I wish I can find a simple warping system , but I think for this one I will go with rudder/elevator control .Maxx
Your are aware the full size Eindecker had no dihedral and used wing warping rather than ailerons.
I found this video , so finally I will try and go with the warping wings . That's the kind of simple I wanted .Maxx
Your are aware the full size Eindecker had no dihedral and used wing warping rather than ailerons.
Thank you for taking the time to share your experience . Very much appreciated !a year ago or so I did my own wing warping E1. The tail was simple enough using Pull-Pull control lines and the wing also used a pull-pull setup on a large loop through both wings.
The guy wires were braided fishing line to reduce the stretching over time.
Whilst I managed to get it airborne I classed the effort as a failure due to the very short nose and the need to add significant weight to get it to balance properly. The extra weight made it very sluggish in the air and difficult to control as the speed fell away on landing.
The aileron servo needed to have significant torque as I did not remove the paper from the wing at all As for the warping itself the inboard section of the wing must NOT be connected to the fuselage from the approximate balance point and the moving of the inboard section of the wing is in excess of the tip movement.
If the build is light enough a half inch of movement is plenty for the warping and the wings can have dihedral for the first flights using the fixed guy wires and later reduced to no dihedral after a few proving flights. The most difficult part is the attachment of the guy wires to the wing, (I embedded toothpicks into the wing with the guy wires attached). Fine adjustment of the guy wire lengths and the tension therein can be difficult and it caused me much drama initially.
The real design trick is to keep the tail and the tail boom extremely light or you will need a huge amount of lead to get it into the air. Extending the fuselage forward a small amount can help a lot in balancing.
Watching with interest!
Have fun!
Thank you for sharing your experience , I took notes .a year ago or so I did my own wing warping E1. The tail was simple enough using Pull-Pull control lines and the wing also used a pull-pull setup on a large loop through both wings.
The guy wires were braided fishing line to reduce the stretching over time.
Whilst I managed to get it airborne I classed the effort as a failure due to the very short nose and the need to add significant weight to get it to balance properly. The extra weight made it very sluggish in the air and difficult to control as the speed fell away on landing.
The aileron servo needed to have significant torque as I did not remove the paper from the wing at all As for the warping itself the inboard section of the wing must NOT be connected to the fuselage from the approximate balance point and the moving of the inboard section of the wing is in excess of the tip movement.
If the build is light enough a half inch of movement is plenty for the warping and the wings can have dihedral for the first flights using the fixed guy wires and later reduced to no dihedral after a few proving flights. The most difficult part is the attachment of the guy wires to the wing, (I embedded toothpicks into the wing with the guy wires attached). Fine adjustment of the guy wire lengths and the tension therein can be difficult and it caused me much drama initially.
The real design trick is to keep the tail and the tail boom extremely light or you will need a huge amount of lead to get it into the air. Extending the fuselage forward a small amount can help a lot in balancing.
Watching with interest!
Have fun!
Or you could reverse the warp by having the wing root move the most and have the tips solid, may take some designing and experimenting but it could be done.There is of course a good reason why wing warping was dropped in favour of ailerons other than for structural reasons.
If you think about it warping creates 'wash in' on the wing that is trying to create additional lift so any stall is almost bound to start at the tip first which exactly what you don't want particularly on a slow flying plane with a thin section under cambered wing.
I suspect some form if differential warping (more twist on the 'down' wing than on the 'up') would be beneficial but not so easy to arrange.
It would eliminate the need of a non-twisty rod since it's so close to the servos . I think it would work , but kinda funny on the scale side .Or you could reverse the warp by having the wing root move the most and have the tips solid, may take some designing and experimenting but it could be done.
The physics of aerodynamics dictates that is probably the way they should have done it in the past. It has advantages in two ways. The inner span of the wing needs more throw because there is less leverage, and the tips will stall last due to 0 angle of attack. If you had a solid spar running all the way to the tips supporting free rotating ribs to the root in my head it would work. It would also be a easier to fly I am guessingIt would eliminate the need of a non-twisty rod since it's so close to the servos . I think it would work , but kinda funny on the scale side .
O.K. I get it now ! Thank you , that makes a lot of sense .It is very important that the wing LE on a warping wing does NOT move up and down under roll control. With TE warping the forces on the roll control input are progressively increasing with roll input whereas a moving LE will produce an additive roll input and eventually the aerodynamic forces will want to maintain full warp angle or rip the wings off of the craft.
Before powered flight controls the way they reduced control stick forces was with balanced control surfaces and the portion of the control surface LE that was moved was very small as the forces generated by the balancing portion of the control surface were far greater, (for unit area), than the portion of the control surface TE that was moved.
Effectively you need to make the front portion of the wing very rigid and only warp the wing TE. Wing warping designs generally have fixed guy wires to stabilize the LE and a set of guy wires on the wing TE that were able to be moved under control stick input.
Without locking the wing LE geometry a gust of wing will cause serious roll issues and even the stripping of the aileron servo/s.
Just a thought!
have fun!