million-air

You should always allow at least ten minutes in between flights if you have more than one lypo. This plane is fast enough that it receives plenty of incoming air especially when doing aerobatics such as loops. I havnt had a prob with it but I guess if it happens to you, well you know how to solve it. The esc is located right behind the fan on the upper portion of the fusalage two inches back. It is cleverly positioned so the esc stays cool at all times..like its own radiator. If you want the fastest, cheapest edf, get the F-35. It dominates and cost the same as the f-4. Out of my 1300 mah lypo..with good rationing of full throttle limited to low passes and loops...7-8 min give or take and gives you enough to circle the pattern again if you overshoot. I just received my 1800 mah lypo which should bump that to 10-11 min.

sanman55

good info...
Is the f-35 faster than the f-4? It has the same motor and is a little heavier than the f-4. I did see that one AFTER I had ordered the f-4. If I crash the f4 I will get that one,
Have anyone got that and what do they think?
Sounds like they did their homework on the f-4 for cooling, thats great.
Thanks for the good feedback
sanford

million-air

At least thats what the old man says in the video of the f-35. I heard its not that stable and you have to work your asstronaut off to keep it in the air. I like the f-4 look anyway and does well for me. Its nice showing up at the airport with a jet..dropping the battery and blowing the rest out of the sky speedwise. I know some people that think it would be cool to have six of em and fly in formation (blue angels obviously).

sanman55

Thanks, Thats what I hear too, hard to fly. I think I made the right choice..
[8D] get mine next thursday, will fly with landing gear on for first flight to get it trimed out. Don't like hand launch on maiden flights.
Will let all know how it goes in a week or so.........
watch that old man stuff, I am 61.......................

sanman55

cg- I found this great article on testing your cg. I think its worth looking at. Enjoy

Step 1: Basic trimming.
Fly like you usually do. Make sure you fly without any weird roll or yaw tendencies across a wide variety of throttle settings. In particular, make sure your motor thrust angle is not pulling you left or right at full throttle. Pitching up and down we will deal with after we fine-tune the CG, as long as it's not a huge, obvious problem. Like on my P-47, the moment I throttled up the nose would go down, even if I'd picked up no speed yet. That was a pretty obvious thrust-angle issue I had to correct before I could fine-tune my CG. If you require more than a couple of clicks of trim in any direction to stay in trim, land your bird and adjust the mechanical linkages themselves so that your plane is just about perfectly in "trim" without needing trim adjustments on the transmitter.

Step 2: Floating.
At about "three mistakes high", idle down to as slow as you can go without losing altitude and maintain level flight without a significant nose-up attitude. Do a few passes back and forth to make sure that you are trimmed perfectly to fly level, hands-off, at a very slow speed, just a few knots above stall speed if possible.

Step 3: Shallow dive test
From about "three mistakes high", going at the same flat, level, slow speed as in step 2, pitch your bird down about twenty degrees while maintaining throttle. This is a fairly shallow dive, but it should be steep enough that your bird is obviously picking up speed. Watch the nose.
If the nose pitches up (the dive flattens), you are nose-heavy.
If the nose pitches down (the dive steepens), you are tail-heavy.

I know this sounds counter-intuitive, but what you are doing with this test is increasing the air-flow over your horizontal stabilizer. If your plane is nose-heavy, your elevator will be trimmed with a significant amount of "up" to keep flat and level at low speed. Increasing speed makes the nose pitch up, since the elevator gains extra authority at higher speeds.

Repeat the shallow dive test until the plane tracks along the glide path perfectly. Some people prefer a slight bit of nose-heaviness; if you are in that camp, then trim it so that rather than tracking straight in, it slowly pulls out of the dive over 2-5 seconds.

Once you have this done, if you have a flat-bottom airfoil you may actually be slightly tail-heavy. Aerodynamics at work It's your choice to adjust it where you want it from here, but you know you're in the right ballpark for good flight performance.

Now that we have straight and level slow-flight characteristics, and no tendency to pitch into or out of a shallow dive at low speed, let's adjust the thrust angle.

