Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[Shaun Evans]

And not too many RC jets use hydraulics to move control surfaces.

True.... but neither do Piper Archers (or a whole host of other production FS aircraft with FFS that aren't balanced on the pivot.

[kallend]

True.... but neither do Piper Archers (or a whole host of other production FS aircraft with FFS that aren't balanced on the pivot.

At the risk of repeating what has been written a number of times already, no-one is suggesting balancing this MiG's FFS on the pivot.

The relevant design feature in this MiG is that the pivot is way ahead of the CP of the FFS, leading to large loads on the elevator servos and supporting structure when the CG is at the specified position, which (almost) everyone agrees is way too far forward.

[Shaun Evans]

At the risk of repeating what has been written a number of times already, no-one is suggesting balancing this MiG's FFS on the pivot

Hmm

OK, my mistake then. I could have sworn I read something else somewhere in this thread. If that's the case, I'm good to go since I've already upgraded the servos, linkage and a few other items I was alerted to here.

Cheers!

[fredmdbud]

A consideration is the servo/actuator load during "steady state" (normal) flight, compared to max loading which is burst/momentary - unless you are the full-throttle-anything-but-a-straight-line pilot. It's not desirable to have the servos working more than they have to during the majority of the flight. An overworked servo has less mechanical and thermal margin for such peak loads.

[xviper]

True.... but neither do Piper Archers (or a whole host of other production FS aircraft with FFS that aren't balanced on the pivot.

What's that got to do with a military jet (real or RC)? A Piper Archer is an egg beater that can easily be muscled with non-hydraulics using human strength. A real military jet goes fast, has heavy control surfaces and needs hydraulics to operate. This model Mig equivalent is like having a tiny little human (servo) trying to yank on that elevator. You like calculations. Why don't you do the calculations to see the comparison.
Anyway, these sorts of advanced engineering discussion really don't have much impact on a little model airplane. It's like someone trying to use a tiny little measuring tape to measure a Barbie doll's boobs to determine if they are scale.

[Shaun Evans]

What's that got to do with a military jet (real or RC)?

Lol, really? I thought we all understood that the principles are pretty much universal. Anyway, I thought you mentioned hydraulics as some sort of explanation about why no planes have FFS with a balance point on the pivot. I've heard that one many times before....

Piper Archer is an egg beater that can easily be muscled with non-hydraulics using human strength.

What's that you were asking about 'what's that got to do with...?'

You like calculations. Why don't you do the calculations to see the comparison.

I'll leave you to it, thanks.

these sorts of advanced engineering discussion really don't have much impact on a little model airplane.

Uh... if you say so.

It's like someone trying to use a tiny little measuring tape to measure a Barbie doll's boobs to determine if they are scale.

Again, I'll leave you to it. My current engineering project has more to do with trouble-shooting certain systems on FS F-35's than with Barbie's boobs, so I'll take your word for it. Have a nice day!

[Airguardian]

More MiG-29 shenanigans:

Many of the FFS in full size aircraft (example Piper) incorporate “anti-servo” tabs on the trailing edge of the FFS to provide “resistance” to the control movement. This is done so the pilot gets “feel” feedback and thus avoids over stressing the airframe by deflecting the FFS too much.

There is often an even more direct and pressing reason to require tabs on the control surfaces of aircraft, and not just on FFS.
Particularly in aircraft that have a direct 'control-line' between pilot and control surface, you want to design aircraft so that they remain rather stable when hands-free, this is slightly different of how our model airplanes typically work as the servos fix a neutral position when the stick is centered. So tabs are designed and added so that they change the hinge moment around a control surface, meaning that the 'neutral' position in flight (hands-free) will depend on speed and tab trim. The tab can be designed either so it alleviates pressure on the stick as the pilot takes it away from the center (for example on planes that would otherwise require excessive force) or to make it feel more locked and requiring more force from the pilot (on planes that would otherwise feel no force-feedback at all)... so it all depends on the plane design and what one intends to achieve. Changing the mechanics of how these tabs move in function of control surface deflection has a direct impact on the stability features of the aircraft and the force-feedback on the stick. And it's also a great solution for aircraft trimming.

In our case with the pivot being so far forward is it possible to get it reasonably balanced?

Mass balanced or aerodynamically balanced?
Mass balancing would be easy enough to achieve although probably pretty useless. Haven't heard of any FW MiG-pilot suffering from flutter on their stabs. It would alleviate a bit of pressure from the stab servos but not that much.
Aero-balancing can't be changed without changing the pivot axis one way or another.

Anyway, these sorts of advanced engineering discussion really don't have much impact on a little model airplane. It's like someone trying to use a tiny little measuring tape to measure a Barbie doll's boobs to determine if they are scale.

Ignorance speaking.

Lol, really? I thought we all understood that the principles are pretty much universal.

Some people around here think there exists a whole separate set of laws of physics that apply to model aircraft and model aircraft alone, lmao.

As for mass-balancing stabs and your history of the 'oh-so-sure-of-himself-sponsored-pilot', you can point out to him next time that he takes a look at the resting position of full flying stabs on fighter jets when the engines are off.

[GliderGuy]

Hi Airguardian et al....

