You didn't say who makes it, what size, if it was covered, or if it's a balsa or foam kit. Do the directions say to hinge from the top? If so, this is building in differential, unusual in an aerobatic plane. <div>
</div><div>As you're using robarts, I'll assume it's an uncovered balsa plane. If it's a small plane ( below .40-size), you'll need the smallest robarts made. Robarts require a fair amount of good, rigid structure due to their diameter and length. Also, they require the most accuracy in drilling to prevent binding. I build a drill jig for that reason. </div><div>
</div><div>You'll need to bevel the leading edge of the surface. This is best done by placing the surface at the edge of a table and sand at a 45-degree angle with a sanding block or bar (the longer, the better). Another easy way to accomplish the bevel is to glue triangle stock to the leading edge. </div><div>
</div><div>Please post what this kit is and whether or not you have the build manual. </div>