Official Freewing 90mm F-4 Phantom II Thread

[BenAtkinsonUK]

"I thought about doing the same and in reality it’s the best option (realistically something I may even do in the future)...but for me it turned £150 damage into essentially spending nearly a grand on the thing in total."

Where are you buying your parts Ben. I bought my F4 kit from Flit Models and the fan from Along RC through Ali Express....seemed way cheaper than other suppliers, very good to deal with, great communication and fully tracked delivery.

Ah direct from motion RC - for the spares. (I was very approx with my pricing then!)...

Spending time on saturday going through the rebuild (not the weathering or cosmetic stuff yet .....what a waste of time that was first time around!) ha...

Thanks for the heads up tho - only thought Motion did their stuff

[locharrow]

Went out for a flight this evening, pretty late but tempting conditions.dead calm and light grey sky..I run the 6s Freewing 12 blade 1835Kv motor and since I timed it to 16% it packs a punch.Nearly paid the price tonight..... about ten yards into the take off run the noseleg hit a bump and the plane went close to vertical, :cold_sweat: very nearly hovering. It was more by luck than judgement that I managed to save it .....very scary but very pleased at the way the F4 responded to the controls in the situation. The flight itself was good, was able to do some fine trim adjustments after the sweat dried off..

[GliderGuy]

locharrow / Good job making the save! I've gotten into a couple of "Saber Dance" situations myself (typically resulting from a high bounce from a poor landing attempt). Forget about trying to save the landing. About the only thing you can do is go to full throttle as rapidly as possible and try not to over control as the F-4 dances about with the nose high. The fact that the F-4 typically just wallows instead of stalling and dropping the nose or a wing is its saving grace in these situations.
-GG

[Johnnyrabuse]

Good news just the other day I posted about my run in with the helicopter you know the real helicopter that buzzed my flying field at under two hundred feet

While my f 4 was at two hundred feet .....

Which caused me to cut throttle and stall it into the weeds

Well ....

After that crash I put the nose in hot boiling water broke out the glue and tried my best to fix it

But it didn't look good so I ordered a new airframe and yesterday it came along with a T 33 I don't have room for but I'll make it

Both are personnel favorites yes even more than my hornet f14 F22 f16 t 45 f15 l39 mig 21 f5 f 86 bae hawk f 35 not counting my prop planes which get no love at all because I'm insanely addicted to jets I'm sure I'm forgetting a few ohhh yeah my f 104

So I opened the box pulled out the nose cone and canopy stuck them suckers on and ....

It looks ok lmao now I have a brand new kit in a box so .....

I'm pulling the six system out of the fixed plane installing an 8 system and then flying the pants off it till the paint falls up I might even try tens

Then once I'm done ..... Putting it all in the new kit

Or maybe just hanging the new kit in the den next tmy framed f4 charcoal drawing ....

Gotta have an f 4 ....

Maidening the repaired f4 and new t 33 tommorow

Ordering the eight cell system tommorow night if it works out

Btw mig 29 is a sure thing next month my wife's going to kill me but you only live once ....

[locharrow]

:raised_hand:I have a question .......I know NOTHING about amps volts and watts...had guys tell me it was like water flowing from a reservoir ...pipe dia, ..pressure ..resistance etc., none works ...so. Until now I've been running 3 minute flights ,take off to touchdown,on 5000 batteries, when I check them after flying they show 3.89- 3.81or so but not below 3.80 ... To my simple mind,4.20 ,down to 3.80 in 3 minutes, works out that another 3 minutes would take the cells down from 3.80 to 3.40. I run down batteries in some planes much further but the discussions in this thread have put the fear of death in me about losing power at the crucial moment!! My question..... is the 3.80 to 3.20 going to drain the battery cells faster or at the same speed as 4.20 to 3.80? Naturally with similar throttle usage. I know I could experiment with longer flights but some of you will know!!

[Evan D]

The discharge of a LiPo is not linear and falls off rapidly after about 3.6-3.65V. It's also not good on the battery to take them that low. I aim for no lower than 3.8 which is what I use for storage voltage. If I am below that I charge them to 3.8 to store. If I do discharge down to 3.7 (or below) in a flight I'll quickly charge up to the 3.8 at the field. DOing this has given me good life from the LiPos I have.

[GliderGuy]

Agreeing with E.D. LiPos are typically good for around 300 full (3.2V min) discharge/recharge cycles. Not taking them below 3.8V can double this...or more. There is also a camp that stops the charge at 4.1V to further extend the life cycle count. Also, taking the battery to lower voltage means it takes more time to charge = fewer flights at the field.

Personally, I don’t charge at more than a 1.5 x C charge rate, and I stop flying at a cell voltage of 3.8V minimum. I have gotten 700+ cycles...more than double the typical life.

Lastly, for safety considerations, you need a reserve for a go-around in case things go wrong on approach or someone gets in your way on landing.

