I have a question regarding setting up program mixes for the Sukhoi. Trying a flat turn needs some up elevator mixed in. 10% helped a little, but the plane wants to dive when with a fair about of rudder. On knife edges it wants to pull to the landing gear quite a bit. Inverted, the plane needs just a touch of down elevator for level flight. So, for those of you who have the plane set up the way you want, how much up elevator did you need to mix in with the rudder?

What I do is I use a battery pack with a heavy duty output that goes to the receiver switch, then the pack has another lead that is normally used for charging. It has a standard servo connector so it will connect in to any normal switch to power an ignition. This way I can also charge through the ignition switch, the signal wire has the balance lead.

TF

Darkwarder,

I'm not sure if the wolverine switch will work for you the way you want to use it. Its really meant to be used with two seprate batteries to power your receiver and servos, as it has a monitoring system in it that will draw from the stronger of the two batteries to keep the voltage even. I'm thinking that you might have a problem with that. That being said, I am still a big believer in dual or redundant battery pack. Three weeks ago my good friend lost his scratch built skybolt because his one and only battery failed in flight. For the little weight gain and extra expense its not worth it to me.

Jim

guys quick question is the fuselage has a holes to route the pull pull wires to the back? If does I can find the if not can somebody send some pick to see where I have to opened please.


Thanks

There are slots under the covering. They are about 2 inches below the elevator servo holes.

Chuck,

Flat turns typically require a combination of up elevator and aileron opposite to the rudder to compensate for the tremendous drag increase the deflected rudder causes. The amount of elevator varies according to the amount of rudder used. As the rudder deflection increases drag the roll coupling effect generally increases much more than you would think it should. The Sukhoi has a very powerful rudder so small increases in deflection have a very large effect on drag and roll. In essence, you can reach a point where it can require full elevator deflection to compensate for the rudder induced drag. A highly deflected rudder acts just like the brakes on a car in that situation and it takes a combination of several functions to over come the brake. Throttle, elevator, and aileron in this case. When you approach that point the plane becomes extremely sensitive to any changes in attitude and airspeed since the plane is riding the edge of a cross control stall and snap condition. So basically you can only use so much rudder before a mix will no longer have enough offset to compensate. You have to hand fly some things.

The small amount of down elevator required for inverted flight sounds like you're c/g is close to where it should be. If you have one of the planes that has the two position main wing I'm curious if it's forward or aft positioned. If it's aft I would expect more tuck to the gear in KE, but that tuck is normal to one degree or another in many planes. An elevator to rudder mix of about 8 to 10% usually is plenty to take care of this.

Something that's kind of important is that few mixes handle 100% of a condition 100% of the time. Mixes typically reduce the amount of work the flyer has to do, not eliminte that work. You still have to input corrections for different things even with a mix programmed to offset the majority of a given condition. Hope that didn't sound too strange. Basically the plane can't always fly itself once positioned. It needs your input all the time to do it right.

Hey pat roy
Got a bit lost after "Flat turns" but read it 3 or 4 times and was on to it. great explanation thankyou
Lee

Pat,

Thanks for the excellent explanation. I was hoping you would speak up.

Chuck

I read it again this morning and got lost myself It was late and I'm in the middle of a house remodel[:@] so it was done in more of a hurry than it should of been.

I cleaned it up to make for better reading and comprehension. My apologies.

Hey guys I been triying to decide about batteries for my sukhoi and i really need you 2 cents I check TBM and read every thing about batteries and I a little confused. They actually talken about all the batteries on the market except for ni cads but everything else from NiMh to the new A123. They even have a chart with all the good and bad things fron all of them. Which is the really diference for all this batteries packs A123 and NiHm are almost the same weigth and do not need a regulator and the other 2 which is Li Poly and Li Ion the weigth is less but they have some issues.
But they say that NiHm and A123 Don't have that many diference betwen both so please let me heard about you througths about this.


Thanks

Well, I went to to A123 and will nt be going back.

A123 is the way to go. I'm using two 23oo mh A123's, but a lot of guys are using just one.

Jim

I've been using the lithium ions since they became available, like them very much, and haven't experienced problems and don't know about any "issues". They do require a regulator though. That presents a small weight and wiring thing that some people don't like or want to deal with.

Nimh or A123? I suppose that depends on what radio you have. 2.4 you might want to seriously consider the A123. They hold a higher voltage longer and can be fast charged at the field. If a 2.4 gig radio drops to a low enough voltage you have big problems. Don't telll anyone but the same thing happens with any other type of radio so there's no excuse for not paying attention to battery levels.

You really can't fast charge a nimh. You can fast charge a nicad if you have the better cells. If you have a 72mhz radio then the nimh might be more to your liking. You probably won't fly enough flights in the normal day to run them down to the level they need re-charged if you have 2,400 mAh or greater. If you have a 72mhz 9303 tx with the standard battery you might want to think about a 2,500 mAh nimh replacement pack for it. The standard 600mAh tx battery isn't worth a crap for a serious day of flying unless you have a field charger.

Rather than go to TBM about batteries, why not talk directly to Tom? He's done a lot of research on what works best in different situations and has a solid handle on what works best in his planes with different radios and servos. He sells just about all of them set up and ready to go.

