Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[radfordc]

Great... "there's something not quite right..." and I haven't even flown my SU-30 yet or taken this Mig 29 out of the box...
Should I sell the Mig 29...?

Yes...most definitely sell it! After all, someone, somewhere on the internet, said something just a little critical of it. You certainly don't want to take into account the thousands of successful flights by many others.

The Mig has two known issues.... dropping flaps at high speed and high alpha lock. Both easily avoided.

[kallend]

Somebody created a set of decorative nozzles for the Mig, which might be helpful.

https://www.thingiverse.com/thing:4659231

That one has (approx) 3 degrees of thrust offset built-in (I assume it's upthrust). Would be a trivial matter in a slicer to change the thrustline.

[jasmith41]

i did buy the VT kit for it and the replacement fans Hugh W recommended - all still in the box... :)

I'm going to learn a bit on my EFlite SU-30 (that i havent' flown yet but upgraded the fans anyway) and then move to the FW mig 29...

[Airguardian]

I was another who tried tinkering with thrust line using VT trim. IMO it's not that simple. You needed *more* nose up trim on the horizontal stabilisers when on power, which was already pronounced even with a neutral CG, and then you have a funky trim change between power on/off when the h-stabs are effective.

Don't quite agree there. I replaced my nozzles with the VT ones and using the stock center marks for the nozzles the jet was immediately more balanced in thrustline. I didn't have to retrim much, if at all. If you still need to add a lot of pitch up trim, then you are likely still way too nose heavy. As a matter of fact, after installing my VT nozzles I moved the battery positions to keep the CG and I overdid it, ending up with a nose heavy CG, which quickly showed and gave me a few problems. But after moving aft the packs a tad and adding back a couple of wing rails to assist in lateral stability the plane improved substantially. It certainly flies much more aerobatic when the nozzles are enabled and you gotta be ready for that, but I didn't find the same issues that have been described here with mine.

[Evan D]

I agree 100%. While TV can get you out of alpha lock there is more than just changing the TV a couple degrees to fix the Mig all around quirkiness. I learned not to answer or argue with Jandro or others that something will work or not and just say what has or hasn't worked for me. For me a change in thrust angle was not a magic fix and I ended up putting it back to the TV centering marks.


JA, it's a very cool very large EDF. While I fully respect GG's opinion, mine is, I'd sell it in a heart beat. In fact mine went up for sale not very long after I had put the first flights on it even though I later said I'll keep it. I fly it rarely and every flight is "interesting". It is a plane I pull out when I want to show off a large, in your face, lets do tricks plane for fly in's.

FreeWing MiG-29 with TVs, upgrades.$700 - RC Groups

Somebody created a set of decorative nozzles for the Mig, which might be helpful.

https://www.thingiverse.com/thing:4659231

I was another who tried tinkering with thrust line using VT trim. IMO it's not that simple. You needed *more* nose up trim on the horizontal stabilisers when on power, which was already pronounced even with a neutral CG, and then you have a funky trim change between power on/off when the h-stabs are effective.

If it saves a plane from an alpha locked belly flop then I guess it's worthwhile, but you will be trading one set of quirks for another.

[GliderGuy]

Great... "there's something not quite right..." and I haven't even flown my SU-30 yet or taken this Mig 29 out of the box...
Should I sell the Mig 29...?

Consider (no VT kit installed):

1) I flew several thousand flights.
2) I had a blast flying her. She flies GREAT!
3) The high angle of attack alpha lock occurred 4 times in all the flying. I was able to recover 3 times.
4) The time I didn’t recover was weird wind sheer conditions. Probably should not have flown in these conditions.
5) You will miss a LOT of fun!
6) Add the vectored thrust nozzle kit, and pretty much the problem goes away. I didn’t add the VT kit because I don’t have enough channels.
7) My comment about not repairing was…”Not gonna spend $600 on parts. I will buy a new bird instead (see below).”

Your call. Just watch the videos and read and learn how to recover from it….and add the VT kit.

Would I buy another MiG-29? Yes…When I decide to buy new radio gear with more channels so I can add VT.

Would I buy another and fly her without adding VT? No. Small risk, but the gremlin is waiting to bite you as it eventually got me. VT will help keep the gremlin away.

-GG

[jasmith41]

Great... "there's something not quite right..." and I haven't even flown my SU-30 yet or taken this Mig 29 out of the box...
Should I sell the Mig 29...?

[mshagg]

Somebody created a set of decorative nozzles for the Mig, which might be helpful.

https://www.thingiverse.com/thing:4659231

I was another who tried tinkering with thrust line using VT trim. IMO it's not that simple. You needed *more* nose up trim on the horizontal stabilisers when on power, which was already pronounced even with a neutral CG, and then you have a funky trim change between power on/off when the h-stabs are effective.

If it saves a plane from an alpha locked belly flop then I guess it's worthwhile, but you will be trading one set of quirks for another.

