Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[janmb]

My tip would be: They are mandatory. Do it :-).

Big +1. Not using tailerons should be punishable imo

[Evan D]

Whether or not this plane has servo issues with the upgraded FW servos is yet to really be proven. That said if you don't trust something, anything... ESCs, BEC, wiring, the MCBe, then it's on you to do something about it or accept it and hope you are wrong.

That said, I've had tailerons since day one even when I flew before getting the upgraded FW servos. I had enough trust in them to fly and then put the upgraded ones in and finally am now on stronger Corona servos. Either way I would not fly this or a few other jet without tailerons, it just make it fly and maneuver so well.

Just curious, why on a jet that may already have elevator / elevator servo issues would you want to add additional responsibility to those possibly flawed parts? I understand the argument for a better flying jet or even for a more scale control surface setup but with tailerons if I was to, for example bank left while climbing (typically how most take offs go at my field due to the treeline) my right elevator would be put under quite a bit more stress due to it being more deflected than the left. At least as just elevators the stabs work together to do the same job but in a taileron configuration one servo can be working much harder than the other possibility increasing the chance of failure. I'm no full scale pilot nor do I have any degrees in aerodynamics, just the way it seems to me. Let me know if I'm not looking at this right. 🤷♂️

[Airguardian]

Airguardian only because your flights are so smooth and relaxing, not a knock on the video.

Hey, hey!
I didn't take it as an offense! :)
I was just going along with a joke of my own... (Only that it actually turns out it's not just a joke, rofl. Dad has a tendency to get asleep with my videos... and not just!)... So they have indeed a soothing or trance effect on some.

Let me know if I'm not looking at this right. 🤷♂️

Yep, you are not looking at it 'right'.

'Normal commands' are not really tough on the stabs because the jet modifies its attitude and trajectory. The very act of moving the stabs cause the jet to move in a fashion that the 'wind' as seen by the stab will mostly always be at a small angle of attack, so the loads are really, really low.

The problem arises from flap usage because the imbalance in pitching moment by the flapped wing gets compensated by the stabs. The jet cannot further 'align' the stabs to the 'incoming wind' so to speak, because both moments pretty much cancel each other, so from the outside the jet flies straight and all seems alright but the loads on the stabs increase tenfold. If you are not willing to use tailerons for this (foolish IMO) reason, you may just as well go and lock your flaps in permanent up position because their effect on the stabs is order of magnitudes greater than what you may achieve by symmetrical or differential deflection of the stabs alone in normal flight.

[nuts-n-volts]

edit, sorry.

[nuts-n-volts]

Yep, you are not looking at it 'right'.

'Normal commands' are not really tough on the stabs because the jet modifies its attitude and trajectory. The very act of moving the stabs cause the jet to move in a fashion that the 'wind' as seen by the stab will mostly always be at a small angle of attack, so the loads are really, really low.

The problem arises from flap usage because the imbalance in pitching moment by the flapped wing gets compensated by the stabs. The jet cannot further 'align' the stabs to the 'incoming wind' so to speak, because both moments pretty much cancel each other, so from the outside the jet flies straight and all seems alright but the loads on the stabs increase tenfold. If you are not willing to use tailerons for this (foolish IMO) reason, you may just as well go and lock your flaps in permanent up position because their effect on the stabs is order of magnitudes greater than what you may achieve by symmetrical or differential deflection of the stabs alone in normal flight.

I am trying to follow that, but I just don't think that is the problem. I have flown this jet at full power, flaps down for a full lap and more and it does not exhibit a problem. I did beef up my electrical to all flight controls. I do believe earlier crashes were most likely caused, among other things already discussed, insufficient voltage to the elevators. Physical loads transferred into electrical loads, small gauge wiring with long runs, 5.1 volts spread out over many servos. It's not just one thing. It's quite a few actually. Take the time to get 'em all right and this jet will fly great for you.

[Evan D]

Not sure it matters but I’m still running the stock BEC and now the TVs. And tailerons.

[nuts-n-volts]

I think it's a build up, Evan. You could be fine with stock voltage. Certainly, many are. But, if pushed in all the different categories, and especially at high power, I do believe it 's a possibility anyway. Just my thoughts.

I will say, I don't have any fear pushing the -29 with full flaps out, or any other condition.

[Airguardian]

That's beside the point. I was not debating now whether this was causing the crashes, just pointing out that flaps-down is much more heavy on the stabs than taileron mixing.

