Official Freewing 80mm MiG-21 Fishbed Thread

[southernmd_man]

Quick question...do both current versions of the MIG come with ribbon connectors for the wings? I hate dealing with spaghetti at the field before flying.

TIA!!

[paulrkytek]

Is there a mod to make the drop tanks removable? I assume I could just use magnets, but I would worry about loosing one under "G" and I bet that is not fun!

Just double the number of magnets, you are more likely to loose the drop tanks on landing than flying

[paulrkytek]

I just glued the rear fuselage on mine and have a bit of an issue. I used BSI foam-cure, but did not realize that it bubbles a bit as it cures. Given the large surface area being glued, it pushed the two parts apart as the glue cured. I have a gap of about 1.2mm at the top and .8mm at the bottom. It was out enough that it cause the holes for the rudder mount screws to be mis-aligned by about 1/8 th inch.

Did anybody else run into this before? Did it create trim issues?

I would normally just run with it , but I am doing a turbine conversion, so the stakes are higher. A new fuselage is $100 plus a couple days of work lost.

I am not worried about the strength of the joint, but the mis-alignment of the tail assembly creating a control problem.

Any thoughts?

Is the gap just top to bottom or top to bottom and a bit of left to right/right to left. Wider at the top means you are about 1mm down at the back of the thrust tube which is not a lot but might lead to a small amount of nose down thrust as you throttle on. If this is the case you may be able to correct with throttle to elevator trim mix so that the elevator trim goes up in proportion to the thrust if it becomes critical. Also a touch of normal elevator up trim might be required on maiden flight as wing to horizontal tail incidences may have changed a fraction also inducing a touch of down into the calculation affecting normal angle of attack/stance of the model in the air. Difficult to judge without setting the model up on the bench and taking offset measurements from parallel lines both side of the fuselage for left to right but again this could be trimmed out. When you consider that the Dynam ME262 had a thrust line way below the wings and I got that to work with some throttle/elevator trim ( around 10percent ) and resetting the horizontal tail incidence to a better position then I would have thought that the amount of difference in thrust line you have could be trimmed out. I do not know anything about turbines but if you are using a thrust tube liner perhaps you might look at fitting and re aligning a suitable thrust tube to bring the trust line back on course so to speak depending on the thrust tube dia calcs. Well, right or wrong those those are my thoughts and no doubt others will give you more. Good luck..

[Dave Wave]

I just glued the rear fuselage on mine and have a bit of an issue. I used BSI foam-cure, but did not realize that it bubbles a bit as it cures. Given the large surface area being glued, it pushed the two parts apart as the glue cured. I have a gap of about 1.2mm at the top and .8mm at the bottom. It was out enough that it cause the holes for the rudder mount screws to be mis-aligned by about 1/8 th inch.

Did anybody else run into this before? Did it create trim issues?

I would normally just run with it , but I am doing a turbine conversion, so the stakes are higher. A new fuselage is $100 plus a couple days of work lost.

I am not worried about the strength of the joint, but the mis-alignment of the tail assembly creating a control problem.

Any thoughts?

[radfordc]

Is there a mod to make the drop tanks removable? I assume I could just use magnets, but I would worry about loosing one under "G" and I bet that is not fun!

They are removeable and come with magnets. The only time I've had them come off was on a hard landing.

[Dave Wave]

I am always amazed by the flight envelope of this jet. It can fly as slow or slower than any Freewing jet I own, does bat turns, if it stalls I didn't even notice! Seriously, why stall it? You can bring it to a stop in high alpha and fly right out. It goes where it is pointed and does great 4 point rolls, KE, the works. Only fault IMHO is it is draggy and eats batteries pretty quick, it's no glider. Of course it is on the "hard to see" side, I use a gyro and think it helps to lock it in to any flight attitude. Oh, it is great in high winds and is truly great in a crosswind, it will land as slow as you dare, I would choose it for the shortest runways. Just looking at it it doesn't make sense, but there you are.

How is it without the gyro? I have thought about one, but that is just one more thing to go wrong....

[Dave Wave]

Is there a mod to make the drop tanks removable? I assume I could just use magnets, but I would worry about loosing one under "G" and I bet that is not fun!

[MeyerVW]

Its a fun aircraft. Flew it some more. FUN FUN.

[Husafreak]

I am always amazed by the flight envelope of this jet. It can fly as slow or slower than any Freewing jet I own, does bat turns, if it stalls I didn't even notice! Seriously, why stall it? You can bring it to a stop in high alpha and fly right out. It goes where it is pointed and does great 4 point rolls, KE, the works. Only fault IMHO is it is draggy and eats batteries pretty quick, it's no glider. Of course it is on the "hard to see" side, I use a gyro and think it helps to lock it in to any flight attitude. Oh, it is great in high winds and is truly great in a crosswind, it will land as slow as you dare, I would choose it for the shortest runways. Just looking at it it doesn't make sense, but there you are.

[Dave Wave]

Can anybody comment about the low speed handling of this model? What happens in an accelerated stall? Any bad traits in a normal power on/off stall?

[quitcherbitchen]

I like your North Vietnam and the Polish schemes. Nice job guys.

[pullupnow]

Don't be afraid to slow her down.. Not like when I almost hit the trees :} but you know what I mean

[MeyerVW]

Need more time with this bird. Not to bad but work is needed for better flying on my end.

[paulrkytek]

Here it is. Love the look I got and I am very happy so far. Waiting on a nose brace and fire booty. When flap are deployed is there any need for elevator trim?

I have not found elevator trim with flaps necessary on mine.

[MeyerVW]

Here it is. Love the look I got and I am very happy so far. Waiting on a nose brace and fire booty. When flap are deployed is there any need for elevator trim?

[MeyerVW]

I am trying to get the stock MLG wheels off. The grub screw looks like it has loctite on it and a 1.5 mm hex is a loose fit. I tried heating with a soldering iron, but no luck. Any tips/ tricks to getting the screw out?

I have found that SAE allens will fit better in some metric grub screws. And some metrics will fit better in SAE grub screws. I use both knowing the hardware is most likely metric. Also put the allen in the screw and give it a few taps with a hammer to loosen it up. Heat works too sometimes.

[Dave Wave]

I am trying to get the stock MLG wheels off. The grub screw looks like it has loctite on it and a 1.5 mm hex is a loose fit. I tried heating with a soldering iron, but no luck. Any tips/ tricks to getting the screw out?

[paulrkytek]

That was only for the blue grey version. The green silver version did not say that.

USA site only, Typo , 2 places states 80mm, it states 90mm under the features part of the description, no doubt lack of proof reading once again!!! It Is supposed to be a new website layout so no doubt there will be a few anomalies.

[MeyerVW]

That was only for the blue grey version. The green silver version did not say that.

[radfordc]

Motion rc site say new motor and fan.
Features:

• New! 90mm 9-blade ducted fan and powerful 3658-1920Kv brushless inrunner motor provides awesome power and incredible real life jet turbine sound

Is that an error on their end? Seems like that should say 80mm.

Pretty sure it's a typo.