Nose heavy AirCore 40 Trainer

Nose heavy AirCore 40 Trainer
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Nose heavy AirCore 40 Trainer - 10/5/2007 7:46:24 AM

Fredsterman

Posts: 98
Joined: 7/29/2005
From: Ravenna, OH, USA
Status: offline

I have an Aircore 40 trainer, that is very nose heavy. The engine is a Super Tigre .45 abc.
I have tried moving the "CG" aft. But the fuel tank is hitting the front wing dowel.

My instructor checked the CG with a full fuel tank, increased my elevator throws, and after several nose gear fixes.
He got it to fly, and gave me some control of the plane.
My first flight was ugly to say the least

He managed to land the plane, but it was a handfull even for for him

I need to add tail weights to the plane to balance it.

The question is how to secure them to the coroplast?

Post #: 1

RE: Nose heavy AirCore 40 Trainer - 10/5/2007 12:35:32 PM

DavidAgar

Posts: 2826
Joined: 12/5/2001
From: Battle Ground, WA, USA
Status: offline

You can get lead weights that have a sticky back and they should just stick right to the plane. I would of course make sure the plane is complety clean prior to sticking the weights on. If your local hobby shop does not have the weights, go to your local tire store. They should. Good Luck. Dave

_____________________________

If the screw ain't loose then things ain't normal.

Dave Agar
AMA#97144

(in reply to Fredsterman)

Post #: 2

RE: Nose heavy AirCore 40 Trainer - 10/5/2007 3:25:30 PM

Muldoer

Posts: 115
Joined: 5/10/2005
From: , QC, CANADA
Status: offline

quote:

ORIGINAL: Fredsterman

My instructor checked the CG with a full fuel tank

Thats a HUGE mistake. CG should always, always, always (enough always'szs?) be checked with an EMPTY fuel tank.

If after you have checked your CG with your fuel tank empty you still have it nose heavy, then you can add lead weights as suggested. Securing them will depend on the way make your weight really. Normally I would just tape them on, then fly and check if it helps the flight characteristics.

(in reply to Fredsterman)

Post #: 3

RE: Nose heavy AirCore 40 Trainer - 10/5/2007 9:51:36 PM

AERORICH

Posts: 294
Joined: 4/21/2006
From: Scappoose, OR, USA
Status: offline

Hi Fred: I am really puzzled in that I have never heard of this plane being nose heavy before. Our club had one as a novice trainer without any nose heavy problems. Probably the engine installed was much lighter. Most of my models always come out tail heavy no matter how carefully they are built. I would suggest asking one of your club members if they had a used LA .40 to loan you to power this plane rather than add more weight to the model. My SuperTiger when removed from my SPAD created a real problem when removed for another engine installation because it weighed so much. Picking a lighter engine could solve your problem. BTW, you did not mention where the RX battery was located.

AERORICH73@COMCAST.NET

(in reply to Fredsterman)

Post #: 4

RE: Nose heavy AirCore 40 Trainer - 10/5/2007 11:23:17 PM

Mike in DC

Posts: 935
Joined: 8/14/2003
From: Washington, DC, USA
Status: offline

quote:

ORIGINAL: Fredsterman

I have an Aircore 40 trainer, that is very nose heavy. The engine is a Super Tigre .45 abc.
I have tried moving the "CG" aft. But the fuel tank is hitting the front wing dowel.

Like Aerorich, I'm really puzzled. I've built two of these planes, both trikes, and both with engines that weigh around 17 oz, which is quite a bit more than your Super Tiger (at least according to Tower Hobbies web site which gives the weight as 13.2 oz). That means that, if anything, your plane should be tail heavy (since your engine is lighter than mine), and all you have to do would be to move the "power cartridge" forward to balance the plane. I suppose you could be using a very heavy receiver battery (something other than the standard 600mA batteries typically packed with a radio set), but the battery sits very close to (or behind) the CG, so it's hard to imagine it's that big of a difference. Are you using the stock hardware?

I'd do almost anything not to add weight to an Aircore because it's a lumbering, heavy plane to start with.

I'm wondering if the problem is just that you balanced it with a full tank. The tank is probably a bit in front of the CG, so that could be it. There is no question that the Aircore needs more elevator throw than the instuctions specify, and it may be hard to land it with the throw specified in the instructions (you'll be at full up elevator almost all the way down to the runway).

In what way was your first flight ugly? Maybe it had nothing to do with the CG? I'm not sure it matters so much on a relatively heavy trainer like the Aircore. After all, the CG is going to change a bit anyway as you use fuel, and as a beginner there's no way you'd notice the difference. How far (in inches) do you think you were off the spar (I think that's the desired CG, if I remember)? Most planes have a range in which they'll fly fine.

The plane should fly like a heavyish trainer. In other words, it will react sluggishly to the controls and be somewhat self-righting. It likes to fly ovals around the field, and will not roll without losing a lot of altitude.

