Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[radfordc]

What are you meaning by the acronym SWAG? I would use that looks about right...

Probably "scientific wild-assed guess" Hopefully not some of the others... http://209.197.79.194/meaning-definition-of/swag

[ColtPilot]

Thanks for the reply. It's mostly what I assumed. We have to be careful what we post and it's context. I was really looking for your setup specific to the MiG, what I got from the below is you are not using a gyro, have not set throws per the manual but to your liking (not a bad thing), added AB lights, good to know for balance but knowing what batteries you are using would be better info, and no major components have been changed.

Have you added any reflex? You say you have now changed servos, which ones and to what? Have you altered any pushrods?

How many flights do you have now? Are you happy with it or still adjusting?

By the way any time someone starts out with "Doing this for 50 years" I roll my eyes. I've been doing it for at least that long and have seen many people that even after that long have no clue in general or about specific things. We are all learning, or I hope we all are. I subscribe to the mantra of you don't know what you don't know with a sub mantra of those that think they do (know everything) are stupid. I'm not saying that about you specifically.


What are you meaning by the acronym SWAG? I would use that looks about right...

Scientific Wild Ass Guess (my dad's words)
As far as rates go, 100, 85, 70 starting at the middle for first flights. This is a model and never had a crash due to radio failure. Had a servo wire chaff through causing a crash. Mostly dumb thumbs. Linkage hook up by the book. I did learn how to use flight mode for flap to elevator trim mix so as not to deal with percentages. Makes for precise input when flaps and gear deploy. I've CG'd 4 planes in this hobby with excellent results. Never had reversed ailerons. Airframes and flight control tech on Navy jet aircraft. Re-rigged 40 T2-C Buckeye's due to a stall spin issue. Fixed the problem due poor maintenance from persons not following the book before me. So I do know what I know and do learn new skills daily. Private pilot since 1979 with 600hrs TT. From jet mech to air traffic controller retired. Now doing OSHA work in training and site safety. 2 more years total retirement. Can't wait.

[leithalweapon]

Reads like an obituary. He was a wonderful man. Always hooked up his linkages by the book. Never reversed his ailerons.

[ColtPilot]

Reads like an obituary. He was a wonderful man. Always hooked up his linkages by the book. Never reversed his ailerons.

Very true and much alive. Don't downplay a veteran.

[janmb]

Just because a design deficiency doesn't show up on the first, 10th or 100th flight doesn't mean it's not lurking there waiting for just the right combination of circumstances to trigger it.

Precisely.

The all too common line of arguments like "I have this or that many flights without issue" is simply a classic demonstration of the fact that the vast majority of human beings on this planet have a real hard time with the concept of statistical significance. Or most importantly the lack thereof.

It is basic human nature to think what we observe is more significant to calling trends or conclusions that it ever is. Absolutely everyone does it, unless consciously exercising awareness not to.

[Evan D]

Thanks for your service and retirement is awesome. From a retired sailor,

[janmb]

Very true and much alive. Don't downplay a veteran.

Sorry mate, but the veteran card don't get much credit in my book. (as in veteran within the hobby)

This is in general and NOT about you in specific, but my view is that experience only really ever matters if people also possess the practical and theoretical subject matter skills necessary to actually make correct sense of what they observe. Without it, experience is just another word for wrong teachings.

[Elbee]

Hey Guys, please. If you want to talk methodologies or the lack there of, may I suggest the "Lounge Forum". Respectfully, LB

[mshagg]

Obviously FW/ Motion think that stronger stab servos were the cure

I think they were probably onto something as well. I carved out space and put some standard sized servos in there - you dont appreciate how mushy the pitch response is, even with top of the line mini sized servos in there, until you pull back on the stick with 10kg-cm running the show. It's a different jet.

Besides trying to intentionally destroy it with full flaps at high speed (we've all seen the footage of the tail bending like rubber) I've reached a degree of comfort when pulling out of dives etc. I still submit that the degree of flex isnt 'normal' (what other PNP lawn darts with an inappropriate flap/speed condition?) but it's manageable. That and I've logged enough hours with it now that, if it does go in, it'll be a c'est la vie kind of thing.