Examples:
F-4 = 3.5 min at 1/2 throttle cruising and some full power acrobatics and speed passes on a 6000 mAh pack
AL37 = 4 min on a 6000 mAh pack at less than 1/2 throttle cruising and some full power acro and speed passes
P-38 = 5 min on a twin pack of 3000 mAh 3/4 throttle and lots of acro and speed passes

Using a 5000 mAh pack for the jets? Shorten the above by about 30 seconds.

-GG

[locharrow]

Thanks guys, I take it from that info that I should stick at round about the 3.5 min max to be on the safe side and to preserve the batteries. I can comfortably get four minutes with my Freewing SU35 but that is with a lot of low throttle work. Back out tonight, great weather, light overcast and zero wind. Don't get that often in Scotland!!

[GliderGuy]

Thanks guys, I take it from that info that I should stick at round about the 3.5 min max to be on the safe side and to preserve the batteries. I can comfortably get four minutes with my Freewing SU35 but that is with a lot of low throttle work. Back out tonight, great weather, light overcast and zero wind. Don't get that often in Scotland!!

Scotland = pretty country. I'll pass along another couple of suggestions I have read and which I have incorporated into my battery care regimen. 1) Don't charge where the air temperature is less than 50 degrees F and pre-warm the battery prior to flying if less than 50 degrees F. This will help keep the cell's cathode material from developing cracks. 2) If the battery is hotter than warm bath water after a flight, consider buying a battery with a higher C rating. Heat is also a battery killer.

-GG

[Evan D]

All good info. I seldom discuss flight times compared to battery size because of different flying styles and that some use a timer that stops when the throttle is low and then resumes when throttle is given.

[locharrow]

"If the battery is hotter than warm bath water after a flight, consider buying a battery with a higher C rating."

I use Optimax and H/Duty Turnigy all 60 C and balance charge them at 2a. in an old microwave oven drilled to take the lead. The only bad experience I've had with lipos was when I carried a pair of 3s guys in my jacket pocket (old T plugs) and for whatever reason one started to fire up! Ruined a very nice jacket !!

[Evan D]

Using 2A for all charging could be a problem. You should charge at a specific C rating. If all your batteries are 2200's then you are okay but I assume you have some smaller and some larger batteries.

[Hugh Wiedman]

I lost an A-10 and an F-4 from what appeared to act like a brown out. Then I discussed with a HAM radio guy. Since my P-38 never has had radio issues and two EDF jets did, he suggested the common mode RF interference from the ESC is the issue. This can cause the transmitter and receiver to lose handshake/binding and give what appears to be a brown out. I installed ferrite RF chokes on the input side and output side of a new F-4's ESC and mounted them as close to the ESC as possible. Results...after a huge number of flights with the RF chokes, I have never experienced this loss of control again. Use the largest ferrite choke you can fit on each wire separately is best but a single large choke with several wires running through it works too. Any filtering is better than no filtering.

Reposting the below from a prior post a few months ago....

Add some clip-on RF chokes to each of the power leads going to and coming from the ESC. These high-current ESCs can generate common mode radio interference which might interfere with the hand-shake between the transmitter and receiver. Any length of wire between the ESC and the RF choke is an RF radiator. So, keep the chokes as close to the ESC as possible. I lost two EDF jets due to a transmitter/receiver hand-shake loss. Since I've added the RF chokes to the bird #2, I've had ZERO radio issues with bird #2 and have flown bird #2 hundreds of times for over a year. Get the clip-on RF chokes from Amazon.

• From Amazon.... Cedmon 20 Pieces Clip-on Ferrite Ring Core RFI EMI Noise Suppressor Cable Clip for 3mm/ 5mm/ 7mm/ 9mm/ 13mm Diameter Cable, Black

Use these, and say goodbye to radio problems when flying EDF jets.

-GG

OK GliderGuy I finally got the RF chokes you posted about after BenAtkinsonUK lost his F-4 on a set-up and programming I had recommended to him:face_with_symbols_o, which of course I have the exact same receiver, positioning, AS3X programming and sent him my .spm TX files on the 2 that I have, so hopefully most guys will learn not to take my advice on anything! :triumph: I put the chokes and also a remote satellite carbon fiber receiver in both F-4's and am fitting them in others as well (so far found the 7mm & 13mm most useful). Although I have yet to have a signal loss on anything except one jet that I stupidly ran the active antennae RIGHT ALONG SIDE OF THE BATERRY (can you say clue-less) , but after Ben's experience and your post, I felt it was better to be over cautious. Heaven knows I don't need a signal loss to bring one of my birds down, I do that quite well on my own.

