Official Freewing 90mm F-4 Phantom II Thread

[locharrow]

Anyone running an FMS 90mm 12 blade in their F4? I like the 70mm ones I put in my SU 35 so might try one in the new F4 if anyone has good things to say about them !!

[GliderGuy]

Hi Locharrow, Glad she’s going again.
If you do experience a loss of control event in the future, the chokes might be a consideration for any follow-on bird with a high-current ESC.

-GG

[locharrow]

GG... just have a wee choke round the ESC - Rx lead.

I put a deep V cut along the crack in the wing, roughed it out and filled it with dry brown rice mixed with 1/2 hr epoxy, tamped mix into the V, let it dry, sanded, coat of fine filler paste,sanded again and primed. Works a treat....Didn't paint it as might re-do the whole plane. Flew it again this afternoon ...no problems at all. I'm beginning to think there was fairly stiff turbulent breeze above the trees in the park even although it appeared fairly calm at ground level.

[GliderGuy]

Nose gear was holding up OK...... till this afternoon! Fresh cut grass, no dogs or footballers so good to go. Got up, gear up, flaps up, gyro on...all the auto take off things done. I noticed the plane tipping on way then the other which in calm conditions ain't good. I then felt the plane slow to react to input so decided to do a circuit and come in but there was no way it was willing to do what it was told so I did a down wind dump while I had the chance. Bent nose gear pin, doors bust and cracked wing where the mains leg took the brunt of the dump. Fortunately all fixable but it makes powering up the new one more and more appealing !!!

Are you using RF Chokes? The time I had an A-10 and F-4 do this, I added chokes to the next/new replacements. Since I added chokes, no more loss of control issues.

Search on RF chokes or chokes and read the posts.

-GG

[locharrow]

Nose gear was holding up OK...... till this afternoon! Fresh cut grass, no dogs or footballers so good to go. Got up, gear up, flaps up, gyro on...all the auto take off things done. I noticed the plane tipping on way then the other which in calm conditions ain't good. I then felt the plane slow to react to input so decided to do a circuit and come in but there was no way it was willing to do what it was told so I did a down wind dump while I had the chance. Bent nose gear pin, doors bust and cracked wing where the mains leg took the brunt of the dump. Fortunately all fixable but it makes powering up the new one more and more appealing !!!

[locharrow]

All points taken but the superglue pad I put on the running bar switch tag has worked great and is still going strong. Time will tell. Went out today but dog "instructor" with sucker clients in tow screwed it up !!

[GliderGuy]

Good deal…my concerns are:
Lead is soft and may deform and allow the play to return. And, super glue easily fractures.

Might eventually need to use a different metal and a flexible adhesive like foam tac or Gorilla glue.

-GG

[locharrow]

Assuming the play is fore/aft play along the retract axis…you can disassemble the retract servo and remove the large silver rotating part. Then solder a thin washer to the side that hits the plastic body when in the gear down position. This thin washer will fill the gap and the play will be greatly reduced or eliminated. Use a washer that has the diameter of the width of the rotating body.

Reassemble the unit and check for proper operation.

-GG

The play was caused by a gap between the fulcrum and the running bar flat top. Not having a solder gun I tried hammering a strip of lead really thin and cut it roughly to the size of the running bar flat top and super glued it on. I trimmed it to the bar shape and did a few up and down tests. Had to trim it again as it sounded very painful but after another wee shave or two it worked great.

Have it installed and it's rock solid. !! The weather is still great so it's all good to go !

[locharrow]

"Get her something special, too."

She's got me !

[GliderGuy]

Locharrow, use a soldering gun vs iron. I was happily surprised how nicely the fulcrum wetted with solder. Use a washer type that also wets well.

Nice to have an understanding spouse! Get her something special, too.

-GG

[locharrow]

Thanks GG. I didn't think that fulcrum would solder but I'll give it a try. I had one unit where the travelling bar went too far and allowed the fulcrum to slip. I built up a superglue pad on the wee tag that hits the switch to stop it earlier and that. fixed it.

Shredded the nose of the SU35 yesterday in trees ...pure pilot error .. ..new fuselage needed....wife encouraged me to buy it

[GliderGuy]

Assuming the play is fore/aft play along the retract axis…you can disassemble the retract servo and remove the large silver rotating part. Then solder a thin washer to the side that hits the plastic body when in the gear down position. This thin washer will fill the gap and the play will be greatly reduced or eliminated. Use a washer that has the diameter of the width of the rotating body.

Reassemble the unit and check for proper operation.