[janmb]

I think they were probably onto something as well. I carved out space and put some standard sized servos in there - you dont appreciate how mushy the pitch response is, even with top of the line mini sized servos in there, until you pull back on the stick with 10kg-cm running the show. It's a different jet.

Besides trying to intentionally destroy it with full flaps at high speed (we've all seen the footage of the tail bending like rubber) I've reached a degree of comfort when pulling out of dives etc. I still submit that the degree of flex isnt 'normal' (what other PNP lawn darts with an inappropriate flap/speed condition?) but it's manageable. That and I've logged enough hours with it now that, if it does go in, it'll be a c'est la vie kind of thing.

Completely agreed.

Those claiming the elevator response with mini servos is crisp and good simply haven't tried what precise stick response really is. I'm running upgraded rods and servos (beefy minis), and that is still fairly mushy.

Standard servos simply makes sense on an application like this one. Even more so when flying nose heavy.

And yes, the relatively soft elevator and fuselage sections will probably still leave some mushiness regardless of servos and rods, unless further stiffening mods are applied.

When I get around to rebuilding my MiG with vectoring, I intend to:

160 Pro Modeller servos, moved outboard, 2S lipo voltage
4-40 rods or better
glass the elevator surfaces and fuselage sections
Wingtip washout mod
Slight reflex for both flaps and ailerons
Crow mix with flap deployment
Vectoring with as much deflection as physically available
CG 20ish aft of marks

[mshagg]

Honestly I'd just put a proper sized servo in there. The modification isnt exactly radical (see photo). I've carved more foam from a 3S warbird. Similar torque without running at the ragged edge of what the servo can handle and powered from the BEC like a normal plane should be. Beefy servo horn included. And almost half the price of a botique mini...

[janmb]

Honestly I'd just put a proper sized servo in there. The modification isnt exactly radical (see photo). I've carved more foam from a 3S warbird. Similar torque without running at the ragged edge of what the servo can handle and powered from the BEC like a normal plane should be. Beefy servo horn included. And almost half the price of a botique mini...

I already have a set of 160 so will be using those. 11.5 kg/cm @ 8.4

[Pizza Guy]

Looking for all the recommendation on upgrades for the Mig-29 to make it more reliable. New to the sport. I have been flying the Habu STS and the A10 with twi 64mm EDF so I'm jumping in and probably over my head but what heck

Pizza Guy
Tom Stark from Wisconsin

[Elbee]

Looking for all the recommendation on upgrades for the Mig-29 to make it more reliable. New to the sport. I have been flying the Habu STS and the A10 with twi 64mm EDF so I'm jumping in and probably over my head but what heck

Pizza Guy
Tom Stark from Wisconsin

Hey Tom, Welcome to 'The Squawk', Sir. No you are not over your head, the MiG is large airframe. My first venture back to R/C flying was the big Freewing A-10 and it is a '*****-cat'. Glad you are onboard. Best, LB

[mshagg]

Looking for all the recommendation on upgrades for the Mig-29 to make it more reliable. New to the sport. I have been flying the Habu STS and the A10 with twi 64mm EDF so I'm jumping in and probably over my head but what heck

Pizza Guy
Tom Stark from Wisconsin

Lol you've made quite the splash into the hobby there tom.

For flying circuits it's good out of the box.

It's a lot of plane though man, and needs a lot more building than the eflite bind and fly models. You also need to be confident setting up the reciver/electronics.

Have you considered something like an Avanti or F22? Even the latter might be a bit much for a third plane. But they're far simpler, much lighter and equally as good fun to fly (maybe even better).

But yeah, if you're determined to tackle this one just make sure it has the upgraded servos and it's a robust bit of kit. Don't fly fast with the flaps down!

[themudduck]

Very true and much alive. Don't downplay a veteran.

