I've used ca hinges in the past but now I'm using the hinge points. My question is how many of you guys wallow out the hinge hole so there is no gap or do you leave it and seal the gap another way? What is the max. gap until flutter starts? 1/8th to much?

I ream out the holes, with a Dremel with a pointy nosed cutter, till the hinge pin is flush with the back of the wing and front of the aileron.

In general, it is not the gap that causes flutter, it is play or slop in any portion of the control linkage or flexible control surfaces. A gap will cause the control surface to be less effective but rarely contributes to flutter.

I use a phillips screw drive to ream out the holes for medium sized hinges - I think it is a #1.

RCPAUL

While a control surface gap, in itself, will not cause flutter, if there is any tendency to flutter a gap will aggravate it.

The pictures show the empennage of my Electra, the TE of the fixed surface is concave, with the rounded edge of the control surface inside the concavity. effectively zero gap. The second picture is a closer shot on one hinge. I used the Robart Hinge Points.

Bill.

You will find a lot of discussion about installing Robart hinge points in this tread under Tips and Techniques. I used CafeenMan's link and found a wealth of info about hinge points. I installed them with the hinge in the radius of the leading edge of the control surface which makes a lot of sense to me.

Here is the link: http://www.rcuniverse.com/forum/CA_H...1213711/tm.htm

I leave a small gap then seal the hinge line at max throw,this way I don't have to worry about the hinge trying to pull itself out at max control.