How to use an incidence meter?

[Paul Taylor]

Can someone tell me how these are used?

Thanks
Paul

[Peter Ferguson]

The most common usage of an incidence is to check the incidence angle of the horizontal stabilizer vs the wing. Most airplanes require that the tail be in alignment or within a degree of the wing angle of incidence.  A Robart incidence meter has a provision that will fasten to the engine crankshaft so you can check the wing and tail incidence vs the engine thrustline. Additionally, incidence meters are handy for detecting wing warps, you can take a incidence measurement in several places along the span of the wing to see if it has a twist in it or you can accurately measure the washout of the wing if you want to build that in. It is a very handy tool to have as it reduces the amount of measurements you have to make from a Datum in order to build a straight airplane.

[Steve Helmick]

It's a bunch easier if you have two or three incidence meters, so you don't have to move one all over, and hope that you didn't move the model in the slightest! Best deal is for you and your buddies to buy one each, and team up on alignment chores.

If the specifications mean anything, the Robart unit is twice as accurate as the high-tech laser job. I'd like to know which is preferred by those who've used both. I got two Robarts, but so far have only used one of them.
  Steve

[Randy Powell]

Yea, I have two of them and will probably pick up a third. Useful little buggers.

[Peter Ferguson]

Hobbico has discontinued the sale of the laser ones. Sales may have dropped off. I would be interested too as I've never used one.

[PeteBergstrom]

Just curious and looking for feedback.  Did anyone ever try one of Hangar 9's Angle-Pro's? 

http://www.horizonhobby.com/Products/Default.aspx?ProdID=HAN192

Thanks for the help.

Pete

[Bob Reeves]

Just curious and looking for feedback.  Did anyone ever try one of Hangar 9's Angle-Pro's? 

http://www.horizonhobby.com/Products/Default.aspx?ProdID=HAN192

Thanks for the help.

Pete

Wow, wasn't aware of it.. Will for sure have to add one to my tools collection as soon as I get my mad money account built back up.

[Dwayne]

Being the level headed guy I am this is how I use mine...    
 Just kidding Peter has it nailed. Mount the engine in the plane then place it on a flat surface and check the angle of the engine, shim the fuse until it is at zero then move the meter to the wing and tack the wing in place then do the same for the stab.
Hope this helps

[Leo Mehl]

Its what I use and it sure makes a difference in how strait the Incedents are. On my Odessay I put .8 positive incedence in the stab and that plane sits right in the groove upside or downside. Worth every penney.

[Peter Ferguson]

As they say a picture is worth a thousand words. I haven't updated my tools in awhile . They are still analog and my Robart uses a penny as the pointer weight.  That H9 looks like a nice meter and for those mathmatically challanged it can be used to set thrust offset.
Also, having a deflection meter is very useful (more so in R/C) but its nice to measure flap vs elevator deflections or twist in your flaps (I know, that only happens to me).

[Kim Mortimore]

With my Robart I found the bearing on the pointer inadequately smooth for the tiny angles we are attempting to measure.  I assumed the motion of the pointer would be smooth and continuous if I rocked the meter slowly back and forth, but it was not.  The bubble level seemed more useful, though not quantitative for angles other than dead level. 

Once the flaps and elevator are installed, taking measurements is difficult at best.  On the tail I suppose you can use strips of balsa and rubber bands to immobilize the stab(?)

Brett Buck once said, "an incidence meter can tell you what you have but not what you need."

And given the great difficulty of fixing faulty incidence on a finished planes of most designs (if cranking in a little down elevator doesn't do it),  maybe some form of variable incidence stab might be an answer. 

Kim Mortimore

[Peter Ferguson]

Kim, The Robart has some shortcomings, I think the H9 unit addressed them with their digital inclinometer.

My opinion is it is more of a building tool rather than a troubleshooting tool. I would think most builders fit their hinged surfaces after they have the wing and stabs set.

With all respect to Brett; He's right but I think in this case knowing what you have is better than not knowing. (this may not be true in all aspects of life!)

[Kim Mortimore]

Kim, The Robart has some shortcomings, I think the H9 unit addressed them with their digital inclinometer.

Sounds interesting, will have to check it out.

My opinion is it is more of a building tool rather than a troubleshooting tool. I would think most builders fit their hinged surfaces after they have the wing and stabs set.

Good point.  Wasn't it Aretha Frankin who said, "An ounce of prevention is worth a pound of cure."?

With all respect to Brett; He's right but I think in this case knowing what you have is better than not knowing. (this may not be true in all aspects of life!)

I'm confident he would agree with that.

Thanks for your message.

Kim

[Derek Moran]

Make your own!  See November 2006 MA.
Derek