Wing/tail incidence

Folowing on from the trim chart thread I pose a quick question. Do we take ARTF`s for granted?

M

I check it I've got a cool little angle-o-meter that has a magnetic base, which is really handy for measuring, er, angles.

Also, if you have an iPhone, you can donwload a little angle measuring App for it called iHandy (seriously!). It is really, er, Handy, and the resolution is down to 0.1°, It is surprisingly accurate too!

Andy

just thought it would be intresting to see who dose, if im honest i never do, as long as somthing looks right i`ll fly it lol, However the Suk will be done properly and i know my edge was

M

Havn't checked one since my last build which was A.H's Ultimate. Everythings been ARTF since then and I've not had one so far out of trim to arouse any suspicion about an incidence incident

I must admit I used to take the incidences on ARTF's for granted 'till I got caught out with my Extra 260EP.

Whats this?!?!?!

Looks like a question mark followed by an exclamation mark X3 to me Sam

I voted for 'last plane I built' as I am of the opinion that ARTF are not built but assembled.

Talking of which, ARTF's can be near impossible to alter the wing/tail incidence on. Regular talk on this subject in aerodynamics articles in the model flying magazines. I think with ARTF's the way forward is build it...sorry, assemble it, fly it, adjust CoG and other things until your're happy, then check if the elevator is far of centre when trimmed for straight and level flight and then decide if it is worth doing anything about it.

Only F3A expert CPLR will start to alter the way the fuselage present itself (angle of attack) at straight and level. But then F3A planes are (were) often equiped with incidence adjusters for both wing and tail feathers.

My Cougar 2000 got the incidence slightly wrong after major rebuild, but do I care.....? NO.

I check every one of mine, be it own design, plan, kit or ARTF. Even ones from other people. I look at the drawings provided and also compare that with what I know should work.

Not just rigging but CG, engine thrust line, as well as left right balance of wing. AND of course radio control surface movements and directions. e.g. If I want aileron differential, is it actually working correctly?.

Do the fail safe settings work and are correct positions?????

All this before it even gets to the field

Highly suspicious of ARTF models from some bad past experiences with ARTF in the early days. But, having said that, its not easy to make big changes to ARTF's withouit half destroying the thing and getting into a whole rebuild and recovering job.

So I keep an eye on reviews and listen to others modellers adventures.
But even the reviews in the mags can be a bit too nice to be believable.

Don't forget to kick the tyres next time as well Paul

Sam Thomas wrote:Whats this?!?!?!

Sam, Incidence is usually the term given to the angle of an aerodynamic surface, with respect to the datum axis. For example, the datum axis on a plane, might be chosen as the thrustline. The wing incidence would be the angle of the wing mean chord(line) relative to the datum axis. The tail incidence would be the angle of tail mean chord(line) relative to the datum axis.

Sometimes the wing mean Chord(line) is chosen as the datum axis, sometimes it is an arbitary axis or line on the plane. For conventional models, the wing/tail incidence is nearly always positive by a couple of degrees....

HTH
Andy