[GliderGuy]

Hi Hugh...Looks good, Be sure EVERY wire going forward has a small choke on it or at least a green ferrite ring on it. Place the added chokes as close to the ESC as possible. See red circles in the photos for the wires I am talking about. Note: I am not showing the position for the chokes, but just pointing out all the wires that probably benefit by having a choke. Most especially important is the wire that connects to the receiver/throttle port. No need to move the position of the green ferrite ring. It's fine where they put it, I reckon. I didn't move its position on my bird's installation. Small chokes on the small wires is sufficient. You've got the big wires done right!

I did not put any RF chokes on the motor side of the ESC (3 blue wires to motor), and I have not had any issues. If you have room, putting a choke on the 3 blue wires placed near the ESC would make your system even more bullet proof...but it may be overkill and not necessary. Like I say, I didn't put a choke on the blue wires.

Bottom line...do what you can and what you have room for.

-GG

[GliderGuy]

"If the battery is hotter than warm bath water after a flight, consider buying a battery with a higher C rating."

I use Optimax and H/Duty Turnigy all 60 C and balance charge them at 2a. in an old microwave oven drilled to take the lead. The only bad experience I've had with lipos was when I carried a pair of 3s guys in my jacket pocket (old T plugs) and for whatever reason one started to fire up! Ruined a very nice jacket !!

As E.D. points out, these last few posts on batteries are general information....not hard and fast rules. There are several well written and detailed articles on the love and care of LiPo batteries for RC planes. If you use the proper C rating for your load (not getting a hot battery after flights) and don't pull them down below approx. 3.8 volts and don't charge them at too fast of a rate (1C is the mfg's recommendation) and store them at about 3.8 volts and carefully use them when it is cold outside....you'll have good results in terms of cycle time life. All good goals to keep in mind.

-GG

[BenAtkinsonUK]

Hey guys!!

SO....positive update...I've got the bird back together - looking good so far.

Now...electrics....bit of a rats nest but I've done my best to keep it neat and away from the RX antenna.

I've installed ferrite clips/rings - everywhere...haha. Both sides of ESC, right up against the esc - and on throttle cable. As described above. I've installed the RX away from the ESC - but it is under the battery tray, however the main antenna is in a similar place to where I mounted last time (RX was behind the main board). I found under the battery was easier to get to (and I have changed the orientation in the app, so the AS3X corrections are made in the right way). Extra cables from the RC Geeks Multi burner.

I'm gonna range test it in all orientations before I fly. I have also fitted a satellite Rx too for extra insurance.

The antenna are all at different angles so should be good.

Any feedback welcome....
Whats everyones CG measuring?

Again - thanks to everyone so far for your help its been brilliant.

Things are moveable to an extent though I have taped (with gorilla tape!) the rx in place. Most other bits moveable (so would the rx, but just be a pain)

Thanks - ben

[BenAtkinsonUK]

Oh and it would be rude not to show you this!

[Hugh Wiedman]

Oh and it would be rude not to show you this!

Nice Rebound, now go out and show us how it's done. GliderGuy I did get the wires you circled in red "choked" down in my photo that you circled (thanks again), that's why the choke on the black lead is larger, it also includes the throttle RX wire. As far as CG BenAtkinsonUK and at the risk of giving you more erroneous information on top of my previous batch of "winners", I moved my CG back from the book value about 4 mm to 5 mm. If I remember correctly, the book CG is 190 mm, so I found, for me anyway, I liked the way it flew at 194 mm.

[themudduck]

Oh and it would be rude not to show you this!

That looks like it came back together nicely, it looks excellent. Please let us know how your next flight goes.

I have been interested in this discussion and I have to tell you that I don't have ferrites installed in any of my EDF models (or any of my MRC planes for that matter) but I have satellite receivers in all of them (in my biggest ones I have two satellites). Ben I saw in your last post that you said "I have also fitted a satellite Rx too for extra insurance." When I saw that I said to myself, "there you go". So being clever as I am, I deduced that you didn't have a satellite RX installed originally. :face_with_raised_ey

Guys I am NOT saying that the ferrites aren't needed - but I think that its really important to have the satellite because its possible for a single receiver to be blanked out at certain orientations, for example if the signal is blocked by the battery or wires or whatnot. So all I wanted to say is: I recommend that everyone should use a satellite RX on their planes. (And I will get some ferrites for mine, for extra insurance.) The receivers that don't have satellites are for park flyers.

Regarding CG I'll just say that Freewing's pretty consistent in recommending really nose-heavy CGs and this results in planes that fly really straight and planes that like to destroy nose gears. So what Hugh said: move it back. I didn't even measure mine, I just moved the battery back and my Phantom phlies great. Recently I installed an Eagle A3-L gyro (from motion) in my Rhino and I am extremely happy with that. Yeeeha. :cowboy: (note: Motion is out of stock now)

[Elbee]

Oh and it would be rude not to show you this!

BA, Congrats, she looks great! It takes both a humble and determined man to get back on that horse that threw you. Very well done, Sir. Best, LB