Official Freewing 80mm MiG-21 Fishbed Thread

[RCjetdude]

You may have been losing a considerable amount of efficiency and therfore performance. I hope you have it sorted out.

[gooniac33]

RCjetdude....this is my first delta wing... I agree they do fly different. That is one reason this airplane appealed to me. I do like to go fast though!! Maybe now that my fan unit is cleaned up I'll be pleasantly surprised. Not sure how long it's been that way.

This plane has a huge CG range! I started out flying my plane way too nose heavy and it took a long time to rotate and get airborne. I have since moved my battery back a good 6 inches and now the plane has come to life! I can also use full flaps for take off with no issue. It is in the air in about 50-60feet in its current state. No adverse affect on handling at all. It works just the same as before but with better pitch response, shorter take offs and much slower landings. It is just an all around amazing plane!

[DCORSAIR]

Okay, convinced, going to order one soon, didn't want another 80mm but want to fly the Mig.........:)

Gooniac, you moved the battery back 6 inches??:Scared:

[cashmoneybrother]

[RAPHAEL_CINTRA]

Good day people,

This weekend i painted and build my Mig.

For the paintaing, i choosed a simple version just to have a better reference in the sky...red, Russian version.
Everything runned just fine during all the processes, and the plane is almost RTF/Maiden (3 position D/R+Expo and CG and etc)...unfortunately i noted that some times the servos present a very small/fast moviment (like some micro glitches) :-( .... they don't freeze/stop and neither desarm the RX (maybe some "noise" due the several long wires)...but i'm concerned...maybe due the long wires of this plane, this can happend (i don't think is a servo problem...i cycled all with a servo tester in the automatic for about 10 minutes before the assemble)...i dont think the paint job can affect.
During this week i'll try to test some actions: 1. Baypass AIL, ELE, FLAP and RUD from blue box (brand new Y's), 2. Use a different RX (i'm using a Futaba 14SG with R7008SB FASTest HV RX)...3.roll the servos wires in a ferrite ring (filter the noise) i'll took from a old ESC (don't know if i will try to roll all the servos or just the elevator or the esc...honestly i don´t know).
Thank you all and safe flights

[TiredIronGRB]

Good day people,

This weekend i painted and build my Mig.

For the paintaing, i choosed a simple version just to have a better reference in the sky...red, Russian version.
Everything runned just fine during all the processes, and the plane is almost RTF/Maiden (3 position D/R+Expo and CG and etc)...unfortunately i noted that some times the servos present a very small/fast moviment (like some micro glitches) :-( .... they don't freeze/stop and neither desarm the RX (maybe some "noise" due the several long wires)...but i'm concerned...maybe due the long wires of this plane, this can happend (i don't think is a servo problem...i cycled all with a servo tester in the automatic for about 10 minutes before the assemble)...i dont think the paint job can affect.
During this week i'll try to test some actions: 1. Baypass AIL, ELE, FLAP and RUD from blue box (brand new Y's), 2. Use a different RX (i'm using a Futaba 14SG with R7008SB FASTest HV RX)...3.roll the servos wires in a ferrite ring (filter the noise) i'll took from a old ESC (don't know if i will try to roll all the servos or just the elevator or the esc...honestly i don´t know).
Thank you all and safe flights

Looks fantastic, I really need to get one of these!

[RAPHAEL_CINTRA]

Looks fantastic, I really need to get one of these!

Thank´s Tired.
Is a simple painting job, just to avoid loosing it on the gray sky.
It´s bigger than appears...great model indeed.
Now i´m focused to solve this small/independent servos moviments...they are occasional...hopefully will be a RX issue (this Futaba RX i installed have telemetry...i´ll try a more simple SFHSS one)...need piece of advice on this from the most experienced will be great :-)
You need one MIG also!
Safe flights

[RAPHAEL_CINTRA]

Good day all,

Yesterday i made the test and, yes, the servos twitches come from the HobbyEagle gyro (in my case A3-L), no matter ON or OFF...if the connection passes through the gyro, there's the twitch...nothing related to the blue box, at all...when i connected directly from BB -> RX no twitch...anyway i'll maintain the gyro.

My attention now is within the CG. I measured 275mm (as per image, green circles...comparing with other pilots images it's seems to be right) and i'm using the GensAce 5500 45C (755gr)...i'm seeking the "sweet spot" but must confess that i'm strugling more with this model than other ones wich i presume is because of the delta wing) to keep it perfect leveld...i attached some pictures for our collegues to comment if i'm doing in the right way...i know this plane can handle CG differences but i want to avoid any risk or big mistake.

I'll be thankful to receive some comments about the battery placement, if possible.

Thank you all and safe flights

[bill34207]

The Mig is a lot easier to balance inverted since in essence, it is a low wing model. I'm really amazed that you managed to get your Gens Ace 5500 pack to go in flat. I run the same packs in mine but have to stand them on their sides.
I can check after I get home and see where my location is.

