Vector ARC Wing/Stab Incidence

[Joe Rice]

I am ready to epoxy the wing and stab on my Vector ARC and was wondering if any of you Vector ARC/ARF builders check the incidence angle of the wing and stab before assembly.   

Joe

[John Tate]

The last Vector ARC that I put together had some negative incidence. I had to put a 1/16” shim under the front of the stab to get it inline with the wing.

John Tate
Norfolk Aeromodelers

[Dick Pacini]

The last Vector ARC that I put together had some negative incidence. I had to put a 1/16” shim under the front of the stab to get it inline with the wing.

John Tate
Norfolk Aeromodelers

I think that some builders find that advantageous, although there is some controversy about it.  Same goes for rudder and engine offset and longer inboard wings.

In the case of the Vector, I would think Randy Smith, the designer, would be the one to ask.  Maybe he will jump in here.

[john e. holliday]

I have always been taught that everything should be on a zero plane.   Especially on semitrical airfoils.   But, I see some of our best stunt pilots talk about using positive/negative incedence on their planes.   Even the great Al Rabe talks about semi semitrical airfoils.   Everybody has their method and ideas about what works.   So if you ask me I would line everything up with the thrust line of the engine.

[Dan Bregar]

Yeah Doc, I'm with you.  I always went zero-zero.  However my flying buddy has a ARF Vector 40 and watching it fly it seems to fly level laps with a nose high, tail low attitude.  I know that a symmetrical wing has to have a slight positive angle of attack to develop lift, and wondered if it was aligned in the fuselage with that slight positive angle, then the wing would be positive but the profile of the fuselage would seem to be level flying by as you watch it go around the circle in level laps. I thought perhaps the ARF had the wing at a slight negative angle which makes the wing needing to fly at a positive angle, the visual cue of the fuselage being nose high and tail low.  I have observed other stunters with this fuselage nose high, tail low flying style and wondered what caused it.  Maybe smarter guys than me can comment. 

[John Miller]

A couple of years ago, there was several threads on the forum about this subject. I really don't want to type the whole thing again, so please do a search. Start with "Things that always work", a post by Bob Whitely.  Then, enter a search under down thrust.

[Joe Rice]

A couple of years ago, there was several threads on the forum about this subject. I really don't want to type the whole thing again, so please do a search. Start with "Things that always work", a post by Bob Whitely.  Then, enter a search under down thrust.

I did a search as suggested and found quite a bit of discussion on the topic.  It looks like I am getting an incidence meter before mixing the epoxy.

Joe

[John Miller]

Joe, getting an incidence meter is a great idea. We just cannot use the mark 1 Eyeball, to set up the thrust, wing, and stab.

Using one makes it a lot easier to set a plane up to fly right.

[Joe Rice]

Joe, getting an incidence meter is a great idea. We just cannot use the mark 1 Eyeball, to set up the thrust, wing, and stab.

Using one makes it a lot easier to set a plane up to fly right.

Thanks, John.  I have one coming from an on-line vendor. 

Joe

[RandySmith]

I am ready to epoxy the wing and stab on my Vector ARC and was wondering if any of you Vector ARC/ARF builders check the incidence angle of the wing and stab before assembly.   

Joe

HI Joe

Put 1 degree postive in the stab/elev, and whatever you do ,do not have any negative.
Some people also set all 0-0-0 the put 1\16 inch drop in the elevators..this is effectively positive incidence ,and will do mostly the same thing

Regards
Randy

[Joe Rice]

HI Joe

Put 1 degree postive in the stab/elev, and whatever you do ,do not have any negative.
Some people also set all 0-0-0 the put 1\16 inch drop in the elevators..this is effectively positive incidence ,and will do mostly the same thing

Regards
Randy

Randy, Thanks.. I really appreciate your reply to my inquiry. 

Joe

[Serge_Krauss]

A SSW Forum search on "Stab Incidence" will get you almost 12 pages of citations, some of which have some good discussion.

SK

[Joe Rice]

A SSW Forum search on "Stab Incidence" will get you almost 12 pages of citations, some of which have some good discussion.

SK

The designer hath spoken, so let it be done.

Joe