[Nickc2023]

Not sure it matters but I’m still running the stock BEC and now the TVs. And tailerons.

How many channels in your reciever to be able to do tailerons and TV?

[nuts-n-volts]

Oh ok. I get that.

[Evan D]

You need three to do TVs and have them on a switch. You need one extra for tailerons. 6+3+1 is 10.

I also have crow and separate steering on 12ch. At some point I’ll put in a 9+8 expander to put my rudder air brakes and full span ailerons back on it.

[Nickc2023]

Hey, hey!
I didn't take it as an offense! :)
I was just going along with a joke of my own... (Only that it actually turns out it's not just a joke, rofl. Dad has a tendency to get asleep with my videos... and not just!)... So they have indeed a soothing or trance effect on some.




Yep, you are not looking at it 'right'.

'Normal commands' are not really tough on the stabs because the jet modifies its attitude and trajectory. The very act of moving the stabs cause the jet to move in a fashion that the 'wind' as seen by the stab will mostly always be at a small angle of attack, so the loads are really, really low.

The problem arises from flap usage because the imbalance in pitching moment by the flapped wing gets compensated by the stabs. The jet cannot further 'align' the stabs to the 'incoming wind' so to speak, because both moments pretty much cancel each other, so from the outside the jet flies straight and all seems alright but the loads on the stabs increase tenfold. If you are not willing to use tailerons for this (foolish IMO) reason, you may just as well go and lock your flaps in permanent up position because their effect on the stabs is order of magnitudes greater than what you may achieve by symmetrical or differential deflection of the stabs alone in normal flight.

Thanks Airguardian. It's not that I'm unwilling, I just haven't done it before and I like to try to better understand things before I do em. I have a couple dozen flights on my mig with no problems so I don't have a reason not to trust it. I have done many of the mods suggested in this thread just to be on the safe side. I really like this mig and don't wanna lawm dart it because I over looked something. Thanks for the info.

[Nickc2023]

You need three to do TVs and have them on a switch. You need one extra for tailerons. 6+3+1 is 10.

I also have crow and separate steering on 12ch. At some point I’ll put in a 9+8 expander to put my rudder air brakes and full span ailerons back on it.

Wow. You've got a lot going on there! I guess my 8ch rx isn't gonna cut it!

[Evan D]

Yeah, you’ll loose something. Easiest would be to Y the yaw TV servos to the rudder and have the pitch and roll TV servos on a switch.

[Evan D]

Or do tailerons and Y the P&R TVs to them. But no way to switch of TVs. I’ve been flying mine on all the time anyway but for the first flights I wanted a safety switch.

[xviper]

Wow. You've got a lot going on there! I guess my 8ch rx isn't gonna cut it!

It depends on how you want to do it and how much separation of all the control surfaces you want and whether or not you want anything on a switch. Here's the minimum (not necessarily by channel number):
1. Throttle
2. AIL (left/right Y'd together)
3. Rt. taileron with Rt. VT Y'd to it.
4. Lt. taileron with Lt. VT Y'd to it.
5. Steering, rudder, VT rudder all Y'd together.
6. gear.
7. flaps.
If you want to go nuts and do everything separate and put in a switch or two, then you'll need 11 or 12 or more channels (save an extra channel for the kitchen sink). Or you can just use the KISS principle. Personally, I don't need or want tailerons, nor do I want to shut off anything and I can do it with 6 channels.

[Evan D]

How can you do standard elevators and TVs with 6?

[kallend]

How can you do standard elevators and TVs with 6?

Some gyros would enable the necessary mixing. I could do it with my HobbyEagle A3S2 or A3S3.

(Assuming I'm understanding the question correctly).

[Evan D]

He said 6, which to me is the normal TAERGF. Wondering how he, Xviper, was thinking of doing it.

Can you plug a Hobby Eagle into that and get pitch and roll outputs for the TVs? Maybe with two of them? Yaw TV can be Y'd... Maybe with other gyros like the Demon Cortex or the one Flex uses.

[kallend]

He said 6, which to me is the normal TAERGF. Wondering how he, Xviper, was thinking of doing it.

Can you plug a Hobby Eagle into that and get pitch and roll outputs for the TVs? .

Sure. Set it up for "elevon" mixing but send the outputs to the TVs. Even a cheap** A3PRO could do it.

AND you end up with pitch and roll stabilization on the TV nozzles.

** $34 from Amazon, less elsewhere.