darticus

My foamy usually dives when I do a roll. What would be the reason? Speed? CG? Thanks Ron

Leo L

Almost every plane dives when it does a roll. The reason is that when the plane starts to roll, it looses the lift from the wings as the wings begin to tip. It continues to loose lift until it is flying on it's side, when there is virtually no lift. As the plane continues to roll to the inverted position it gains lift until it is completely inverted. As it continues to roll past the inverted position, it once again looses lift, etc.

To counteract this loss of lift and the consequent dive, there are a number of things that can be done.
1) Give up elevator just before you start the roll.
2) Increase the roll rate by making larger control surfaces.
3) Increase the roll rate by increasing the deflection of the control surfaces.
4) Increase the flow of air over the control surfaces by increasing the speed of the plane.
5) Increase the flow of air over the control surfaces by using a larger prop.

3D and 4D planes rely mostly on the thrust of their props to keep them in the air, rather than on the lift generated by the wings, so these planes do not "dive" nearly as much when they perform rolls.

Witterings

As Leo L has explained why they loose lift the other way to stop it dropping and it takes quite a lot of practice to get right but if you're rolling to the right, as the plane is virtually on it's right hand side feed in left rudder to compensate and keep the nose up, you then ease off rudder as the plane goes inverted and feed in down elevator, as it continues round to be on it's left side ease off down elevator and feed in right rudder and as you start to come back up to level flight come off the rudder. Where you see video's of people doing axial ie flat rolls without loosing height that's exactly what they're doing and where you see rolling circles they're just doing it again and again and again.

To start off and in it's simplest form give a touch of up before you start the roll, then give some down when you're inverted and ease off again as you continue to come back up towards upright and you'll find it helps. When you don't have to think about that any more and it's natural and smooth start introducing the rudder as described above. I had a couple of knee operations at the beginning and middle of last year and whilst recovering I just sat for hours on a Simulator practicing exactly that again and again and again !!!!!

darticus

Thanks for your help. Maybe the realflight 3.5 simulator can help but not sure. Ron

Witterings

Ron,

Even the cheap FMS Simulator is great, I'm sure the more expensive ones are better but I've learnt most 3D on FMS which was £17 with a TX and the just found sites to download 3D planes like the E-flight Mini Funtana Min Edge and the Seb Art Katana all of which are quite realistic.
That said I can't be that good as I destroyed my Acromaster which I've learnt 3D on in the last year yesterday morning prop hanging it and it came back over the top on me and I couldn't recover it []

darticus

When they come over you I usually lose them also. Ron

phillipmorris

Wonderful descriptions on completing the roll, what took me awhile was to give down elevator while its inverted, seems like the wrong thing to do but is exactly whats needed as things are topsy turvy....later when you advance to faster planes only a held left or right will do a single lightening roll, example my recent entry a jet pusher, does a lightening roll due to its speed...now love rolls, are super fun...<>...

Yes the view directly overhead can be difficult at times to tell whats happening, only a few weeks back made a huge error in taking my eyes off a flying wing, the Stryker B as it went directly overhead as only second later after I spun around it was already into the turf, ykes, don't take your eyes off even for a second, best to simply keep the plane upwind infront for improved visual..<>..