Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[mshagg]

That still doesn't tell me if flexing is actually observed, rather than supposed/conjectured/post-mortem'ed. Sounds more like "oh, s#!t, I'm gonna beef them up because it happened with another plane."

If that works for you, fine. But since I'm not going to soup mine up with 6000mah batteries, hotter motors, afterburners and the like, I'm opting not to go overboard, and see if I find observable evidence.

I make no representations as to the effect on flight characteristics, but there's visible flex in the stock setup which is simple enough to test yourself (I've since added heavy duty servo horns which addressed some of the observed flex):

For the sake of a few bucks I'm currently putting similar setups on all of my larger freewing birds with full flying stabs. Piece of cake for piece of mind.

[john2kx]

Replaced mine with DuBro links, 4-40 all thread and smaller carbon rod than factory piece. Stabs had about 3/16” play originally. Upgrade reduced play by 75%.

[Jet jocky]

R u threading into carbon fiber rod or is the rod passing all the way through it?

[john2kx]

The carbon rod slides over 4-40 piece. I added a few drops of medium CA to secure carbon rod at both ends. The 4-40 rod removes the majority of play. The carbon is more for looks.

[JCheek]

Doesn't this plane already have carbon fiber sleeves for the control rod?

One simple test will prove if there is flex - press down on the elevator and see how much pressure will cause an elastic bend, if any at all.

Yes it does but mine had very noticeable flex when doing exactly what you suggested. Mine flies like a totally different plane after changing the linkages. Most of the flex shows up in the very end where the clip goes on the bent end.

[Airguardian]

I make no representations as to the effect on flight characteristics, but there's visible flex in the stock setup which is simple enough to test yourself (I've since added heavy duty servo horns which addressed some of the observed flex):

Great info coming up here...
Also looks like a great deal of the flex comes from the servo horn being too thin and flexing, more so than the linkage itself (Which it also clearly does).

May consider this upgrade myself.

[xviper]

I make no representations as to the effect on flight characteristics, but there's visible flex in the stock setup which is simple enough to test yourself (I've since added heavy duty servo horns which addressed some of the observed flex):

For the sake of a few bucks I'm currently putting similar setups on all of my larger freewing birds with full flying stabs. Piece of cake for piece of mind.

It looks (at least to me) that any flex there is, is in the plastic servo horn. Perhaps if that is a concern, find some metal horns.

[xviper]

I made a stand for the MiG out of the styrofoam box it came in. I cut it down with a hot hacksaw blade so that the plane could sit on it’s flat surface. The stand was just wide enough to allow the main gear to come down and just short enough so the nose gear could come down unimpeded. The whole plane rested on the two belly bulges. It’s much more stable than that HobbyKing stand. Also, those styrofoam stands you buy at the hobby shop is not the right shape for the MiG to sit on.

It ain't purdy, but it works. Since I already paid for it when I bought the model, why not use it? Imagine the MiG pointed towards you in the picture, with it's "skids" resting near the edges of the box. Wheels can come down without touching the box or the ground (should you put it on a set up table or right on the ground). Did a similar thing with my AL-37 - even the correct shape for the big fuse. But if you need to spend extra money before you think it's worth it, then you don't want to do this. I have a standard foam Robart stand for all my other planes.

[radfordc]

Inverted too

[GliderGuy]

Good video mshagg. I notice that a significant amount of the plastic servo arm flex is prevented by the Du-Bro safety lock quick link.

Some report a perceived softness pulling out of loops at the bottom. This overall flex might be the cause.

With the upgraded link+pushrod+stronger servos, I perceive a nice crisp loop recovery response.

-GG

[john2kx]

Replaced mine with DuBro links, 4-40 all thread and smaller carbon rod than factory piece. Stabs had about 3/16” play originally. Upgrade reduced play by 75%.

I found no play at control horns with setup I used and the upgraded servos with supplied horns.

[GliderGuy]

I found no play at control horns with setup I used and the upgraded servos with supplied horns.

No doubt - The 4-40 rod + Du-Bro hardware with or without a carbon tube sleeve (for looks) is a worthwhile addition. I also have very little play (tiny) using the stock servo arm.

-GG

[leithalweapon]

I did what Glider Guy did except I used rods that were threaded on one end and I soldered a threaded end onto the other side of the rod.
At first I was cursing GG, because I droped one of the clips for the quick clip clevis. Took about 20 minutes of crawling around the floor with a tac light to find it. After it was all installed the dubro quick clip clevis does keep the servo horn from flexing.
Overall the elevators go from having a ton of slop to feeling very rigid.

[radfordc]

I can be so dumb! I couldn't understand why my jet rolled so slowly when everyone else was saying it was sensitive in roll. Also my pitch control just didn't seem as positive as I would like. Today, while fooling around with my transmitter settings the penny dropped....I had copied over the model settings for another jet to use as the start for setting up the Mig. In the process, I completely forgot to check the rates/expo settings. I've been flying the Mig with the ailerons on 50% rates and all the controls on 50% expo. After fixing this, guess what, the plane flies much better.

[JLambCWU]

Roger that....loved your photos. Thanks for the details.

Soooo....What’s your take on the “mysterious” crashes?
-GG

Honestly there is no mystery. Two I’ve seen so far where people said they suddenly lost control, that are clear stall/spin.

As hard as it is to slow the model with its extra battery/weight for people not used to it, once you get it slow it bleeds energy really fast and you have to be on top of it.

Theres been honestly very few crashes compared to previous releases, and most are from people who aren’t ready for the aircraft, or have set it up outside of the manuals recommendations.

[JLambCWU]

Duplicate

[mshagg]

At first I was cursing GG, because I droped one of the clips for the quick clip clevis. Took about 20 minutes of crawling around the floor with a tac light to find it.

This mirrors my experience to the point where it's creepy lol.

[leithalweapon]

Honestly there is no mystery. Two I’ve seen so far where people said they suddenly lost control, that are clear stall/spin.

As hard as it is to slow the model with its extra battery/weight for people not used to it, once you get it slow it bleeds energy really fast and you have to be on top of it.

Theres been honestly very few crashes compared to previous releases, and most are from people who aren’t ready for the aircraft, or have set it up outside of the manuals recommendations.

Have any of the crashes on video seem like they were going slow? None of the first crashes in asia lookrd they were slow enough to stall with the nose level on the horizon.

[janmb]

Great info coming up here...
Also looks like a great deal of the flex comes from the servo horn being too thin and flexing, more so than the linkage itself (Which it also clearly does).

May consider this upgrade myself.

I definitely am as well.

4-40 turnbuckle, and ball links in both ends for me. (got threaded, metal servo horn and corner screws for the servo, so don't mind the increased arm. Otherwise, clevis in the servo end would be better)

[janmb]

Have any of the crashes on video seem like they were going slow? None of the first crashes in asia lookrd they were slow enough to stall with the nose level on the horizon.

Correct, they were not slow at all. In fact, most videos we have seen of crashes this far, with a couple of clear exceptions, have not been slow or in any sort of stall scenario what so ever.


And no matter how much he likes to talk about it, Justin has exactly zero basis for any claims on how much this model crashes compared to other releases. Nor do I, but unlike him, I'm not making claims on that point either.