Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[Hugh Wiedman]

There is no agreed upon engineering definition of "C" rating, and no independently established engineering standard or test procedure for measuring it. That is why marketing departments can put any number they like on the label with no fear of being sued for false advertizing. Data like in the RCG thread are good for comparitive purposes but shouldn't be called "actual".

You pays yer money and you takes yer chance.

Very true, but you can measure a batteries individual cell internal resistance and compare those againat other batteries to at least easily guesstimate which battery has a higher discharge rate. Ultimately, the final test rest in actual use and the Spektrums fail, at least for me, in both areas. But to each his own.

[kallend]

Just had to weigh in on this. First of all, the Viper will fly with a good/bad/in-different battery, so that's not a good "test" subject. You may love your Spektrum batteries (I guess someone has to), but I can guarantee you that they rank very poorly on the 3 most important issues. They are 1) way over priced, 2) the "actual" C (NOT THE ADVERTISED C) on the 5000 100C is actually 25C
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:

There is no agreed upon engineering definition of "C" rating, and no independently established engineering standard or test procedure for measuring it. That is why marketing departments can put any number they like on the label with no fear of being sued for false advertizing. Data like in the RCG thread are good for comparitive purposes but shouldn't be called "actual".

You pays yer money and you takes yer chance.

[Hugh Wiedman]

I have to disagree with you on the Spektrum batteries, i use them in my Viper 90, around 100 flights, never any issues whatsoever. They also charge nicely with the Spektrum smart charger. Must be one of the most stable lipo batteries ive had the past 20 years.

Just had to weigh in on this. First of all, the Viper will fly with a good/bad/in-different battery, so that's not a good "test" subject. You may love your Spektrum batteries (I guess someone has to), but I can guarantee you that they rank very poorly on the 3 most important issues. They are 1) way over priced, 2) the "actual" C (NOT THE ADVERTISED C) on the 5000 100C is actually 25C and on the 7000 30C is actually 16C and 3) heavier than comparable batteries. Most everyone in this forum knows I spent a lot of time and money testing 6S batteries (including doing some testing for MRC and the Admirals), and Spektrum is near the bottom of the list. You can also go to RCGroups and there is a complete testing of many batteries and see for yourself. Or, do what I did, Buy a Progressive IR meter (tests actual C, individual cell amps and individual cell resistance) and a Power meter and hook it up to your aircraft.

I can also guarantee you that if you get the Mig and fly it on 2 Spektrum 7000's, you will immediately say the "MIG IS A PIG"!! And it will be on those packs. Several of us fly our Migs on the SMC 5300 40C (Actual tested C of 39 and weight of 684 gr) or the SMC 6200 40 C (actual tested C of 38-39 and weight of 814 gr). Flies like a dream on the 5300's and even the 6200's. Unfortunately, SMC is in the process of redesigning all their packs because of the lithium shortage/price, but soon they'll be back in inventory. Liperiors were also good for actual C, but weighed a bit more. If you're not in the US, others like xviper (listen to him, he knows) have found the China Hobby batteries are good and lately the Codder HV sound great. But don't waste your money on the Mig if you plan on using Spektrum batteries.

Especially with EDF's, the inrunners THRIVE on a higher discharge rate packs, more so than the outrunners (but they still get a boost). With the Mig stock fans, the Spektrums will draw about 89 amps and 2061 watts. With a decent high C battery like SMC/ Liperior/China Hobby/ Codder HV more like 103 amps and 2420 watts and about 10-15% MORE THRUST than with the Spektrums. The 2 Migs at our field both have the FMS 2100 12 blade and static on the bench with the SMC's are at 125 amps 2895 watts, another 15-20% over the stock fans, but you don't need the FMS fans, the stock fans are great with the TV nozzles. We use the FMS fans because we're flying off grass and just can't leave well enough alone!

Don't take my word for it, get the testing meters and see for yourself and look up the studies people have already done. Don't throw the 10's of thousands of dollars away on crappy batteries like I have!! This will save you a ton of money. And if you still get the Mig and use Spektrums, keep my number and I'll buy it off you at a healthy discount when you decide it's "Not Worth The Money"! I may even spring for shipping!

[Evan D]

Oh, the ones with the batteries and linkages in the wrong spots and not lowering the flaps at speed, got it.

Yep...just like I saw in all those early videos.

[radfordc]

What you have done is simply to say that there are other ways to crash your airplane and one is to deploy your flaps at speed.

Yep...just like I saw in all those early videos.

[Evan D]

Thanks.

Make all the "suppositions" you want....

Doesn't take away from my opinion that the first rash of crashes were because of poor battery placement and not following the instructions when assembling the elevator linkage OR that there was an issue with alpha lock.

What you have done is simply to say that there are other ways to crash your airplane and one is to deploy your flaps at speed.