[GliderGuy]

Since you’re not rebuilding, would you be willing to sacrifice a nozzle and measure its dimensions inside and out? I’m considering creating a set with different thrust lines to help avoid the gremlin without going to VT.

Hi Kallend,

OK...I will get the measurements done on a tail nozzle for you early next week. Unfortunately, I don't have the free time until then.

Maybe someone else has the measurements already?

-GG

[Airguardian]

It WILL work. Just need to test enough versions to nail the right thrustline.

RIP your little MiG, she was an inspiration for everyone else as to how much can an EDF jet last... now she flies higher. :)

[GliderGuy]

Not sure why you don’t quote me as I've said the same thing all along and was one of the first both flying the Mig and flying it with TVs. I know Alejandro is great and posts great videos but that doesn't mean there aren't others flying their planes too.

No doubt. AG and I were recently PMing / Top of my mind.

It wasn’t my intent to slight anyone. I apologize.

-GG

[Evan D]

Not sure why you quote me as I've said the same thing all along and was one of the first both flying the Mig and flying it with TVs. I know Alejandro is great and posts great videos but that doesn't mean there aren't others flying their planes too.

[GliderGuy]

When I put the TVs on mine I tried a turn of down thrust. It didn't help, still felt odd.

Based on AirGuardian videos and lots of flying….I don’t think a fixed nozzle change is gonna do what you want.

IMHO

The issue is getting outa alpha lock. Only certain ways to do it AG is an expert at it. It isn’t always easy to do. Pulsed throttle, no throttle, flicked sticks, etc. AND….always ALTITUDE is needed. I lacked altitude!

-GG

[Evan D]

When I put the TVs on mine I tried a turn of down thrust. It didn't help, still felt odd.

[GliderGuy]

Less upthrust was discussed, but as I recall….this opens another can of worms. I may be remembering from another forum.

Let’s see what others post about this.

-GG

[kallend]

Sure…But before I remove one, doing what you are attempting to do was discussed by several folks early on in this forum.

As I recall, the general consensus was, “It probably won’t work.”

I don’t recall all the reasons and precautions that were presented. If after you research this you still want to try, let me know.

-GG

Well, I read the forum from the beginning but I'll take another look.
Seems to me that about 5 degrees less built-in upthrust would be beneficial (of course other re-trimming would be required).

[GliderGuy]

Since you’re not rebuilding, would you be willing to sacrifice a nozzle and measure its dimensions inside and out? I’m considering creating a set with different thrust lines to help avoid the gremlin without going to VT.

Sure…But before I remove one, doing what you are attempting to do was discussed by several folks early on in this forum.

As I recall, the general consensus was, “It probably won’t work.”

I don’t recall all the reasons and precautions that were presented. If after you research this you still want to try, let me know.

-GG

[Evan D]

Moment of silence observed, she did you well with the many successful flights. I agree if mine went in I wouldn't replace her. Even with TV there's something not quite right.

[kallend]

Sadly, I am reporting the loss of my much flown and much loved MiG-29.

Gusty, wind sheer conditions just above ground level (but ok down close to the ground for landing)…

Even with the recently-installed gyro (probably didn’t have the gain set high enough), a gust hit her on base leg and increased the effective angle of attack sufficiently to put her into alpha lock. Thrust line gremlin fought against me during the attempted save.

Not enough altitude to recover….she went in hard on pavement. $600 for parts to fix. Mmmmm NOPE!

I’m thinking this MiG has the most flights anywhere with several thousand. This flight record proves the bird is a very good design, and would have flown much more, IF ONLY!

A moment of silence for the “likely” record holder may be in order. LOL

Ummmm….Lessons learned??? Installing VT would probably be a good idea, if you haven’t. VT would have saved her! Why? The thrust line gremlin is waiting to bite you.

-GG

Since you’re not rebuilding, would you be willing to sacrifice a nozzle and measure its dimensions inside and out? I’m considering creating a set with different thrust lines to help avoid the gremlin without going to VT.

[GliderGuy]

Sadly, I am reporting the loss of my much flown and much loved MiG-29.

Gusty, wind sheer conditions just above ground level (but ok down close to the ground for landing)…

Even with the recently-installed gyro (probably didn’t have the gain set high enough), a gust hit her on base leg and increased the effective angle of attack sufficiently to put her into alpha lock. Thrust line gremlin fought against me during the attempted save.

Not enough altitude to recover….she went in hard on pavement. $600 for parts to fix. Mmmmm NOPE!

I’m thinking this MiG has the most flights anywhere with several thousand. This flight record proves the bird is a very good design, and would have flown much more, IF ONLY!

A moment of silence for the “likely” record holder may be in order. LOL

Ummmm….Lessons learned??? Installing VT would probably be a good idea, if you haven’t. VT would have saved her!

Why? The thrust line gremlin is waiting to bite you.

-GG