Hey CP, some fun reactions to your post huh. As Elbee said, . Well, I have participated in this discussion, which has been going on for thousands of posts. There have been so many goofy ideas put forward but the group has come up with what are probably some very useful modifications that could help, and won't hurt, namely: stronger elevator linkage (HD 4-40) to replace the originals, installing longer screws on the elevator horns and gluing them in, securing the attachment setscrews for the elevators so they can't fall out, adding some weight to aerodynamically balance the elevators, using the inner hole on the elevator servo arm, replacing the original FW servos with higher-torque FW servos (FW sent replacements to us early guys, and all the newer kits have the newer servos), installing chokes to reduce the possibility of radio interference, balancing the model about 10-15mm back from the recommended point (to take strain off the elevators), adding a tiny bit of reflex to the flaps and ailerons (to reduce the amount of up elevator trim needed) - and there are even a few more. Many of these things are simply common sense. I did all of those things.... and of course I DON'T fly with the flaps down at high speed (that's just stupid). But even after all this, I still had a butt-puckering incident where the elevators simply stopped working completely while the plane was flying straight at medium speed - suddenly no elevator control at all, I could not pull out.... I chopped the throttle before impact and then just as suddenly elevator control returned and I was able to have a happy ending. Then I went home and changed my pants~! So in spite of all of those mods, it still happened. I am still waiting for an explanation. My best guess is that digital servos will stop working if the voltage coming from the receiver drops. I don't know if anyone's done an analysis on the stock BEC to see if it could possibly overload or overheat and fail to supply enough amperage under certain conditions, and for just a few seconds.... but my guess it that something like this might be going on. I don't know. Why would only the elevator servos stop, both at the same time? (and yes I bypassed the blue box for the elevators)

[mshagg]

Why would only the elevator servos stop, both at the same time? (and yes I bypassed the blue box for the elevators)

Voltage drop over the long wire run? There was some analysis of voltage at the servo which was a little concerning. One of the discussed mods was installing lower gauge servo extensions. A little more headroom in the BEC probably also goes a long way..

[ColtPilot]

Hey CP, some fun reactions to your post huh. As Elbee said, . Well, I have participated in this discussion, which has been going on for thousands of posts. There have been so many goofy ideas put forward but the group has come up with what are probably some very useful modifications that could help, and won't hurt, namely: stronger elevator linkage (HD 4-40) to replace the originals, installing longer screws on the elevator horns and gluing them in, securing the attachment setscrews for the elevators so they can't fall out, adding some weight to aerodynamically balance the elevators, using the inner hole on the elevator servo arm, replacing the original FW servos with higher-torque FW servos (FW sent replacements to us early guys, and all the newer kits have the newer servos), installing chokes to reduce the possibility of radio interference, balancing the model about 10-15mm back from the recommended point (to take strain off the elevators), adding a tiny bit of reflex to the flaps and ailerons (to reduce the amount of up elevator trim needed) - and there are even a few more. Many of these things are simply common sense. I did all of those things.... and of course I DON'T fly with the flaps down at high speed (that's just stupid). But even after all this, I still had a butt-puckering incident where the elevators simply stopped working completely while the plane was flying straight at medium speed - suddenly no elevator control at all, I could not pull out.... I chopped the throttle before impact and then just as suddenly elevator control returned and I was able to have a happy ending. Then I went home and changed my pants~! So in spite of all of those mods, it still happened. I am still waiting for an explanation. My best guess is that digital servos will stop working if the voltage coming from the receiver drops. I don't know if anyone's done an analysis on the stock BEC to see if it could possibly overload or overheat and fail to supply enough amperage under certain conditions, and for just a few seconds.... but my guess it that something like this might be going on. I don't know. Why would only the elevator servos stop, both at the same time? (and yes I bypassed the blue box for the elevators)

I personally moved every flight control, dropped the landing gear, flaps, and full throttle at the same time on my teststand without a brown out or anything to stop working. I don't have a device to check amp draw. D85MG servos installed as I did notice the original servos would stall out with very little finger pressure applied. I've put my MIG through this process 6 times with pressure on the flight controls. No issues noted. Just waiting for spring to get back in the air. In the meantime another turbine jet on the bench. Lets go fly and have fun. I was thinking of balancing the elevators, but way to much weight would be required for that to be effective. Hence a very tail heavy aircraft. See ya at the field.

[kallend]

adding some weight to aerodynamically balance the elevators,

Statically balancing the FFS with weights is not going to do anything about the real issue there, which is that the pivot axis is way far ahead of the center of pressure.

[ColtPilot]

Statically balancing the FFS with weights is not going to do anything about the real issue there, which is that the pivot axis is way far ahead of the center of pressure.

Already knew that, just testing a theory to see if static balance could be achieved. As I stated, would require to much weight as the pivot point is to far forward. The MIG flies well and I like it.