Replies to This Discussion

Permalink Reply by Björn Geir Leifsson on January 29, 2012 at 8:14am

Not sure what plane you are referring to. Do you have a picture?

From the information you give it seems that the thrust line of your motor is wrong. You may have to adjust it depending on how it is configured. If it is a puller (in the nose), it may have to much upthrust and you will have to apply downthrust to have it pull up the nose when throttling. If it is a pusher it will need to add upthrust. RC modelers often do these adjustments by putting washers between the firewall and the motor mount above or below.

Never trim or tune the flight characteristics of your plane via the APM. You should be able to fly your plane normally as a regular RC model, preferably with the transmitter trims neutral before using APM.

Cheers

Björn Geir

Permalink Reply by Ahmed Rehan on January 29, 2012 at 9:00am

It is flex wing with normal plane fuse underneath .

Permalink Reply by Björn Geir Leifsson on January 29, 2012 at 11:26am

Oh my, that certainly is an adventurous construction.  My immediate gut reaction is to say: forget it.

The classic Rogallo kite wing like yours, with a floppy sail and narrow angle is not a particularly good or efficient wing in an aerodynamical sense.  It was the first form used in the start of the hang gliding era but has long since developed over to much more efficient forms with a much wider angle and all kinds of improvements (e.g. ribs) to overcome inherent problems. In a sense they developed towards classical wings.

They were initially controlled by a tail fin (like your construction) but this was soon abandoned  as it was found to be much easier and better to use center of gravity shifting which is still used today. 

I am not surprised you have problems with flying this.

Of course you may prove me wrong one day but I doubt it is worth the time and effort to try to get this to fly properly in the first place and then get it to work safely under APM control.

(Public domain image linked from Wikipedia)

Permalink Reply by Ahmed Rehan on January 29, 2012 at 12:47pm

It fly very well under APM control only problem i am looking is auto take off . even auto landing will be much more easy under apm control . I dont know if apm will able to restrict climb angle with throttle or not at take off.  And it is very easy to fly for even a beginner Cyberbug is a UAV based on same theme.

 http://www.youtube.com/watch?v=UeCnJcR4YVY&feature=related

 

Permalink Reply by Björn Geir Leifsson on January 29, 2012 at 1:08pm

I never doubt it could be made to fly, a piece of paper can be made to fly.

What I doubt is that it is an efficient and safe wing and that it can be made to behave in other than calm and ideal conditions.

If this were a good wing, every other person would be using it, and their grandmother too.

The operational quality of the Cyberbug drone can be a matter of discussion, it does not look convincing to me in the tape you linked.

An autonomous craft using a Rogallo wing is not something I myself would put down time and effort to develop, even if it is dirt cheap and easy to make and probably hard to brake. Perhaps something like the modern ultralight wings but then you are again into complex and more expensive things.

As I said in the first reply you possibly have your thrust line way off. Having seen the aircraft I would guess you will also have to work with other aerodynamical factors, mainly the relative AOA of the wing, empennage and engine. APM software adjustments are not going to help much if it does not fly well in the first place.

Good luck :)

BGL