RC India

RC Models => Electric Planes => Topic started by: tg on October 15, 2009, 10:28:03 AM



Title: Wing span and fuse length
Post by: tg on October 15, 2009, 10:28:03 AM
Hi,
     Can anyone comment on the relation between fuse length and wing span. Assuming that you choose to build a model with a wing span say x and chord y, is there a specific formula that decides what should or must be the fuse length.


Title: Re: Wing span and fuse length
Post by: allthatido on October 15, 2009, 11:48:02 AM
Hi tg

lets say our span is "S" , chord is "X".

Now Aspect Ratio(A.R.) = S/X.

The length of the fuse in front of the wing = 1 or 2 times "X".
                       = 1 or 2 times "(S/A.R.)".

The length of the fuse behind the wing = 2 or 3 times "X".
                                 = 2 or 3 times "(S/A.R.)".


There is no standard fixed formula for rc aircrafts. If you have a long fuse behind the wing you will have large pitching moment...So you need less elevator area. It basically depends on what you want your plane to do...aerobatics, stable flyer. you'll notice that 3d foamie planes have exceptionally large control surface areas..that because the design requires so..they fly by propellor and not wings.

So it would be more clear if you decide what sort of plane you want.


Title: Re: Wing span and fuse length
Post by: izmile on October 15, 2009, 11:54:00 AM
This should give you an idea - http://indiarc.com/modeldesign.htm


Title: Re: Wing span and fuse length
Post by: tg on October 15, 2009, 12:31:12 PM
Thanks Ankur and Ismail. Will check the kit that I've got. Its a sport foamy flyer that I purchased long time back. The seller makes only cores and the span is 48", the seller was advising to trimming the span to 36". So wasn't sure.