[Itgordon00]

Thanks everyone for your suggestions! All good ones! To my surprise I did find considerable amount of grass and gum build up in my fan which I'm not sure how but it went unnoticed before my last flight. I took the fan apart and cleaned it up and sprayed a thin coating of graphite lubricant on the housing to try to prevent grass from sticking. I'm going to mow the field as close as I can and see how it does.
Itgordon00... I'm using pulse 5000 60c I must say they're an expensive battery but I fly them in my helicopter and they have given me very good service. I'll be looking forward to your video on grass

Jet10,
I flew off grass this weekend. It was not pretty but it did it...bearly. I needed flaps. I struggled with rotation so i suspect that that Mod with the wooden wedge to keep the nose up will help. Definitely would not have rotated with the tanks. It made me appreciate my paved runway even more.

[RAPHAEL_CINTRA]

The Mig is a lot easier to balance inverted since in essence, it is a low wing model. I'm really amazed that you managed to get your Gens Ace 5500 pack to go in flat. I run the same packs in mine but have to stand them on their sides.
I can check after I get home and see where my location is.

Hey there Bill,
Thank you very much for your reply.
Honestly i was planning to use the battery "upright", probably like you use yours...is more confortable to move around for sure. Anyway as you can see it fits like these, but very tight. Maybe i´ll use upright in the end.
Yes please, if you can send me images (with some measure) about your placement it´ll help me a lot! Considering that you use the same battery (gensace 5500 45c) i´ll follow the same place you´re using and will test inverted like you do (retracts extended?).
Cheers and safe flights

[gooniac33]

Okay, convinced, going to order one soon, didn't want another 80mm but want to fly the Mig.........:)

Gooniac, you moved the battery back 6 inches??:Scared:

I started way too nose heavy because I didn't trust the manual at first. Had a huge pack and it was way forward... It is now just barely being held by the battery strap and the plane is very happy! I got a lot of flights this past weekend and here are some of my faves....

[RAPHAEL_CINTRA]

I started way too nose heavy because I didn't trust the manual at first. Had a huge pack and it was way forward... It is now just barely being held by the battery strap and the plane is very happy! I got a lot of flights this past weekend and here are some of my faves....

Very very good Gooniac!
You seem very relaxed and comfortable with this model...maybe due the tons of flight you already made.
Landings are 10/10! Touch and go was also superb!
Great!!!!

[Alpha]

I wish I could watch these videos from where I'm at right now.


Cashmoneybrother, I really like your centerline tank. It's a good look on this aircraft, and aids visibility, too. I did the same with one of my Freewing 80mm Mirage models.

[Jet10]

Anyone flying on grass be certain to check your fan every flight to make sure it did not pull grass in the underside intake. The front wheel picks the grass up and it gets sucked right in.. any amount of grass stuck to the webbing in the shroud really reduces performance. Our field was mowed as short as I could get it and I was pleased with the way it performed. I'm starting to really like the airplane!

[bill34207]

Hey there Bill,
Thank you very much for your reply.
Honestly i was planning to use the battery "upright", probably like you use yours...is more confortable to move around for sure. Anyway as you can see it fits like these, but very tight. Maybe i´ll use upright in the end.
Yes please, if you can send me images (with some measure) about your placement it´ll help me a lot! Considering that you use the same battery (gensace 5500 45c) i´ll follow the same place you´re using and will test inverted like you do (retracts extended?).
Cheers and safe flights

Got home from work and shot some quick pix of battery location and my CG point. More information shows when photos are opened.

[RAPHAEL_CINTRA]

Got home from work and shot some quick pix of battery location and my CG point. More information shows when photos are opened.

Thank you very much Bill! You really helped me a lot with the images and complete explanation.
As i can see on your image 2, your battery is ending around 4'1/4" (~ 110mm) from the "canopy behind wall" right? Also based on the velcro strap, is clear that your battery is ahead of mine ( mine 3' 3/8" or ~ 85mm).
Your CG dot (your image 1) is 275mm from the wing leading edge?
I'll update my CG dot after your reply, reposition my battery like you showed and return with the results.
Cheers

[bill34207]

My digital caliper doesn't go big enough to measure that far. It's 10-5/8" from wing leading edge at the root to the mark. Running that through the calculator it's around 270 mm. This model is pretty forgiving on CG.

[RAPHAEL_CINTRA]

My digital caliper doesn't go big enough to measure that far. It's 10-5/8" from wing leading edge at the root to the mark. Running that through the calculator it's around 270 mm. This model is pretty forgiving on CG.

Great!
I´ll run some CG tests/battery placement this evening and i let you know.
Safe flights
Cheers

[DCORSAIR]

Got my Mig 21 ordered, it will be here next Thurs. Wasn't going to do another 80mm but it looks like fun so I had to try one. Will be asking questions I'm sure......:Cool: