Official Freewing 90mm F-4 Phantom II Thread

[Alpha]

Hi Kevin,
Is the gear door's servo receiving power? Does it resist your finger if you try to gently push it out of its current position? Same question for the rudder.

[Kevin R]

No, no glory no power. Weird.

[Kevin R]

Btw....I love Motion RC products. I have the Tigercat, A4, MiG 21, and F4. All fly great. Every bit as nice as my turbine jets I had. Much prefer the low cost, high value to turbines.

I wish Freewing would do a 90mm F-8 Crusader.

[Alpha]

Did you try plugging in the nose door servo into a different slot that IS working? This will rule out the board or the servo itself. Same for rudder.

[Kevin R]

I’ll give that a shot.

[Kevin R]

[themudduck]

I love the paint scheme on the MiG-21, that's really sharp!

With your servos, I agree that in order to isolate this problem you should test the servo (like with a servo tester) - so that you can determine for sure that the servos are working. Then you work backwards to find the problem.

For example, the rudder on the F4 has an extension. So unplug the rudder from the extension and test the servo directly. If it works, then plug it back into the extension and see if it still works with the extension plugged into the tester. Work back towards the receiver and you should find what's causing the problem.

If you find the problem in the first step (the servo doesn't work) then it may simply have a broken wire inside the case, that's an easy fix or you can just save it for spare parts.

[MikeT]

While seeing up a friends F4 I ran across a bad extension. Took a few minutes to find it but that's was the issue.

Mike

[Kevin R]

I love the paint scheme on the MiG-21, that's really sharp!

With your servos, I agree that in order to isolate this problem you should test the servo (like with a servo tester) - so that you can determine for sure that the servos are working. Then you work backwards to find the problem.

For example, the rudder on the F4 has an extension. So unplug the rudder from the extension and test the servo directly. If it works, then plug it back into the extension and see if it still works with the extension plugged into the tester. Work back towards the receiver and you should find what's causing the problem.

If you find the problem in the first step (the servo doesn't work) then it may simply have a broken wire inside the case, that's an easy fix or you can just save it for spare parts.

Thank you you for the reply and complement on the MiG 21. It came out fantastic. The VPAF camouflaged few of their 21s, this scheme is my fav. I mixed a custom water based acrylic and sprayed it over the silver. Quite a bit of silver is evident under the light green. Then I used enamel RLM 80 Dunkelgrun flat for the darker color. It came out really nice.

[///INVERTED\\\]

Ghost Grey 8S version? Is it coming? What say you Alpha or James?

[Kevin R]

So it was a dead rudder servo and dead door servo. Two replacements are on the way.

[Kevin R]

Ghost Grey 8S version? Is it coming? What say you Alpha or James?

I asked Motion today, no plans on 8s 90mm grey naval version.

[themudduck]

So it was a dead rudder servo and dead door servo. Two replacements are on the way.

Yep, that happens from time to time. Save those puppies, lots of spare useful parts inside! If I were you, since you have nothing to lose... I would take the cover off the servo and check for a cold solder joint where the wire is attached to the circuit board. If the worker didn't do that correctly then you've got a perfectly good servo that isn't working simply because of one bad connection.

Good news that MRC replaced the servos for you. Top-notch customer service.

[Kevin R]

Good point. Funny thing is, I removed the cover and found the circuit board and solder points covered with what appears to be caulk-white caulk that they used to glue the servos in place! I cleaned them up, but havnt tested them. I’m reluctant to use them if I get them working. No sense in possibly losing a 700.00 model because of a 10 dollar servo!

[themudduck]

Good point. Funny thing is, I removed the cover and found the circuit board and solder points covered with what appears to be caulk-white caulk that they used to glue the servos in place! I cleaned them up, but havnt tested them. I’m reluctant to use them if I get them working. No sense in possibly losing a 700.00 model because of a 10 dollar servo!

I agree... It doesn't make sense to take a chance with such an inexpensive part. I just meant, you have nothing to lose by checking and sometimes you will find something that is really obvious and simple and "zoink" you can have a perfectly good servo. But otherwise, just keep it for spare parts. I have stripped gears on occasion and its great when you can just stick in a new gear set and keep on truckin'.

[andrew_flyguy]

Is the Navy gray version that is coming all gray on top including the vertical stab?

I'm wondering the same thing. Grey Ghosts sure looks like a painted tail to me, and I don't know how easily a Sundowners vertical stab would work out if it were just a decal over dark paint...

[Alpha]

I'll post an update on this question later this month once finalized, standby.

[Hugh Wiedman]

Just did a "hammer" test on the stock F4 nose pin that several guys have complained break instead of bending. Although I installed a modified Spitfire wheel axel in the nose pin when I initially built it, I have yet to bend or break this one. I was able to snag some extra F4 stock pins and Spitfire axels when they last became available (yes, I had to quickly order late at night when they came in and got the last few of each), but I thought the F4 pins I purchased looked exactly like the Spitfire wheel axels and not like the pictures posted of broken pins. I'm not one for intentionally destroying spare parts, but I was wondering if Freewing changed the pins as a result of all the complaints, and I just had to know for sure. I also was curious to see if the Spitfire axel would break or bend, considering all the trouble it takes to install that. Well, take a look at the photo. The F4 pin snapped right off on the 2nd rather minor hammer strike. The first strike bent it maybe 1mm, but the 2nd snapped it clean off. The Spitfire wheel axel could not be broken, and ended up bending 90 degrees. So for me, the jury is in. I got the feeling that the Spitfire axel was a "softer" metal and would bend before the stock F4 pin broke, however, I suspect that after several hard landings with the stock pin, the metal fatigues and eventually breaks anyway. At least with the axel, you can see when you've come in too hard on the nose and replace it.

I would much rather bend the pin than snapping it off as I suspect that in the process of a break, the gear doors, lights and bottom of the nose cone would also be damaged. I've bent the nose pin in my Stinger 90 before and it only required changing it out. I could even still fly at the field if it wasn't severely bent. Of course, with a hard landing you may also ruin the retract, but if I have to remove it for a broken or bent pin, might as well install a new one.

Just wish they made the pin removable with 2 set screws on either side of the trunnion, instead of having to remove everything, take the retract apart and then install the pin. Not the easiest thing to do at the field, heck, it's hard enough on the bench with those micro screws in the retract. Thankfully I have a full set of jewelry tools or it would be impossible.

If you do decide to replace the pin with the axel, and are lucky enough to get them when back in stock, the modification is to extend the flat spot on the axel to match the original and grind down the diameter of the back stop so it freely rotates. The wheel axel in the photo was before modification.

[fhhuber]

Music wire, Jeweler's diamond file and drill press. Cut the music wire to length, chuck it in the drill press and you can mill in a slot for an e-clip.

You can do it with any power drill that you can lock on and can secure in place to leave your hands free.

Music wire resists bending more than the OEM pin. It will bend before it breaks. When it bends, it might pop the e-clip and drop the gear, especially if the slot has a taper.
Dropping the gear can be good or bad. If it happens on take-off you are committed to a belly landing. But the damaged gear won't interfere with closing the gear door.

[PhantomNut]

This problem with the nose gear needs to be addressed by Freewing so nobody needs to worry about this happening to them. I'm on the fence of getting this model and I don't want something I'm going to need to modify out of the box.