Karnsy

I was given an Airfield F/A 18 Blue Angel 64mm EDF RTF Jet
The issue is it is very under powered for flying off short grass and sometimes will not lift off. It calls for 3s 1800mah and I am using 3s 2200mah. What is the easiest or best thing I can do to get more power.
Thanks for any help you can give !


In jet right now is stock
- Motor: Brushless P2627-4100KV
- Battery: LI-PO 11.1V,1600mAh 20C/// I use 2200mah
- ESC: 30A Brushless ESC

birdDog

Probably going to end up using a hand launch or bungee launch system to get away from the small wheels in the grass problem. Larger wheels may help but will most likely still struggle to accumulate the needed speed.

fhhuber

They need more air intake cheater hole area. The fan is starving for intake air.
Double the cheater hole length and width on each side.

They changed some since I had one (incorporating most of the changes I made to mine, which I reported to the manufacturer) but they didn't open up the cheater holes. These are the slots in the belly to let more air get into the fan.

The 2200 mah may or may not be part of your issue because 3S 2200 mah 20C is max weight. Higher C rating is heavier. I ran mine on 3S 2200 mah 20C Sky Lipo of appx 4 to 5 years ago.

With the larger cheater hole... Takeoff run is appx 150 ft paved smooth surface. Throttle to appx 1/3 and then smoothly advance throttle to 2/3 over the takeoff run. Slapping it to full throttle from a standing start will actually reduce acceleration rate and make you require 300 ft or more using paved runway.

It can do grass but it takes more runway depending on the grass.

solentlife

Many EDF's stock spec'd on 3S are run on 4S by owners ... usually means just a change of ESC. A 30A ESC on a 64mm EDF is about the minimum you would want on 3S and would not survive a 4S ...

Many EDF's on grass are abysmal anyway ... due to inefficient fans ... and small wheels.

Nigel

dahawk

+1. 30 amp esc on 4S will be toast. I fly my edfs off grass. Short dry grass. The little wheels and if a lot weight over the nose wheel will make it a car. I know all too well.

Hawk

fhhuber

More voltage won't help if the fan is already unable to "breathe" correctly due to inadequate air inlet....

And that fan is suffocating until the plane is up to speed.

solentlife

Fair comment.

My post about 4S replacing 3S is a common swap on many edf's and was just adding to the list.

Nigel

Karnsy

Well, maybe I just settle for as is.
I was thinking maybe it would be worth just sliding a bigger esc and 4s in but not sure I want to spend the time or energy on rebuilding. Might just put my effort in a bigger faster model. I just kinda like the Blue Angel model. Thanks to all !

dahawk

I'm flying edf's from 50mm, 64mm, 70mm and 80mm. No 90mm's and above yet.

My current favorite is the Freewing Yak-130. Primo ! I have the 6S version but they offer a 4S version as well. Easy to fly, reasonably fast ( ~ 90mph), great on grass, STAL capable, easily upgradable to a 13bl XRP, high visibility. All the good and none of the bad. Only $200.00 shipped

Then there's the FW Northrup F-5 Tiger II. Wow ! a rocketship with a set of wings attached. What a hoot !

Karnsey, my FMS F-16 is very similar in size to your F/A 18 I fly it with 3S and 4S but it does come with a 50amp esc. I took the gear off and hand launch/belly land. If you like the way it fly's stick with that set-up and have a blast !

Hawk

fhhuber

Not much time needed to open the cheater holes... just a sharp knife.

http://site.hobbypartz.com/pimages/9...Blue-ARF-7.jpg

The holes in the belly , behind the scale air intakes and between the main wheels. Double their width and length. Being exact isn't as important as making those 2 holes bigger.

Originally these came with a 900 mah 3S 12C that went in front of the front wheel.

I found the front fuselage was hollow under the canopy and opened mine up. A 2200 mah 3S 20C dropped in and CG didn't change. Huge improvement in flight time and power vs the 12C 900 mah. The added weight made the plane need a lot of runway so I played with the cheater holes, slowly opening them up. No improvement going larger than 4X original area. (I had mine at 3X width and 2X length)
The larger holes don't help with top speed... but do help with getting up to speed for takeoff.

Karnsy

fhhuber,

Well I cut the holes in the belly , behind the scale air intakes and between the main wheels. I Doubled their width and length. I also raised the front wheel height a little thinking better air underneath, we'll see. I have not had a chance to test it yet but I figured by doing it I had nothing to lose. I will keep you posted

fhhuber

Not sure of the result from altering the wheel height...

What that typically does is force the plane off the ground earlier which may or may not cause a stall.