c.g. balancing 1400mm corsair

[boomer108]

For you guys adding weight to the tail, can you post some pictures of how you did it and where you located the weight?

I don't have a picture but, I use Great Planes self adhesive weights and place them by the tail wheel next to the gear doors right below the horizontal tail right where they should be. I also painted them with matching paint,you can hardly see them.

[wrongroad]

G'day Roy,
I had originally balanced my V3 at the 110 mark [as per the early manuals] and found, that while it flew nicely enough, it was snappy in direction change. A sign of being tail heavy. I actually flew it like this for a few flights and used the end point adjustments to try and tame the snap.
After a while I put some thought into it [and read a bit of advice online] and decided to move the CG forward and found that I suddenly had a very nice model to fly that could perform the nice big open loops that I was looking for.
I can advise you to always use the factory nominated point as a starting point on any model and have a little play around to get the machine to fly how you like it. Who cares if the next guy hates your set up.....it will stop him from asking for a fly:p
Only move the mark by five millimetres at a time and only alter one thing at a time. If you make two changes at once, one might very well cancel the other out and you are left thinking that neither change worked.
My former instructor always wants to fly my Mustangs and I give in and let him have some time on the sticks and he absolutely hates my set up......but he still likes to fly the Ponies. It does keep the rest away:cool:

Hope I have been of assistance to you.
Regards and respect
Daryl

PS some easy ways to tell a V2 from a V3
No flaps on a V2
Long battery hatch on a V3
Plastic cowl on a V3 held in place by screws
Tail hook assembly on a V3 [sadly non working]
Weapons add on pack on a V3 [leave off when flying]
Oil cooler 'chin' on the bottom of the cowl on a V3
4 blade prop as standard on a V3, option of a three or four blade on the V2 [supplied with two hubs, at least mine was:D]

[AkumaZeto]

with the v3 it is impossible to get a decent cg unless you take battery out of the pocket in nose. I hate this setup :(

[OV10]

with the v3 it is impossible to get a decent cg unless you take battery out of the pocket in nose. I hate this setup :(

AZ - I had the exact same feelings about the v3 until I decided that I had enough and did a battery relocation mod. After a lot of interaction with other contributors on this thread since 5/2015, last fall the mod got done and cured my CG/flight ailments. Jan of this year on post #35 I shared pics of that mod. The tray/rail assembly that I used is from the FMS P-51D https://www.motionrc.com/products/fm...d-battery-tray

[boomer108]

G'day Roy,
I had originally balanced my V3 at the 110 mark [as per the early manuals] and found, that while it flew nicely enough, it was snappy in direction change. A sign of being tail heavy. I actually flew it like this for a few flights and used the end point adjustments to try and tame the snap.
After a while I put some thought into it [and read a bit of advice online] and decided to move the CG forward and found that I suddenly had a very nice model to fly that could perform the nice big open loops that I was looking for.
I can advise you to always use the factory nominated point as a starting point on any model and have a little play around to get the machine to fly how you like it. Who cares if the next guy hates your set up.....it will stop him from asking for a fly:p
Only move the mark by five millimetres at a time and only alter one thing at a time. If you make two changes at once, one might very well cancel the other out and you are left thinking that neither change worked.
My former instructor always wants to fly my Mustangs and I give in and let him have some time on the sticks and he absolutely hates my set up......but he still likes to fly the Ponies. It does keep the rest away:cool:

Hope I have been of assistance to you.
Regards and respect
Daryl

PS some easy ways to tell a V2 from a V3
No flaps on a V2
Long battery hatch on a V3
Plastic cowl on a V3 held in place by screws
Tail hook assembly on a V3 [sadly non working]
Weapons add on pack on a V3 [leave off when flying]
Oil cooler 'chin' on the bottom of the cowl on a V3
4 blade prop as standard on a V3, option of a three or four blade on the V2 [supplied with two hubs, at least mine was:D]

Hey WrongRoad!

Thanks for the info. I experienced the same thing yesterday with my V3. It was sguirley and hard to handle. So I removed the weight in the tail put the plane on the balancer at 95mm from the leading edge and walla! Perfect. I going out again Saturday and I'll see how she flies. Thanks again :D

[wrongroad]

G'day Roy,
My good deed for the day is taken care of:D
It is a pleasure to be of assistance if only a little bit.
One more thing, do not worry about landing with full flap, the model simply does need it and full flap can make the model hard to handle near the ground as full flap is not producing any lift but is producing drag only, therefore you need a lot of power to maintain sufficient airspeed for control. This could be costly if you need to go around...want to know how I know this?:rolleyes:
With all the frontal area of the Corsair with the wheels down, there is already a lot of drag being produced by those bits hanging in the breeze. If you want to know what is there, look at the model head on with the gear down and then drop full flaps.
I hope you have a great set of flights with her on Saturday.
Regards and respect
Daryl

[AkumaZeto]

I find the corsair the easiest of all my birds to land. Settles in nicely and just sticks.