Hey guys, I'm at work and don't have the time available to review all the posts...can someone post the CG as a distance in inches from the LE at the root for IMAAC style flying? I don't do 3D yet. Thanks! Maiden tomorrow!

I'm going to write a completre explanation about batteries for powering the control system in R/C planes, I promise I will.

But for now, let me summarize; Be aware that C stands for the capacity of the battery cells in milliamp-hours. 2C means 2 times capacity, 2/c means capacity divided by two.

NiCad; 4c to 10 c current capacity depends heavily on type of cell, some self discharge, 6.5-6.7 volts, reliable but very heavy.
Nimh; 2c current supply, some self discharge, 6.6-6.7 volts fully charged, reliable but heavy for the capacity.
Li-Ion; 2c-3c output, no self discharge, 8.4 volts charged requires regulator, light with rugged case
Li-Poly; 10c-20c output, no self discharge, 8.4 volts charged requires regulator, very light, easily damaged
LiFe (A123) up to 30C output, no self discharge, 7.2 volts drops quickly to 6.6, lighter than Nimh, rugged case, very safe

A123s have the best combination of properties for R/C to give you a dependable simple power source.

TF

Thanks all of you for all the sugestions I read and take in cosideration every single point that you make.

Tom did you have a charger for those A123 ? and how you chequed those batteries at the field ? also the is a quick charger for the field ? By the way I am converter my Futaba 9C to a 2.4 system I really don't like the spectrum radio and I believe the is a waste of money when i just buy the Futaba by 2 years ago. Thats on response to Pat since he asked if i was used a 2.4 system

Thanks.

Tom.
Thanks for the battery news, this really confuses me but your explanation clears it up a bit. Do the A123 need a regulator. Iam running 2 x 1700mah nicads and they seem to help with the C/G and they are up front of the wing tube, so why is the lighter batterys better??, is it they can just put out better power for longer, could you please just expand on this a bit more. I think 2 x batterys is safe, do you think I should go to a larger capacity??
Regards in advance
Lee

The pluses of the A123, as I see it is:

1) No need for a regulator.
2) Fewer cells than Nicad or NiMh. The more cells, the more potential weak links.
3) More durable than LiPo's.
4) Safer than lipo's or any other battery technology I know of.
5) Can be charged in 15 minutes, without fear of a battery meltdown.
6) Capable of handling very high burst currents.
7) Hmmm! What else am I missing?

Lighter batteries simply make the plane lighter.

TF

Ta again Chaps, Oh well more money, I shall look into these batterys, I notice my new SWALLOW charger will charge LiFe, what does LiFe stand for?????
Thanks again
Lee.
Ps last thing I would like to do is crash this plane, its a beauty Tom.

LiFe is the generic term for A123 batteries. I think the difference between the LiPo/LiIon charging and A123 charging is the cut-off voltage for the charger.

Can you take a photo of and post a picture of your Swallow charger? I have the older V2 version of the charger and I would like to keep an eye out for the new version, this has been one of the major stumbling blocks that has prevented me from buying A123 batteries.

Cheers
Pupmeister

Pupmeister.
Howdy, the swallow charger I bought does not look any different to the other one I had, just that when I turned it on and scrolled through the battery types it came up with LiFe, so to all intents and purposes the packet will look the same, Iam at work when I write this ( self employed) but will see if there are any features that identify the type of charger version. Who sells A123 batterys here in Australia can you help?
Lee

The availability of A123 in Australia has been the second major stumbling block, however after seeing another guy at my field experimenting with packs that he had imported from the USA I decided that even with the expense, it would worth the extra cost to import them for use in my next project. However I have seen that Fromeco has just released both original and generic A123 packs so Howie at DA should have them soon. Also the same friend who imported the packs tells me that DeWalt are about to launch their A123 cordless system in Australia and a lot of people are stripping down these battery packs to make home made RX and ignition packs. There are a lot of build threads here on RCU and on F l y i n g G i a n t s on how to build these home made packs.

Just to add, if I was you and I was having no problems with my NiCd packs (and not running Spektrum/JR 2.4GHz) I would not bother changing them out with A123 packs (or any other type of batteries such as LiIon/LiPo), the weight savings of a few grams is not worth the expense IMHO. When you have to replace them or you are starting on your next Giant Scale project then I would consider the A123 packs. (I assume that you are using 6V packs)

Cheers
Pupmeister

Thanks Pupmeister
Yes iam running 2 x 6v nicads and I have the extreme link 2.4 ghz set up in my radio, IS there a problem with nicads and 2.4. so far I don't seem to have any worries[:-]. I have 2 x 1700mah supplied by Howie.
Lee

From everything I have read your system should be fine as far as power is concerned. I do not want to get into a debate on the pros and cons of various 2.4GHz systems or the 2.4 vs 72/36/35 MHz in this thread, as every time it is started, the thread just seems to degrade into the abyss and this thread has been one of the best and longest build threads for any ARF that I have been able to find on the internet and I want to keep it that way. If you want further info on 2.4GHz systems you can find lots of info on the net or PM me and I will discuss it offline.

Cheers
Pupmeister

PS I have the new JR DSX9 with a JR921 2.4GHz receiver in mine and I love it

Yeah I agree pupmiester, this has so far been a very helpful thread, specially if your in my isolated shoes. Must admit Iam very happy with my JR 9x v2 radio with the 2.4 and it flys all my planes ok.
I feel better now
Lee