Next plane advice

[franck102]

I have really been enjoying my ArtHobby Elster for the past 5-6 years, but the time has come to start looking for a new plane.
With quite a few repairs and a ruddervator setup the Elster is tough to keep in the air on light lift days (starting from a high start), and that is the key criteria I will be looking at when picking the next plane.

I love the ArtHobby quality (those wings are incredibly tough) for the price, so I am hesitating between the Boar and JK thermic, and between the aileron vs polyhedral wings.

I know polyhedral is more stable and typically recommended to fly flat field thermals, but I just love ailerons and the look of straight wings so I am thinking of adding some dihedral to a straight wing version... would this help stability in thermal turns? How much dihedral should I add without hurting the L/D and the speed range too much?

My other question is about the plane size: all other things being equal, how much better does a 2.5m (the JK thermic) fly as compared to a 2m (the boar)? More specifically, if two equally competent pilots go out regularly on light lift days from a highstart, how often will the 2.5m stay up (say for 4-5 mn) while the 2m just comes down in under 1mn?

Any advice appreciated!

[aeajr]

Are you asking specifically about Art Hobby planes or are you looking for recommendations of other planes as well. I have not seen or flown any of the Art Hobby planes so I can't provide input on them.

[John Cole]

If you like Art Hobby models, here's a thread to review;

http://www.rcgroups.com/forums/showthread.php?t=648449&highlight=art+hobby+ha

John

[franck102]

Are you asking specifically about Art Hobby planes or are you looking for recommendations of other planes as well. I have not seen or flown any of the Art Hobby planes so I can't provide input on them.

Well, those are general questions I guess. To put it differently:

- if an average pilot can just keep a 2.5m in the air on a light lift day, what would it take to keep a similar 2m in the air? Would the 2m stay up just the same 90% of the time or would it take the best thermal pilot in the world to keep it up?

- on a plane that is designed with aileron and a small center dihedral (probably 6-8 degrees), would increasing the dihedral help with stability of thermal turn? How much can I add without affecting other performance characteristics too much?

Thanks!

[aeajr]

These are plane designer questions Someone else will have to help you. I don't design planes.

[slopemeno]

I have a friend that flies his 2.5 meter Thermic with a flat wing with an elevator-only V-tail, and that thing will stay up on the slope while everything else is grounded. It'll core tiny weak thermals, but can get up on step and get away from sinky areas well. I'd build one as-is. They fly great, and are dead stable.

[franck102]

I have a friend that flies his 2.5 meter Thermic with a flat wing with an elevator-only V-tail, and that thing will stay up on the slope while everything else is grounded. It'll core tiny weak thermals, but can get up on step and get away from sinky areas well. I'd build one as-is. They fly great, and are dead stable.

Good to know, thanks. Can he make stable tight thermal circles with high bank angles?
I have a hard time with those on my Elster (a 1.5m sibling of the thermic - same design & airfoil). I have added ruddervator controls after reading those forums, hoping to learn to make coordinated turns but not much improvement for now, hence the question about dihedral.

[slopemeno]

Yes- not as tight as a dedicated handlauch, but he's able to exploit some small thermals close to the ground.