Step 4: Thrust angle and lateral CG.
You should have made sure your plane was balanced laterally on the bench. Balancing on the spinner and the tip of the rudder with the tips of your fingers, it should have no tendency to tip either way more than the other. Aerobatic aircraft will tend to tip out of this test, but as long as one side isn't favored more than the other, you're fine.
At the field, put your plane into a steep climb, preferably 45 degrees. If your plane doesn't have the power to hold this for a few seconds, you may need to enter the climb from a dive. Do this 45 degree climb repeatedly (at least 5-10 times), with enough power to fall out of the climb after 2-5 seconds. Does the plane tend to fall out in a particular direction each time?
If it tips on the right wing consistently, either you are not laterally balanced or you have too much right thrust on your motor. Use washers or some sort of shim to correct the thrust angle to the left.
If it tips to the left, do the same but angle the motor right.
If it falls on the nose consistently from 45 degrees, you probably have too much down-thrust on your motor. Use a shim or washer to trim it upwards.
If the steepness of the climb increases on its own until the plane falls out towards the canopy, you are either tail-heavy or have too much up-thrust on your motor. Adjust your CG or use shims to add more down-thrust.

million-air

Nice...but really though, one or two clicks of elevator will solve any cg problems if stock. I mean its that small. Its so small that after five or six rolls you lose orientation and your forced to lightly input elevator to see if your up or down

sanman55

The phantom seems to be the exception to cg problems and thats great to hear. As I have stated I have the starmax gripen and its cg is WAY off , like one inch. So thats why I was concerned about it. I have gotten a lot of china made planes and they all have had the cg off.
That article is good for all planes ,not just the phantom. I play around a lot with cg to get the performance I need so I guess it matters more to me than most. In these small planes, and edf at that, weight and cg really affect the planes performance. I jus want the best performance I can get.
But I guess that might be getting too detailed. If you fly around with a lot of up elevator that should tell you that the nose is heavy, simple.
Flying inverted always told me how the cg was... just another tool.
Can't wait till I get mine and buzz around,
How does it do in stalls?
Have you done an amp draw and thrust check ?
I will find all this out but I am bored waiting .
sanford

million-air

CMpro is the worst. CG are wayyyy off in their manuals but good planes and relativaly cheap for good quality. The phantom here is not a good slow flyer...it just does not like it. On the other hand, it does not know the difference between up-right or inverted.

Ayrton

sanman55

Just flew the f-4 and its all it was said to be.........I LOVE IT... I did not even have to add any trim........
I am going to put my tp 2100 bat. in it next... It will make it a little nose heavy but I think ok. The cg was right on at 85 mm.
Plenty of power and not as bad to see as I thought. I love the acess hatch to the fan, nice touch.
I got 5 min. so with the other battery I ought to get 8 or so. Its hard not to get on it cause it is so cool. Everyone at the field was impressed. I think I will leave the landing gear on for now. I only got 2 flights cause it rained.........
Tested the stall and it just wagged a little, did not fall off or anything bad.
Pulling arount 280 watts at about 26 amps........ Mine weighed in at 17 7/8 ounces with the stock battery.
I am very happy.............Sanford

million-air

crashed it today. Snaps wayyyy to easily. I could do nothing about it. The damn thing looks like a puzzle now. Besides the plane is to small and gets anoying to fly.

sanman55

yep, its just too hard to see and you have to fly fast to keep it responding. Crashed mine a bunch.... I find I fly too far and will go in a stall and I can not tell what to do....
I made a take off dolly cause i took off my wheels and not much luck hand launching.....
Ordered the phase 3 ef-16 from hobby people. Its only $ 99 and includes motor and speed control....... bigger, flys slow and looks kind of fast.....we will see.. live and learn

million-air

personally I think these edf's are a rip of. The electronics were poor quality and the trim barelly works. Now this is no excuse for my crash but you get what you pay for. The f-4 is to fast and to small to enjoy flying because I had to work my but off to keep it in the air and everyone said to bring it back to 2/3 power for some reasons. It took off great from paved runway. It was fun and a little twichy but nothing I could not get used to. Then the plane snapped and since it has barely any wings there was no way I could gain enough airspeed to save it. The plane WILL NOT FLY SLOW. After the crash I did not have the since to put it back together because its ugly. I should of gone with the f-18. Its bigger and excellent from what I hear. Look at the videos, you will only find 2 videos of the f-4 which one of them is from factory and the other nitroplanes. Guy gave a crappy review if you ask me.

I feel better though. I just bought a sukhoi su-31 .40 from phoenix models. for a $130 arf with great reviews, looks, and performance why not? Going to put a Magnum .70 so that should give me some bang for my buck. Look for it at towerhobby.