[JVolkober]

How important is it to be accurate with marking the centerline? The centerline is used to get the canopy latch hole in the proper location and appears to be essential for getting the frame square in the canopy.

I have measured center points at five locations multiple times using a cloth measuring tape. No stretching. I am measuring from the lowest mold line. For each location I get slightly different measurements. By picking a point that "averages" the multiple points, I will be close, but is that good enough?
My canopy came with markings that appear to indicate the center locations at the forward and rear end. Are these reliable indicators of the center point at those locations?

The canopy is for a 9A.

 

[sportpilot]

RV9

dont know what plane your building, but I built a 9A and what it boils down to is the low edge of the canopy where you cut away to fit along the bottom rail is one thing, and the line down the center your going to drill into the frame is another. the true proof is when your canopy is cut along the bottom edge sufficient to mate to the frame, then the center will be where you will drill the rivet holes into the center frrame member. Im not to sure it matters where you make a measurement. be careful not to cut away to much along the bottom edge, thats critical for edge distance of the screws.