[radfordc]

Early on there were a few videos with crashes. Most looked like they could not pull out of dives and they showed the people using heavy batteries in the forward and aft battery spots. The TV units were not out at that point and there was no way those planes were balanced even to the manuals slightly nose heavy recommendation. To me it looked like the people didn't read the manual and didn't know there was a third, the center, spot to place a battery. It also looked like they put the servo linkage into the outer hole of the servo arm causing the elevator servos to work harder. My opinion is they caused the crashed themselves. When I built mine with the original servos I had no issues flying it.

I've told my story here before but I guess one more time is needed!

My 6000mah batteries were located in the center and aft location. I added additional lead weight to the tail to bring the CG 10mm aft of the recommended location in the manual. The servos were the replacement ones provided by MRC after crashes started happening and the linkages were correct.

I had flown a normal flight and was ready to land. I turned onto the downwind leg and hit the gear switch and without thinking also hit the flap down switch. The jet immediately pitched 45 degrees nose down and I could not recover with full up elevator.

Make all the "suppositions" you want....

On my second plane I am very careful to get the gear down and the plane slowed before lowering the flaps and haven't had any problems....yet.

[Evan D]

I assume you saw my answer. There are three battery areas on this plane to help balance it with or without the tail weight added when adding the TVs. Without TV you'll need to use the rear and middle spots and because the 7000 is wide you may have to remove some foam under the canopy. If you install the TVs you'll be right on the edge of rear and forward or rear and center. If you balance it on the marks you will want rear and forward. If you balance it aft of the marks, as many on here do, you'll be in that no man's land of R&F being too far forward and R&C being too far aft. But it's workable.

Strong enough is something you'll have to decide for yourself.

[gr8pics]

I think I'll bow out of the Spektrum battery thing after this post. If you are happy with what you get for what you pay, then so be it. I have the Viper 90 as do several others where I fly. The Viper 90 is a very versatile jet and can fly anywhere from "OK" to spectacular. If you have nothing else to compare it to, then this ranking has no meaning. Our Vipers can perform very nicely on low performing batteries to outstanding on top tier batteries. You will never know or see the difference if you haven't tested it. Put in a ChinaHobbyLine 65C (35 - 40C real world load test) or an SMC 40C (real world 38C) and you may see that your "never any issues whatsoever" was only mediocre to "I had no idea", buy hey, not knowing can be bliss. Horizon Hobby loves "blissfully not knowing". They are ecstatic that all their marketing did what they wanted it to do - selling low/mid tier products for over-the-top tier prices.
As scientists say ........................ "QED".

I was just asking, if they can be used, if they fit, and are strong enough for this model, without any ripping, as i already got 4 of them. Im not worried about the quality itself

[xviper]

I think I'll bow out of the Spektrum battery thing after this post. If you are happy with what you get for what you pay, then so be it. I have the Viper 90 as do several others where I fly. The Viper 90 is a very versatile jet and can fly anywhere from "OK" to spectacular. If you have nothing else to compare it to, then this ranking has no meaning. Our Vipers can perform very nicely on low performing batteries to outstanding on top tier batteries. You will never know or see the difference if you haven't tested it. Put in a ChinaHobbyLine 65C (35 - 40C real world load test) or an SMC 40C (real world 38C) and you may see that your "never any issues whatsoever" was only mediocre to "I had no idea", buy hey, not knowing can be bliss. Horizon Hobby loves "blissfully not knowing". They are ecstatic that all their marketing did what they wanted it to do - selling low/mid tier products for over-the-top tier prices.
As scientists say ........................ "QED".

[Evan D]

Are you disagreeing on value, suitability, performance???? Are you talking about the 7000 30C?

I don't have any of the 7000 30C, in fact I don't have a single Spek or smart battery. But how can you consider a battery that cost $190 (plus tax) each a value? I have a dozen of these and love them, $72ea, no tax, free shipping.

Amazon.com: Socokin 6S Lipo Battery Soft Case 6000mAh 22.2V 60C with EC5 Plug for RC Model Racing Car RC Car Truck Boat RC Quadcopter Airplane Drone Helicopter : Toys & Games

And, as I mentioned, you have to be within the Spektrum Smart eco system to get any advantage with them.

I have to disagree with you on the Spektrum batteries, i use them in my Viper 90, around 100 flights, never any issues whatsoever. They also charge nicely with the Spektrum smart charger. Must be one of the most stable lipo batteries ive had the past 20 years.

[HangarQueen]

I have to disagree with you on the Spektrum batteries, i use them in my Viper 90, around 100 flights, never any issues whatsoever. They also charge nicely with the Spektrum smart charger. Must be one of the most stable lipo batteries ive had the past 20 years.

You might be okay with them, but the fact remains is that they for instance those advertised as 100C, but in reality closer to 25C, relatively heavy for a 25C battery, and overpriced in comparison with other better performing batteries. I would never buy them, as there are much cheaper, lighter and better performing batteries available.

[gr8pics]

You spoke of "value" and "worth it" earlier. This is a prime example of this concept. Read Evan's comments of the real world load tested C-rating for these batteries. Personally, I wouldn't touch these things with a barge poll, especially for a high draw system like an EDF. There's a couple of guys at my field who have some Spektrum batteries and they use them on their less draw prop planes. The "smartness" isn't really of any use after the initial "discovery" period. They work "OK" for the prop planes but when they put them into their small, lower performance EDFs, they are very disappointing.

