Official Freewing 90mm F-4 Phantom II Thread

[Evan D]

I would have to search for specifics for my set up. I do remember the criticality of changing the elevator push rod (on mine the ball link started to deform) and ensure the elevator servo mounting is solid (it has stayed solid on mine in stock set up).

[locharrow]

Sad story.......great session on Sunday afternoon with the F4...so good I went home and recharged a couple of batteries and went out again. Up and away again I had a couple of minutes airborne and put the flaps and gear down and did the downwind leg and turned in. Thinking I was a bit on the high side I decided to go round again. This time when I went to turn in to the left land the plane just kept going. It then banked right and nose down disappeared behind trees. Couldn't find it at all, searched till dark then went home to drown my sorrows in single malt.

P##sed rain all night . Went out Monday to try again, asking permission to search fields etc. Gave up and went back to thank one guy who was particularly helpful and lo and behold saw just the tail of the plane sticking out of a ditch nowhere near I thought it was. Lot of nose damage and a crushed battery but all electrics, wings and tail are OK . New Fuselage and nose cone and she will rise again !! Despite the condition of the battery I got readings of 3.75 on all six cells ..a bit lower than the usual 3.8 odd but, I would have thought, not enough to blame the battery for the crash.

[GliderGuy]

Locharrow - That sucks. I am sorry that happened! Did you have the add-on ferrite RF chokes installed that were discussed in this forum several posts ago?

-GG

[locharrow]

Only on the Esc bec lead...

[GliderGuy]

Only on the Esc bec lead...

Look at the last 2 bullets of post #3974 for more info. I had an F-4 go down without these chokes. No issues at all since I installed them. Couldn’t hurt, for sure....cheap, easy to install, light weight.

You can group wires through a choke. I used 3 chokes as I added another to the wire with the green ring. Consider adding this filtering to ALL the wires in the image.



-GG

[themudduck]

One thing hobbySquawk could really use is stickied posts. I searched around a bit, but if someone would indulge me:

For the 8s version (I'm using 2x4000 HRB 4s packs), has the experience been to follow the throws, default elevator position, flaps-ele mix settings, and CG noted in the manual? Going to maiden and wanted to hear your experience. Is it the typical 'shift back the CG from what MRC recommends'?

I agree, stickied posts would be helpful. You can use the search function to find stuff sometimes.

Whether its 6S or 8S, all of the aerodynamics stay the same!

The plane is significantly nose-heavy using the recommended CG and a bunch of up-elevator trim is needed. Its also difficult to keep the nose up for landing. Once you get used to flying it, start scooting the battery back 5mm at a time (until you like it) and you'll definitely need less elevator trim and it will be much easier to land. Pay close attention to the elevator servo/control rod modification that's been discussed (what EvanD said)

[Waconut]

I flew my F-4 again yesterday with much calmer winds. I still had my hands full. The CG is just too far aft on my plane. I had added 3/4 oz of lead into the base of the nose cone and shifted the battery all the way forward. I thought I had it balanced at 205mm and rechecked this morning and it is closer to 208mm.
I moved the battery aft and added more weight to the nose cone. I am now balanced at 200mm with the ability to move the battery fore and aft to adjust the CG.
All I need now is some decent flying weather to try again but the forecast for the next 10 days does not look good.
The plane does look great doing low passes down the runway with the lightburner all lit up 🔥.

[themudduck]

I flew my F-4 again yesterday with much calmer winds. I still had my hands full. The CG is just too far aft on my plane. I had added 3/4 oz of lead into the base of the nose cone and shifted the battery all the way forward. I thought I had it balanced at 205mm and rechecked this morning and it is closer to 208mm.
I moved the battery aft and added more weight to the nose cone. I am now balanced at 200mm with the ability to move the battery fore and aft to adjust the CG.
All I need now is some decent flying weather to try again but the forecast for the next 10 days does not look good.
The plane does look great doing low passes down the runway with the lightburner all lit up 🔥.

When I started with this plane is was set up nose-heavy.
I'm using a RT6250 and the front of the batt is about 2.25" back from the front edge of the plywood tray - so its set back. I checked and my F4 is balancing right around 200mm. I think it flies really well at that CG. So that should be good for you...
I did not add any weight (I have a burner). It seems strange that you've had to add a bunch of weight in the nose. My RT is 796gms. What does your battery weigh?

[Waconut]

My battery is 735gms. Not sure why I am needing so much nose weight. I did give the plane 2 paint jobs, was not happy with the shade of gray on the first. But that shouldn’t made much difference.
I have added 2 ounces of weight up front. At least now I have some adjustability for the balance with the battery position. I can tell you she is a handful if you get the CG too far back. Does not want to turn and no lateral stability.

[paulsnapp]

Look at the last 2 bullets of post #3974 for more info. I had an F-4 go down without these chokes. No issues at all since I installed them. Couldn’t hurt, for sure....cheap, easy to install, light weight.

