RC India

RC Models => Electric Planes => Topic started by: TEJASCOOL007 on August 08, 2009, 10:30:47 PM



Title: HOW IS CG RELATED WITH RC PLANES
Post by: TEJASCOOL007 on August 08, 2009, 10:30:47 PM
hello friends....
      can u help me out with the CG part of the plane how to check it or rather rectify it..???
                                                                                                        regards,


Title: Re: HOW IS CG RELATED WITH RC PLANES
Post by: sahilkit on August 09, 2009, 01:06:25 AM
hi tejas

read this should help clear up some questions,may be other will have some thing better

http://www.allstar.fiu.edu/aero/axes33.htm
http://www.allstar.fiu.edu/aero/axes32.htm
http://www.allstar.fiu.edu/aero/axes31.htm

sahil


Title: Re: HOW IS CG RELATED WITH RC PLANES
Post by: sahilkit on August 09, 2009, 01:11:14 AM
CG of a plane generally lies between 25% to 30% of wing chord depending on your CG position the planes characteristics change from less sensitivity to more or over sensitive to input control.

sahil


Title: Re: HOW IS CG RELATED WITH RC PLANES
Post by: atul_pg on August 09, 2009, 10:07:20 AM
Hi

Check this CG Calculator, it may solve some of your questions ?

http://fwcg.3dzone.dk/

cheers

atul g.


Title: Re: HOW IS CG RELATED WITH RC PLANES
Post by: allthatido on September 01, 2009, 02:44:39 PM
the more the cg is aft more sensitive is the pitch control. Actually its the difference between the cg and center of pressure that decides the turning moment(pitching).


Title: Re: HOW IS CG RELATED WITH RC PLANES
Post by: Sreedhar on October 10, 2010, 07:43:54 PM
Hai guys i am having problem.. I have a cessna... the thing is i cant use a 2200mah on it it makes nose heavy... there is no space to place it else where.. when using 1000-1500mah i get perfect cg... What should i do... I want to use 2200mah to get more flight time..
Please help


Title: Re: HOW IS CG RELATED WITH RC PLANES
Post by: anwar on October 10, 2010, 09:46:32 PM
Use the 2200mAH and add some tail weight for compensation (ie, tape in some coins or bolts around the tail area).  You may be undermining the electrical setup by causing the plane to be too heavy by doing so, proceed with caution.  Flying characteristics MAY also get affected as the plane grows heavier.


Title: Re: HOW IS CG RELATED WITH RC PLANES
Post by: Sreedhar on October 10, 2010, 09:58:48 PM
i have a doubt... if we want to lift heavy weight should we use a motor with higher kv or low??

currently i am using a 1100kv turnigy motor wit 9" prop... i want to change the motor and also include the 2200mah.. so weight is gona rise... should i use a motor with higher kv and smaller prop???
The model is a TW CESSNA... (chinese) but well built and some what strong.
...


Title: Re: HOW IS CG RELATED WITH RC PLANES
Post by: anwar on October 10, 2010, 10:04:26 PM
Hmm, you should look at thrust (the ability to carry/pull weight).  Since this is a Cessna, you are better off in general with a "medium-low" (can't think of a better way to put it) KV motor than a high KV one.

You can get motors of various thrusts in the same KV range, if you wanted to.