Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[Airguardian]

Thanks!

I guess I'd get it flatter with a more aft CG but that's not happening until I get around to installing the thrust vectoring nozzles ;)

[GliderGuy]

Thanks!

I guess I'd get it flatter with a more aft CG but that's not happening until I get around to installing the thrust vectoring nozzles ;)

was actually looking for a more nose down standard spin.

Close enough.

[kallend]

was actually looking for a more nose down standard spin.

Close enough.

That is SO mid 20th Century.

[Airguardian]

Flat flatspins are cooler than non-flat flatspins.

[Airguardian]

This weekend I attended a Jet Meeting in Barcelona (first since the pandemic started, at long last!). It was pretty windy so I flew the MiG-29 almost exclusively as I find this one deals better with wind being bigger and all, even without gyros.

Many videos on that to come soon but in the meantime... some other, new MiG flights! :)

[kallend]

This weekend I attended a Jet Meeting in Barcelona

Ah Barcelona!

https://www.youtube.com/watch?v=0kqyev46qyI&ab_channel=rymndjesus

[GliderGuy]

Since first posting this in July, I have replaced both main gear due to gear servos beginning to act weird. Worth a reposting…took almost 3 months to need it.

Did my first “adjustment” process on the “new” main gear axle pins today.

==========
The main gear axles eventually take a toe-out, bottom-out splay setting. The axle metal isn’t soft, but at least it isn’t brittle like the F-4 pin. You can tap the MiG’s axle with a hammer while the axle is secured in a vice without snapping it into two pieces. It takes several fairly hard taps with a hammer to bend the axle, but don’t overdo it.

Consider the “flat” on the inside of the axle is “down”…the outboard tip must be bent forward and down. This takes a bit of mental gymnastics to ensure you are bending each axle correctly. Note: It doesn’t take but a few degrees of a bend to get the mains back like new… sitting vertically straight with no toe-out. This is not an elegant repair technique, but it works…and has been discussed in this forum before. Place only the area of the flat into the vice jaws.

What hasn’t been discussed is how frequently the adjustment needs to be done. I reckon that depends on your landing technique and runway surface. I operate off hard surface and mostly make good landings. But I do have my share of not perfect landings. From what I have seen, the axle adjustment process isn’t needed very often. But, eventually it will be needed.

=======
This new set of mains probably has about 300 to 400 landings, so the axle pins hold up pretty well.

-GG

Post bending….results below. Nice and straight!!!

[xviper]

Since first posting this in July, I have replaced both main gear due to gear servos beginning to act weird.
-GG

What do mean "weird"? I flew mine again this morning and upon retracting the gear for the trip home, one main gear started the cycle by chattering (stuttering). About 1/2 way through the cycle, the chattering stopped and it went up without any further problem. It's like the retract is getting "tired". Perhaps a bit of light oil on the worm drive is appropriate? I do have a spare on hand should it become necessary to replace it.

[GliderGuy]

What do mean "weird"? I flew mine again this morning and upon retracting the gear for the trip home, one main gear started the cycle by chattering (stuttering). About 1/2 way through the cycle, the chattering stopped and it went up without any further problem. It's like the retract is getting "tired". Perhaps a bit of light oil on the worm drive is appropriate? I do have a spare on hand should it become necessary to replace it.

Weirdness included - Partial retract…hanging up at about 3/4 finished. This became a somewhat intermittent but more frequent happening. Good description…like the servo was getting tired. Oil/grease didn’t help long term.

Sometimes cycling at a slow airspeed would work….sometimes retracting during inverted flight would work, but what a PITA. New main servos fixed the problem 100%. No more PITA.

-GG

PS…added a photo to the prior post.

[xviper]

Weirdness included - Partial retract…hanging up at about 3/4 finished. This became a somewhat intermittent but more frequent happening. Good description…like the servo was getting tired. Oil/grease didn’t help long term.

Sometimes cycling at a slow airspeed would work….sometimes retracting during inverted flight would work, but what a PITA. New main servos fixed the problem 100%. No more PITA.

-GG

PS…added a photo to the prior post.

I had this same problem with the stock retracts on my Eflite CZ T-28. One one retract, the slightest bit of resistance on the strut while retracting made the unit stop where the resistance was applied, no matter where in the cycle it occurred. I think the retract was "tired". A new, "fresh" retract cured the problem. Considering the weight of some of these struts and the leverage they present, the retract motors on these things are puny.

[GliderGuy]

Hi Xviper…. My suggestion = change it. It’s not gonna get any better. Chattering servos never do get better!

Might save you from doing a belly landing. Changing is cheap insurance.

I’ve been flying a chattering gear door servo on the P-38 for months. Guess what? It 100% died over the weekend. Luckily…gear doors stuck open.

-GG

[xviper]

^ You're right. They don't get better.

[Skosh25]

When in doubt, swap it out!

[dabevan]

I'm just assembling my FW MiG 29 and was intending on using one 5000mAh and one 4000mAh to make a parallel pair.

...but I've noticed that the two pairs of battery leads appear to be separate from each other.

Is each lead only connected to one motor/speed controller? If so then presumably I'll need to connect both pairs of leads together in parallel, or use same capacity packs?

Thanks
David Bevan

[Evan D]

Yes, each ESC has it's own connector. I would hesitate in creating an adapter, something like a figure -H-, and go with two of the same packs.

[Airguardian]

Just use it as it is, my 2 cents.

[GliderGuy]

I'm just assembling my FW MiG 29 and was intending on using one 5000mAh and one 4000mAh to make a parallel pair.

...but I've noticed that the two pairs of battery leads appear to be separate from each other.

Is each lead only connected to one motor/speed controller? If so then presumably I'll need to connect both pairs of leads together in parallel, or use same capacity packs?

Thanks
David Bevan

Using different capacity packs will increase the possibility of drawing down the smaller capacity pack too much and potentially damaging it. I agree with AG...use the same capacity packs and keep the connections separate. Flight times for this bird are pretty good, anyway.

-GG

[dabevan]

Using different capacity packs will increase the possibility of drawing down the smaller capacity pack too much and potentially damaging it.

Thanks for the reply, but that is not how batteries work. Having two different capacity packs in parallel is absolutely fine, what you describe above is wrong.

From other answers, it sounds like the leads are not wired up in parallel meaning I either connect them in parallel and run different capacity packs or leave them as they are and run two 5000mAh packs.

Dave

[xviper]

Thanks for the reply, but that is not how batteries work. Having two different capacity packs in parallel is absolutely fine, what you describe above is wrong.

From other answers, it sounds like the leads are not wired up in parallel meaning I either connect them in parallel and run different capacity packs or leave them as they are and run two 5000mAh packs.

Dave

Do you have science or electrical facts to support your claim? If not, I don't think he's wrong and since I don't have any science to back that up, his statement holds just as much credibility as yours. In fact, I'm in agreement with GG.
Take 2 fuel tanks, 1 is 10 gallons and the 2nd one is 12 gallons. Each feeds an identical engines running at the same time at the same throttle. Which do you think will run out of fuel first? In the case of LiPo batteries, which one do you think will get to it's LVC first and possibly damage that battery? During this time, the bigger battery keeps running the first engine. True, if you gauge your flight time according to the lowest common denominator, the smaller battery, and stop flying before it can get to its danger level, then fine, neither battery gets damaged.
So please, tell us how batteries work.

[hilldebrandt]

Edit stand corrected...