You can group wires through a choke. I used 3 chokes as I added another to the wire with the green ring. Consider adding this filtering to ALL the wires in the image.



-GG

In the photo only the wires coming from the ESC are circled. Are you saying to put a choke on all wires coming from the ESC and no need to put chokes on the 3 wires going to the motor?

[GliderGuy]

In the photo only the wires coming from the ESC are circled. Are you saying to put a choke on all wires coming from the ESC and no need to put chokes on the 3 wires going to the motor?

That is correct.

-GG

[e4dragongunner]

Starting on my 3rd Rhino! 8S ....

[Elbee]

Starting on my 3rd Rhino! 8S ....

E4, Looking forward to watching your build. Best, LB

[e4dragongunner]

Thanks Elbee.

I redid my entire shop to make finishing projects more streamlined. Hope to have a regular cadence of progress. Will be modding the nose gear with a case hardened steel pin, and modding the elevator servo mechanics utilizing a JR digital servo.

[nuts-n-volts]

Nice shop! Good luck with the new one!

[e4dragongunner]

Digging in ....

[Tonybons]

Hi everyone. I’ve not posted for a while so I thought I’d post an update but want to first thank all of you that we’re so helpful to me in the early days of my 8S F4. I really love it in all respects - look, flying capabilities and the absolute ease of taking it to the field unloading and reloading compared to all my other aircraft.

First of all my Phantom still lives. I have 60 flights on it and I have finally mastered it after some tough early days. Took me about 20 flights and a replacement fuse and 2 replacement nose gears to get the balance correct and land it very well consistently. As some know, I fly a variety of turbines as well as large scale aerobatic and warbird gassers. This plane was harder to land then those. I’m sure it’s been mentioned here a million times before that you have to land with power and the balance is critical. I actually added an idle to mine as I really don’t like throttling down and have no power at low stick.

Here are some points on my Phantom that work for me. Some might disagree and I respect that as flying styles and throws are personal:

-I did follow the numerous suggestions re the stock elevator set up and installed a Hitec 5345 with a 4-40 turnbuckle push rod and 4-40 ball links - all excluding the servo that I use in my jets and large scale planes - pic below.

-I am not using a gyro.

-My CG is at the suggested CG of 190mm. I originally used an EZ balancer that was inaccurate and inadvertently flew the first 10 flights with a CG of around 210mm which was far too tail heavy. Fortunately my F4 survived these tough landings. Once I rebalanced and achieved the recommended 190mm CG everything smoothed out and the plane flew great

-In the beginning, I used the recommended throws on all surfaces except the elevator where I used my own lower throws as I felt the recommended throws were too much. I eventually changed the elevator throws back to the recommended throws and they are definitely better.

-I found the admiral 4s 5000 mah batteries below expectations and I’m now using 2 4s 6000 mah packs that I bought from Amazon (2 for $95) that give me about 4 minute flight times that I’m still slowly increasing.

-I ordered the grey scheme as I wanted a specific custom scheme. I ordered the custom graphics from Callie which were reasonably priced and arrived on time in line with her originally stated timeframe. I told her she could offer it as an option if she wanted to. Pic of plane below.

-Lastly, treat the plastic clevises and other free wing hardware with care as they are very fragile especially the plastic pin that goes into the hole in metal steering part of the nose gear. I had to replace that clevis a couple of times and it’s not easy until you do it enough times to develop a system to make it easier. I now have a masters degree in that 😂😂

Good luck with your Phantom. Feel free to post thoughts or questions. I’ll be more then happy to help as I was helped. Happy flying.

Tony B

[Tonybons]

1 more point I wanted to mention. On the 8S version, the heavy wires coming from the EDF and ESC also include a switch and a UBEC. I originally velcroed the switch and UBEC to the side wall of the fuse. I didn’t realize and thank God I caught this on the ground, both wires that are soldered to the EC5 connector and go to the UBEC broke at the point where they attach to the UBEC from the constant pulling apart of the battery from the EDF/ESC. I solved this by simply velcoing the UBEC and switch to the EDF/ESC wire.

Tony B

[e4dragongunner]

Great report
And agreed. This is an advanced platform for certain. Especially to get everything set up correctly.

I am on my 3rd F4. Crashed the 1st. Lost orientation ( flying with out the tanks) Oops! My Second had many flights and I recently sold it to a good friend.

Love your data on the 6000's for 8S. I too will be going this route.

My question is on the EZ balancer.....
You wrote...

"My CG is at the suggested CG of 190mm. I originally used an EZ balancer that was inaccurate and inadvertently flew the first 10 flights with a CG of around 210mm which was far too tail heavy. Fortunately my F4 survived these tough landings. Once I rebalanced and achieved the recommended 190mm CG everything smoothed out and the plane flew great "


How is the EZ balancer inaccurate? I CG'd my 1st two Rhinos at 195 mm with out issue.

Thanks again.

[Elbee]

Digging in ....

E4, And so it begins.... Best, LB