< Message edited by Mike in DC -- 10/5/2007 11:24:01 PM >

(in reply to Fredsterman)

Post #: 5

RE: Nose heavy AirCore 40 Trainer - 10/6/2007 12:57:55 AM

MrGreenSpeed

Posts: 622
Joined: 12/31/2002
From: Lakewood, NY, USA
Status: offline

I have to agree with every one else.
I used a mag40xl BB engine and had the battery in the nose as close to the engine as possible.
The spad thing to do would be remove the elev and rudder servos and move them back towards the tail, as well as the battery.
You may have to use extensions on the wires. Try to move gear that's in the plane before adding dead weight.
Use double sided tape and zip ties to mount them.
Reviewing spad plans at spadtothebone.com will give You a lot of info and ideas.

Go to tail dragger gear, as long as You have a little toe-in on the main wheels You won't have a problem with take off and landings.
I had a blast with My Aircore 40
Hope You get Your CG corrected soon, and have fun.
Jeff

(in reply to Mike in DC)

Post #: 6

RE: Nose heavy AirCore 40 Trainer - 10/6/2007 7:23:39 AM

kbear

Posts: 295
Joined: 9/11/2004
From: Denton, TX, USA
Status: offline

A good description of what made it a handful in flight would give us a better idea of the problem. Bad CG placement tends to produce specific characteristics based on the direction it is off. For example descriptions like sensitive to control inputs would lead me to think it was tail heavy. Sluggish, or little response to control inputs sounds nose heavy. Did you build it yourself, and did you have help. Not trying to knock your skills here, but if things aren't put together right, it can cause problems. Check the balance with an empty tank. It should be right around 1/4 of the wing cord (Leading edge of the wing to the trailing edge of the aileron). if your having a lack of control, Make sure you have strong enough control rods and the recommended control throws or better on the elevator. IMHO, 4-40 or better on a 40 sized bird or larger. 2-56 is just asking for trouble unless it's very short. If your rods are to light they will flex in flight and you will get less trow thus less control. What is your instructors experience. Again, I'm not trying to knock anybody here, but balancing the plane full of fuel and handing control over to you when he is having trouble with it sounds as if he is not greatly experienced. As for your actual question, Welder or Goop glue will hold things to coro very well. I have used this kind of glue to hold servos still, among other things, and it takes quit a bit of force to remove them when I want to put them to use in another plane. Give us some more info, and we always want to see pictures. Lots and lots of pics. Hope you get her sorted out, as this is such a great hobby to have.

(in reply to MrGreenSpeed)

Post #: 7

RE: Nose heavy AirCore 40 Trainer - 12/5/2007 8:34:41 PM

n8mkr

Posts: 71
Joined: 10/15/2007
From: Akron, OH, USA
Status: offline

Fred / Anyone:

I have one of these planes. I purchased it already assembled (poorly I might add) from a guy at work. It had a Thunder Tiger 40 on it which was really too little engine for this plane, but it did pull it around. I replaced the TT 40 with a Super Tiger 51 which works much better.

All that said, I did not get any paperwork for this plane and have no idea where the factory says to check the CG. Can you tell me per the instructions where the balance points under the wings should be?

This plane is such a pig that I would gut it and put the guts into something nicer, but it's ability to take punishment has prompted me to complete my training on it and then have my children learn on it too. I really does fly OK. When all the cheap paint wipes off from the exhaust residue, I plan to rename it the Swine Hund or Pig Dog. It is my first plane and the plane I love to hate. I have learned a lot from it.

John

(in reply to Fredsterman)

Post #: 8

RE: Nose heavy AirCore 40 Trainer - 12/6/2007 12:02:56 AM

MrGreenSpeed

Posts: 622
Joined: 12/31/2002
From: Lakewood, NY, USA
Status: offline

Where is Your CG now ?

I had Mine on the center of Spar.

What does Your AC-40 weigh ?
Mine was 4.5lb and I put 3" of dihedral in the wing.

The best thing I did was to add 3 flutes of 4 mil coro to the cord of the rudder and elev control surfaces and had dual aileron servos.
Good luck.
Jeff

< Message edited by MrGreenSpeed -- 12/6/2007 12:04:35 AM >

(in reply to n8mkr)

Post #: 9

RE: Nose heavy AirCore 40 Trainer - 12/7/2007 4:20:36 AM

OzMo

Posts: 1434
Joined: 9/2/2002
From: OZark, MO, USA
Status: offline

Drill a pair of holes in your weights and zip tie em on the bottom of the horizontal stabilizer. That is IF you really need weight. no glue or sticky stuff will work long on oily coro.

_____________________________

Yes dear, I did glue my hand to the airplane to keep from dropping it.

(in reply to MrGreenSpeed)

Post #: 10

RE: Nose heavy AirCore 40 Trainer - 12/24/2007 2:53:17 AM

combatpigg

Posts: 9784
Joined: 11/22/2003
From: arlington, WA, USA
Status: offline

Without adding weight to an already heavy plane, move the wing forward about an inch or so.....

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Led Zeppelin is NOT "old fogie" music.

(in reply to OzMo)

Post #: 11

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