Set up the bell crank with the short arm vertical at the bottom 6 o’clock position. Run a string from the bellcrank cable hole to the #5 rib to represent the cable. The cable position should be about 1-1/2 inches above the spar web at #5 and in far enough so that the cable would pass through without notching any ribs between No.5 and the bellcrank.
Back to the table: To set the height of the holes above rear spar web: (notice every measurement refers to spar web or the .032 channel) At the edge of the table representing rib #1, mark the fairlead center height above the spar web (Make sure to remember to add for splice plates to give the correct working height.) Go to Rib 5 and measure up to the centre of your intended hole from the spar web. Back to the table and mark this height from the edge of the table on rib line 5. Now take a straight edge and draw a line from your height on rib #1 to rib #5. Each intersection of the line at each rib will give the centre height of the hole in that rib from the spar web.
Now setting distance in from the bottomside or underside of wing. The edge of the table now represents the flat bottomside of the ribs/underside of wing: Measure horizontal to the centre of the No.1 rib fair lead from the bottom side of the wing rib. It is fairly flat and easy to measure from. Keep the measurements level. Mark that distance up from the corner of the table at rib #1 with a different color (red). Measure in horizontal from the bottomside of the rib to the centre of the hole at 5 and put that red mark up from the edge of the table. Draw a redline from the mark at #1 to #5. That will give all the intersecting points and horizontal distances measuring in the bottomside of the wing. Measure the table at each rib line from the edge of the table to the intersection at each rib. Carry that measurement from the flat of the rib along the parallel line and mark it with a vertical tick and that gives hole center location.