So there is no confusion, the anti-servo tab may (and typically does) “also” function as a trim tab. But the primary purpose of the anti-servo tab is to “fight the pilot’s inputs” and fight him harder as the deflection amount increases. You can see how this would be the case(photo and video). As the stabilator trailing edge moves more...the anti-servo tab moves even more. They move as if in symphony-always moving with each other.

While a normal trim tab....the pilot uses these to prevent him having to “hold” a control in a given position. He lets the trim tab do it for him. However, by tweaking the position of the anti-servo tab with a separate trim control, the anti-servo tab may be made to have the dual function of a trim tab.

Short video....

https://m.youtube.com/watch?v=fo8rj-T0P5I

-GG

[Airguardian]

What you say is correct but 'anti-servo tabs' are not the only type of tabs that exist.

Anti-servo tabs work opposite to servo tabs. My comment was meant to cover both.

https://en.wikipedia.org/wiki/Servo_tab

Again, as I was mentioning, these can be used in a number of ways to different ends depending on the aircraft design and features.

[GliderGuy]

Perfect! All bases are covered for this FYI topic. Thanks. Now....back to the MiG / LOL

-GG

[Sky Wolf]

So we have two people in the company, Derek in CS and "reliable source", giving contradictory information.

If Derek's information is wrong, that's a black mark for the company for "officially" misrepresenting the facts.

For what it's worth, RC-Castle, another authorized Freewing distributor, has it "out-of-stock". When the 90mm Yak-130 was discontinued, it was tagged as "discontinued", not "out-of-stock".

Guess the rumor mill is daily grist some.

Hey there Fred, glad to hear ya Bud! I agree about the labeling at RC-Castle. Just spoke with another source at Motion and they said that obviously someone has gotten some incorrect information regarding discontinuing the MiG-29. They are wondering where this source got it’s source of information. The manufacturer has been slow to respond to timelines because of the reasons and circumstances surrounding how far behind all of the manufacturers are at the moment.

Still hopeful though that a newer version is being worked on.

I hope the two sources I heard from are correct and not the source that said it’s being discontinued. I actually think it would be a darn shame if whoever said it’s being discontinued would actually tell that to someone outside the company. What a mark that would be on Mark and Tom!

The only company that I ever experienced that with (keeping a plane listed as “Out of Stock” when it was actually discontinued) was BH. Hopefully other RC companies learned from how they treated us in the past. And I don’t think MRC has done that...have they?

[xviper]

Ignorance speaking.

Sorta like your "Hey, look at me, I'm so needy, please, please subscribe to my channel, I put so much work into it, I want to be an internet sensation and influencer". That's why I had you on IGNORE for a long time but then I took you off just so I can read the ridiculous, goofy crap you post. Nothing you say or do means Jack Schitt to me. I guess back to ignore.

[Airguardian]

Ah, so that's what it's all about.
I'm glad you cleared it out.

Maybe I'm needy, maybe not. What the hell would you care or would it have anything to do with the topic at hand?

FWIW, and with all honesty I don't spend hours on end, here in the forums just to become an internet sensation or influencer of sorts.
I'd be wasting my time if that's all I cared about. I really feel sorry for you if that's all you can work out about me.

[kallend]

Perhaps someone would enlighten us by telling us which laws of physics do not apply to model aircraft.

[Airguardian]

SUCTION, of course!

(Ill attempt at humour with an insider-joke to deescalate)

[Evan D]

Has someone said the big MiG has been or is being discontinued?

Hey there Fred, glad to hear ya Bud! I agree about the labeling at RC-Castle. Just spoke with another source at Motion and they said that obviously someone has gotten some incorrect information regarding discontinuing the MiG-29. They are wondering where this source got it’s source of information. The manufacturer has been slow to respond to timelines because of the reasons and circumstances surrounding how far behind all of the manufacturers are at the moment.

Still hopeful though that a newer version is being worked on.

I hope the two sources I heard from are correct and not the source that said it’s being discontinued. I actually think it would be a darn shame if whoever said it’s being discontinued would actually tell that to someone outside the company. What a mark that would be on Mark and Tom!

The only company that I ever experienced that with (keeping a plane listed as “Out of Stock” when it was actually discontinued) was BH. Hopefully other RC companies learned from how they treated us in the past. And I don’t think MRC has done that...have they?

[GliderGuy]

Has someone said the big MiG has been or is being discontinued?

It does NOT appear that is the case.

-GG

[Evan D]

Fred was talking about the Yak when he said discontinued and I think Wolf thought
he was talking about the MiG. From what I was told FreeWing asked retailers to hold sales pending
an investigation, a big difference to being discontinued.

Either way it would be good to know what’s really happening and not second hand info.

[xviper]

Either way it would be good to know what’s really happening and not second hand info.

Wouldn't that make the internet a much better place to be. We see second hand info being passed off as fact (The World According to Garp.) Then there's "Googling stuff" and passing that off as one's own intellect. Truth on the internet is NOT always out there.

[mshagg]

Anything other than "they're awaiting stock" should be discounted as unfounded speculation. That includes hearsay suggesting they're doing testing, considering revisions to the design or witholding the jet from sale due to feedback, as we have heard from unverified sources.

If help desk staff are confusing the message as has been suggested, Motion might consider tidying up the communications around the model and ensure advice provided to customers is consistent with the official position. Along with the usual rumour mill stuff there are actors who are happy to promote the speculation as fact to the extent it suits their (negative) narrative about Motion/Freewing.