I have to disagree with you on the Spektrum batteries, i use them in my Viper 90, around 100 flights, never any issues whatsoever. They also charge nicely with the Spektrum smart charger. Must be one of the most stable lipo batteries ive had the past 20 years.

[xviper]

About batteries, do you know if it can take the Spektrum 6s 7000 packs?
I actually like to fly more scale just cruising around in slower movements, not flipping it around like a coin, but sometimes its nice to have the ability to rip it. with that kind flying, i should be able to get 5-6 mins on 6000, or?

You spoke of "value" and "worth it" earlier. This is a prime example of this concept. Read Evan's comments of the real world load tested C-rating for these batteries. Personally, I wouldn't touch these things with a barge poll, especially for a high draw system like an EDF. There's a couple of guys at my field who have some Spektrum batteries and they use them on their less draw prop planes. The "smartness" isn't really of any use after the initial "discovery" period. They work "OK" for the prop planes but when they put them into their small, lower performance EDFs, they are very disappointing.

[Evan D]

Early on there were a few videos with crashes. Most looked like they could not pull out of dives and they showed the people using heavy batteries in the forward and aft battery spots. The TV units were not out at that point and there was no way those planes were balanced even to the manuals slightly nose heavy recommendation. To me it looked like the people didn't read the manual and didn't know there was a third, the center, spot to place a battery. It also looked like they put the servo linkage into the outer hole of the servo arm causing the elevator servos to work harder. My opinion is they caused the crashed themselves. When I built mine with the original servos I had no issues flying it.


Later Motion sent out new, slightly higher torque, elevator servos to people that had bought the first kits and put these servos in kits they sent out (they just put them in the box, not installed in the plane). Still later on FreeWing started putting in even higher torque servos and upgraded linkage on the planes.

There was a lot of discussion about the crashes and possible fixes here in the forums. I won't go into all of the opinions, it's an interesting read. At the end of the day higher torque servos and better linkage has seemed to stop the reported crashes.

Maybe separate (you'll have various opinions on this too) is the "alpha lock" issue where it gets into high alpha and you can't get it out. Throttle makes it worse. When the TVs came out and people installed them they do help get you out of alpha lock.

My opinion is the two issues are not related. My opinion is that if you have TVs there is no crashing bad habit. My opinion is that the big Mig does handle a bit odd, like it's on the edge pitch wise. Because of this I do my antics higher than with other planes. Does it make buying one a bad decision? That's a decision you'll have to make.

Does this one have a bad habbit of crashing?

[Evan D]

When I said in my opinion best to fly off paved runway it was more about how some have noted that the main gear area foam gets soft and the gear develops a toe out warp. And I did say my opinion...

While I have flown with 6000 I settled on 5200 50C 645g batteries I use in many aircraft. They balance the plane well and give me 5:30 of flight time. About the Spektrum 7000 30C G2. First I will never buy a Spektrum battery, I think there are many other batteries that are better quality. Second it's only 30C. Third its "smart" and unless you stay in that ecosystem (smart chargers) it doesn't make sense. But, they are 720g and that will balance well as long as you have the TVs. They are a bit wide and if you need to use the center battery space you may need to cut a little foam under the canopy for clearance.



Talk about not having anything to do with his question...

But a stock Sukhoi 35 will still fly rings around it, has not needed remediation to eliminate really bad habits (aka crashing) and comes complete with TV.

[kallend]

Does this one have a bad habbit of crashing?

I suggest you read the early posts in this thread, particularly those relating to why the FFS servos needed replacing, and those relating to alpha-lock.

[gr8pics]

But a stock Sukhoi 35 will still fly rings around it, has not needed remediation to eliminate really bad habits (aka crashing) and comes complete with TV.

Does this one have a bad habbit of crashing?

[gr8pics]

100% agree with Evan D that it is worth the money assuming you add TV nozzles and have a good "real" high C battery packs. It's impressive in the air as well as on the ground. The only thing I may disagree on is that it will fly off of grass with little to no problems. Both RudyD54 and I fly off grass and even before adding the TV nozzles or the upgraded FMS fans, it got off just fine and enjoyed settling in on landing on the grass with minimal roll out. Our take-off distance with the FMS fans is no longer than the majority of EDF's I have.

Yea, the wheel size looks like the same as on my Viper 90. People fly off grass with even smaller wheels that that, such as a Viper 70, unless its unplowed field with grass on top.

[gr8pics]

If you can handle or like the gracefulness of a pretty sluggish aeroplane (without thrust vectors) that needs two 6s batteries for about 3 minutes of motor time. With that nasty and costly habit of getting stuck in high alpha if you do some aerobatics.

You need a lot of batteries or the possibilty to charge at a high C-rate at the flying field.

Whats the minimum c-rate for easy crusing, and no ripping?