-GG

[locharrow]

Out with the beast or/and the SU35 every day this week, some days two sessions. Unbelievable flying weather, very calm, light cloud with an odd light shower but not the blinding sunny days like last week. Fulcrum in the nose gear unit seems to have a fair bit of play after the pummelling of the hard pitted grass surface...any easy fixes or is it a new servoless retract unit ???
Temptation is getting the better of me, moved the new F4 from the spare room to the dining room table ...........

[Hugh Wiedman]

I'm thinking about retiring the beast as it has been up trees, landed in bushes and just plain crashed and fixed once.:

Those are the best kind, a warrior with experience still capable of going back into battle. Mine fly best the more epoxy they have and the more times it's been fixed after "mishaps". Trees are there for alternate runways. Just "fixed once" means it's virtually brand new! The aircraft I have problems flying are those that have never been repaired and are in "pristine" condition, they make me way too nervous. Fortunately, I have very few of those left in my hangar.

[locharrow]

Your further back than me Hugh, I came forward of 195mm because of the sensitive stab. I had a problem with wing rocking on nose high landing approaches but the gyro fixed that. I also removed a large section of the fan cover, framed it with 1/8th balsa strip and laid in a fine mesh grill to get air into the fan.

I'm thinking about retiring the beast as it has been up trees, landed in bushes and just plain crashed and fixed once. I have a new one in the spare bedroom that I look at and drool . Problems problems .................

[Hugh Wiedman]

Great flying weather, no wind, beautiful light blue/grey skies, most unusual over the past few days for Scotland, lovin' it ..plane behaving perfectly , easing back the C/G to "test the boundaries" and it's becoming twitchy on stab so I think I'll quit while I'm ahead !!

Where did you end up? On all my other EDF's, I'm usually at least 15mm or more behind recommended. For some reason, on the F-4, about 198 mm is my limit instead of the 190 recommended. She definitely doesn't like to get into too high of a nose up attitude at slower speeds without stalling, and seems some of that is from reduced airflow into the fan since it does not have any cheater holes. Not sure if that's correct or just my misconception.

[locharrow]

Great flying weather, no wind, beautiful light blue/grey skies, most unusual over the past few days for Scotland, lovin' it ..plane behaving perfectly , easing back the C/G to "test the boundaries" and it's becoming twitchy on stab so I think I'll quit while I'm ahead !!

[locharrow]

Very nice Hugh...the landing approach is very carrier style for an F4U . I puffed my LiHv 5200 Bolt battery so I'm back on HRB 6000s. Was back out this morning, great conditions.... but, after all my bumming about smooth landings, on my second flight I touched down wrong side of a ball ditch and had to hop ever it. Landed on the other side heavy-ish on the nose gear and bent the pin so that is afternoon gardening abandoned! All fixed now..had to clean the underside as it was covered in muck behind all three legs, water in the bucket was black, should improve the aerofoil considerably !!

[Hugh Wiedman]

What is the recommended blade count for the 8s setup? I started with the 6s 9-blade inrunner setup, but converted to the 8s 12-blade inrunner. Was wondering if changing the 12 to the 9 and keeping it 8s. Still sluggish on grass field take off.

I'm with locharrow , using the 6S 1835 Kv 12 blade, get's off in less than 100'. I believe the 12 blade has more 0-60 punch than the 9 blade, may not be as fast at top end (who knows though), but flying off of grass it's my personal "pilots choice" in fans. Have it in both my F-4's, the F-16 and both of my F-18 Hornets, all flying on an SMC 6200 mah 40C, although the F-16 also flies on the SMC 8100 mah giving over 5 minutes of flight time with no degradation in take-off distance or performance, IMO! Not the easiest fan on the wallet though, and at that price the least it should do is take you to dinner once in a while!

Have a friend at our field with the 8S 12 blade version and we both get off the grass in the same distance, although his is a bit faster (not a priority for me, take-off and unlimited vertical is all I need), and for some reason he just can't get over 3 minutes of flight time, while I'm at 4 minutes. Of course that all depends on the batteries and whether you're always at "firewall" throttle like he is!

[locharrow]

What is the recommended blade count for the 8s setup? I started with the 6s 9-blade inrunner setup, but converted to the 8s 12-blade inrunner. Was wondering if changing the 12 to the 9 and keeping it 8s. Still sluggish on grass field take off.

Fly off grass all the time .........Freewing 6s 1835kv 12 blade motor......not sluggish in the least. The F4 leaves the trap like a greyhound and is up in 30 yards. Might not break speed records in the air but does what it does with panache..........