[boomer108]

Well everyone Warbird,Az,and WrongRoad. I think we can agree that 110mm from the L.E. is probably wrong for the V-3. I appreciate all your input and see that we found two different approaches to solving the problem ie. take the battery out of the pocket and move it into the cockpit area with tray, or move the balance point to 95mm from the L.E which I believe is closer to the main wing spar anyhow. So same effect different approaches take your choice in which you care to use. Thanks again gentlemen and good flying. I'll let you know it flys.

Roy B.

[AkumaZeto]

It will fly great. Dont let it get airborne though before its ready or it will be mush city. I love mine. Handles win nice too. The only thing I would suggest is run a few rods down through the nose into the fuse. If you watch how much the front area flexes it will make you cringe.

[wrongroad]

G'day Roy,
AZ has some good advice there about keeping the F4U on the ground until the aircraft reaches flying speed.
The trick is to get the tail up into the flying position as quickly as you can and then 'fly' her on the ground until she either lifts off on her own or you judge flying speed has been reached.
If you keep the tail down, the high AoA of the wing [because of the long landing gear] will lift the model into the air but purely on thrust. The wing will be in a stalled condition and then the Corsair will drop her nose, roll left and, unless you are very lucky, go cartwheeling in a spectacular crash. I know this from bitter experience.
Each different model has its own personality and the Corsair is the joker in the pack. She can be a good card or be the nail in the coffin if you go to sleep at the sticks.
However, it is a nice model to fly once the CG is sorted.
Regards and respect
Daryl

[boomer108]

Thanks Daryl!

I've never had any trouble taking off, just the nagging problem of the cg and associated handling characteristics. I hoping for a good flight Saturday. I'll let you know.

Roy B.

[boomer108]

Thanks Daryl!

I've never had any trouble taking off, just the nagging problem of the cg and associated handling characteristics. I hoping for a good flight Saturday. I'll let you know.

Roy B.

Hey Daryl!

. Well I finally got a good day to fly my Corsair. I first flew it with the battery (4s 3000man) in the cockpit area balanced at 110 from the L.E., much to snappy on the controls. Then I flew.it with the battery in the nose pocket( balanced a t 95 from the L.E.) flew great until I tip stalled it in a turn, luckily little damage it will fly again. I'm glad I sorted out the c.g. problem I just need to keep my speed up and my head out of my behind.

Roy B.

[wrongroad]

G'day Roy,
Glad to hear that it all went kind of to plan. Sad to see that you planted her though.
One thing, FMS might get a few things wrong but they do make them tough.
I put my F4U [V3] into the long grass here two years ago when a take off went wrong and there was not enough room to stop. So I goosed the throttle but could not clear the six foot high giant Parramatta grass. This is a very strong grass that will wear out blades on a slasher as quick as you can fit new ones. It treated the light weight model with utter contempt.
The result was the nose basically smashed back to the leading edge and the cowl in several pieces.
I ordered a new cowl and set about the rebuild. Six weeks later the model won best foam model [pilot's choice] and I did not use the new cowl as I was able to fix the old one.
My V2 unit was all but on the ground after a good flight here about four years ago when a willy willy [ground thermal tornado] came across the runway and picked her up about twenty feet, turned her on her back and simply dropped her on the ground.
I dusted her off and flew again half an hour later.
I can relate a funny story with the V3. I ground test all my models with at least one battery being put through before taking to the air. This particular morning, a cow came running across the paddock mooing like crazy and hell bent on doing the Corsair no good at all.
I do not know what she thought it was and it took me several attempts to get her to cease the attack. I was so out of breath after that and my heart rate was quite high from the effort and the 'bull fighter' rush.
Luckily I am not frightened of cattle or horses having worked on a stud farm and being a jockey for my first job. The kilos were not kind to me!
I have had an interest in RC flying since I first saw planes being flown in the paddock across from where I was apprenticed as a jockey.
In 1978, I was earning $12 a week [for an eighteen hour day, seven days a week] and the models were way out of my price range then.
Still, I could sit on the hill and enjoy the machines...funny, I never saw one crash and as a brash fifteen year old thought that there could not be all that much to flying a model plane........I was right, it is just the take off and landing that is the hard part. Yeah, the bit in between is not that easy either, as I did learn.
Sorry to bore you with that.:p
Regards and respect
Daryl

[Pheonix]

I am using the battery compartment with a 3600, 50C battery. I have V2 and there is a space for the ESC on this one. I changed the ESC to a hobby Wing 100A and replaced the motor with the same one that comes with the P40B. It is a good fit for the mount. I balanced mine at 110 and expected it to be nose heavy, which it was. Using the EZ lite balancer, I need about 2 oz of weight on the tail for balance. The new power plant, with the Aspire sound system is just awesome. The plane flies really well at this CG.