From the beginning we have sought to install something other than a side tilt canopy (Sonex Design).
We have been trying to emulate the ASA swing back design with various minor changes.
The design that we are constructing is based heavily on the ASA swing back canopy design. We attempted to purchase the design from ASA but, despite the fact that the ��it��appears to be a bare bones design (mostly lacking instruction and detail), it is difficult to contact anyone at ASA to purchase the design. I would comment that it appears over priced as well, considering the low level of completion of documentation, based on what we've seen from those that were able to purchase the kit.
There are several web sites that provide some detail on the basic layout. The Sonex project by ��ynoth��is one of the more informative.
http://www.rynoth.com/wordpress/waiex/2015/03/10/general-fuselage-14-swing-back-canopy-completion/Tim has generated numerous detailed 2D simulations of the swing back action to try and understand the impact of different location points and lengths of the swing arms.
Being as impatient as I am, I started making parts to see how the details of mounting and operation could be resolved. These parts were basically an emulation of what Rynoth showed on his site. From the pictures he offers I could scale nearly all of the parts to a good approximation. An additional confirmation came from another experimental builder who had completed a flying Sonex with the ASA (purchased) design. Tim and I visited his hangar at 21D and were able to get a first hand view of the completed operation and test the difficulty of entering and exiting the cockpit. This gave us the confidence that the basic design provided reasonable access to the cockpit.
As a side note, the Sonex cockpit is a little tight in many respects. It is designed for two occupants but certainly on the ����version, it is minimal. One comment that I recall in discussions with flying Sonex builders is that, ��ou get used to stepping on the seat in order to slide into the cockpit.�� The concern was primarily focused on entering and exiting the cockpit and the possibility that the swing back configuration would make a difficult to access cockpit, even more challenging.
One note that was visible in the ASA design was the distance from the edge of the turtle deck to the back pivot point. This is just behind the second ��ormer��on the turtle deck structure.
The turtle deck pivot point defines a key parameter of the layout. Once this pivot point is located the basic motion of the canopy opening is ��ixed.��The other two key points of the operation are the back pivot point of the side swing arms and the attach point on the lower longeron bows on the canopy. Tim played with numerous locations for these points but after it is all said and done, there are very few options available, assuming the builder is a ��inimalist,��which I would strongly advocate as a guiding principle with any modification on the Sonex.
The back pivot point for the side arms is set at �€�elow the top of the longeron and approximately �€�orward of the back of the cockpit. The arm is held horizontal (parallel with the longeron). The forward attach point for the side arms is as far forward as is reasonable to avoid interference with the forward latches. This sets the maximum arm length from pivot to pivot of about 17�� The only other parameter is the vertical location of the attach pivot on the front of the side arms. I expended a lot of energy trying to resolve where this point should be. In the end, I lowered it from the ASA design and centered it on the vertical �€�eight of the square side bows on the canopy.
Raising or lowering this point did not impact the operation (as far as I can identify) and locating it where I did provide a simplified mechanism to attach the pivot to the bow without drilling any holes in the canopy bow (C-clamp). The photos should provide an explanation of how I tested the mechanism.