fly it as is.... carefully

Here is my positioning of my gear and the knuckle/knee done with toggle bolts.....old and proven reliable (Home Depot seal of approval)
https://www.rcgroups.com/forums/show...6&postcount=23

Couple of things I noticed that raised an eyebrow. I don't like using EZ connectors on the ailerons especially for jets. Too much chance for a slip. Much better off with metal clevis. Also, I don't see a Z bend for elevator pushrod at the servo? What’s to keep it from popping out of the servo arm? Are there covers for the servos in the wing?
Also, those are some huge cutouts made for the gear. In the future, you can cut out an oversized square area of the entire landing gear area , which allows you to get to all the gear during construction and future maintenance. Fine tune the cutout for the gear on the plate you just cutout, minimizing all gaps, then secure the final gear cover with small round head screws at each corner. This will give you a nice, neat and tidy installation with most of the landing gear covered by the plate.
Just a few suggestions,
Good luck with the maiden.

The specified CG is 1-1/4 from forward of the middle of the main tire as mounted. I think this is a good starting point. The retracts can be mounted up to 1 " further back if need. Nice touch. With one or two taxi tests it will be easy to tell. I would rather have them closer to the CG so I do not have to jerk it off the runway.

Originally Posted by AceMigKiller

Anybody else see a potential problem here?
The Mains are located much to close to the CG.

Take a look at the Full-Scale Super Hornet pic below. Note that the Mains do extend from close to the front of the Intake, but angle back... then the knuckle-gear angle back even more to place the actual tire (point of rotation) alot farther back.

Now take a look at the build pic.
Based on a few of F/A-18 models I've had the pleasure of flying, CG should be right around the red hash-marks... and that's being conservatively nose-heavy. The black line represents how close the Mains (rotation point) are in relation to the CG.

As the model rotates for T/O, you're going to run the risk of the CG moving aft of the Mains even at low AoA, and a wicked tail strike for sure.

Everybody else building this bird, check your Main Gear legs' placement in relation to your CG... based on this picture, it appears that they should be at least a good 2" (if not more further aft) on the airframe.

Definitely report how it goes on the maiden though!

The Z bends are on the elevator. Just hard to see them on the picture.

As for the the ailerons, have not had any problems in the past with them using properly sized quick connectors.

Yes the cutouts are a bit too large but I originally set the gear up too long. The larger cut outs did help me with some wire routing. I have the cut-outs and plan on making some gear doors in the future so if she flies well and last long enough this mistake will be taken care of.

Thanks for the suggestions.

Matt

Originally Posted by KHorton

Couple of things I noticed that raised an eyebrow. I don't like using EZ connectors on the ailerons especially for jets. Too much chance for a slip. Much better off with metal clevis. Also, I don't see a Z bend for elevator pushrod at the servo? What’s to keep it from popping out of the servo arm? Are there covers for the servos in the wing?
Also, those are some huge cutouts made for the gear. In the future, you can cut out an oversized square area of the entire landing gear area , which allows you to get to all the gear during construction and future maintenance. Fine tune the cutout for the gear on the plate you just cutout, minimizing all gaps, then secure the final gear cover with small round head screws at each corner. This will give you a nice, neat and tidy installation with most of the landing gear covered by the plate.
Just a few suggestions,
Good luck with the maiden.

I just read this thread from the beginning. Nice looking jet. I'm on the edge of my seat waiting for a flight report!

BRI6672 Jetscreamer make a 90mm motor, its called a 1400 motor just like the little 70mm one.