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Center of gravity

PostPosted: Tue Mar 25, 2014 9:52 am
by ngaireross
I am rebuilding my flying saucer and need to know the starting point of the centre of gravity for a disk.( i.e. circle.
Diameter 1 metre)

Because it is a flying wing it will tuck under if it gets too tail heavy and I don't want to build this model too often.

Ross Mac

Re: Center of gravity

PostPosted: Wed Mar 26, 2014 3:26 pm
by jonathanshorer
I've built and flown a "Nutball" which is a circular flat plate Depron wing and balanced it at 1/3rd chord which seemed to work.

Sounds like a magazine article on the way!

Re: Center of gravity

PostPosted: Tue Apr 08, 2014 10:12 am
by ngaireross
Thanks Jonathan.

Sounds like a good starting point

Re: Center of gravity

PostPosted: Sat Nov 01, 2014 10:46 am
by darticus
I want to find where the CG would be on my 20 inch Nutball. What does 1/3rd chord mean as was mentioned earlier in the tread. Thanks Ron

Re: Center of gravity

PostPosted: Sun Nov 02, 2014 8:10 pm
by tigger
Hello Ron, in reply to your question on 1/3 cord. If you take the distance from the leading edge to the trailing edge this will be the chord length. Now divide this measurement by three and that will be the distance from the leading edge for your C of G reference. Remember this is just a good starting point and you may find you have to alter it slightly. Hope this helps and don't hesitate to ask again as there are some great builders/pilots on this forum.
Cheers Tigger

Re: Center of gravity

PostPosted: Mon Nov 03, 2014 2:43 am
by darticus
Very good answer. Now would the same apply to a dished shaped plane like a Nutball that is a 20 inch diameter? Thanks again Ron

tigger wrote:Hello Ron, in reply to your question on 1/3 cord. If you take the distance from the leading edge to the trailing edge this will be the chord length. Now divide this measurement by three and that will be the distance from the leading edge for your C of G reference. Remember this is just a good starting point and you may find you have to alter it slightly. Hope this helps and don't hesitate to ask again as there are some great builders/pilots on this forum.
Cheers Tigger

Re: Center of gravity

PostPosted: Mon Nov 03, 2014 4:13 pm
by tigger
Try 5 to 6 1/2 inches from the LE and give it a toss, no power and see if it glides. Play around with C of G until it does.
Cheers Tigger

Re: Center of gravity

PostPosted: Tue Nov 04, 2014 12:57 am
by darticus
Thanks, it seems to be balanced at 5.5 inches. Now to test glide on a bed. Thanks Ron

tigger wrote:Try 5 to 6 1/2 inches from the LE and give it a toss, no power and see if it glides. Play around with C of G until it does.
Cheers Tigger