what is this and is this the cg - RC Groups
Thread Tools
Mar 20, 2012, 10:05 PM
Registered User

what is this and is this the cg

pics tell the story

what is it
and is this a good cg

Sign up now
to remove ads between posts
Mar 20, 2012, 10:12 PM
Gas Only
Fokker DII's Avatar
CG range for a straight wing is normally between 25 and 33% of the chord at the fuse. That looks like it is in the range.
Mar 20, 2012, 10:49 PM
Master of the Figure "9"
hogflyer's Avatar

The plane is a Sig Kougar.

The following is straight from the Kougar manual:

The recommended Center of Gravity locations are:

Test Fly with the balance point located anywhere between the leading edge at the wing tip and 1/2" back from the leading edge at the wing tip.

Sport Fly at 1/2" back from the Leading Edge at the wing tip.

Aerobatics - If your model will spin in both directions at 1/2" it need not be moved back any further. Some models need the balance point at 3/4" back for full response. Flying with the balance point any farther back than 1" from the tip is not recommended unless you are an expert flier, with a purpose for doing so.

For the first test flight, balance the Kougar by suspending it on the finger tips placed on the bottom of the wing on the first mark. Balance with an empty fuel tank, but with all other equipment installed and the model completely finished and painted. Add lead to the nose, if necessary, to get the model to hang level. Be sure and fasten the weight securely. Do not attempt flight tail heavy.

The "Test Flying" position is on the nose heavy side. When slightly nose heavy, the model is more stable and less likely to stall or snap roll from over-elevating. It also cuts down reaction of the model to control movements and this is good during test and practice flights, to help prevent overcontrolling. After the model has been test flown and initial trimming accomplished you may want a little quicker response. Move the balance back slowly and check results in the air.

Some aerobatic capability is sacrificed with the forward C.G. positions, so for making deliberate snap rolls and spins a position farther back may be required. Move the C.G. back slowly and check results and control response in the air at a good altitude. Don't move the C.G. back any farther than necessary.

Hope this gives you what you need.

Mar 20, 2012, 11:45 PM
Registered User
Thanks a ton that's what I was looking for weird you measure it the wing tips I thought you always measures at the root
Mar 21, 2012, 08:51 AM
AMA 537620
ChillPhatCat's Avatar
Originally Posted by nitrosportman
Thanks a ton that's what I was looking for weird you measure it the wing tips I thought you always measures at the root
It's just easier to measure the balance point at the wing tips with a swept leading edge like that... that way you don't need to measure exactly how close to the fuselage you need to balance it.
Mar 23, 2012, 12:55 AM
Registered User
MINI0012 (5 min 1 sec)

she flew it was still tail heavy though, elevator was way to weak but it looked like the push rod was bending it wasn't doing that before flight oh well replaced that

broke my prop on landing and didn't have an extra with me so i was done for the day
Mar 23, 2012, 08:12 PM
Registered User
well gents i can tell you 1/2 inch back is not correct i proceeded to just barely get it in the air and subsequently right into the ground not much damage another broken prop popped the canopy off

im gonna take the lead out repair it and just start moving the cg forward till i find a good balance at least i know it flies at the thick part of the wing
Mar 27, 2012, 10:30 AM
Registered User
RIP sig kougar!

never could get the cg right it was so twitchy throw on the elev was set to 3/8" it was either straight up or straight down it eventually just became too much to handle and i had scrubbed off all my altitude and it decided it wanted to be a part of mother earth broke the wing in half

it's been a bad month for me luckily my a10 edf is still flying perfectly so i can stay in the air and my new motor arrived for my heli

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Ace 4-40 bipe..What is the CG & control throws? eng30 Fuel Plane Talk 3 Dec 13, 2011 07:55 PM
Help! Help identifying this plane - Silky Wind 400 - CG ? MarLi Electric Plane Talk 8 Nov 28, 2011 07:08 PM
Discussion Fighting CG, thrust angle, and trim. Should a super decathlon be this difficult? stgdz Electric Plane Talk 30 Oct 02, 2011 01:02 PM
Discussion Plane lands waaay fast; what does this say about the CG? Andrew McGregor Electric Plane Talk 26 May 18, 2007 10:36 AM
What's the CG of this? ...... Doc Watson Power Systems 11 Jun 16, 2001 10:26 AM