I was happy with airbox cover shape and the idea was to keep the stock airbox cover (I bought aftermarket carbon fiber airbox cover with air ducts after all) and design new tail. This is how basically Fredy ee Buell top monocoque portion was made and it looks fantastic.
Once I had figured out best side view profile for the tail section on preliminary Paint sketches I started surface modeling in Solid Works. The picture below shows the CAD design mess I developed in process of sculpting the tail shape.
One of the main reason of designing in CAD program is you can play with different shapes and forms without mocking this up on real motorcycle, you can check fitments of the internal components and so on.
But for me on this stage the most important part was to design the tail shape which will look good and match the motorcycle appearance from different points of view and from different perspectives. I saw many motorcycles with nice looking shape from one angle, but once you start walking around it you figure out that it does not look so pleasant from another angle. And again the good thing about CAD design you can see how your shape looks from different perspectives. If you don't like it you can tweak it until you will be happy wit result. Fortunately there are 3D Printing technologies and materials which allow you to print almost any shape with crazy mechanical features with no limitations, strong and heat resistant, with nice surface finish, with no post processing required and I decided that the easiest and the most reasonable way to build the tail using such 3D printing technology, HP Multi Jet Fusion 3D printer particularly with Nylon12 material impregnated with black pigment for black color. So I was not limited in tail shape and features and I designed it the way it looks the best because of there was not any difficulty in producing any shape with any mechanical features.
I developed the tail shape also considering there will be some components hidden inside like rear shock absorber remote gas reservoir, alarm system components, tail lights wiring, tail lock and support frame of course. It also should accommodate seat foam padding glued on top, licence plate bracket with licence plate light on bottom and tail LED stripe tail light combined with turn signals.
After all woes with tail internal components allocation process I came up with pretty dense and slim packing of everything inside of this thin tail.
The tail slides on and off the CNC machined subframe. The subframe cares Scorpio alarm system electronics, rear shock absorber gas can and wire harness for the tail. It also has key lock from original Buell XB seat I implemented in the new tail so you can slide it on and lock it.
As you can see the tail slides off the subframe with tail light, license plate light and licence plate itself. And you may ask, how do you connect this lights in the separate tail to the motorcycle harness without wires? Well, I found the solution - I mounded spring loaded pogo-pins in the tail and they engage with the electrical contact padding on the subframe making complete circuit to control the tail lights.
So 4 pins provides:
-Run light, Brake light and licence plate light "+" wire
-Left turn signal "+" wire
-Right turn signal "+" wire
Run light, Brake light and licence plate light "+" wire provides low and high voltage to maintain Run and Stop LED light on the same LEDs array. And the same wire feeds the license plate light. The reason I use 4 wires instead of 5 wires is because of I have so limited space in the tail that I can not mount one more pin and route one more wire in the tail.
And you may say, hey, your licence plate light will flicker and change brightness with stop signal light once you will press the brake. NO, it will not! Because of my tail light has custom build PCB controller board to maintain constant voltage on the licences plate LEDs array regardless of it gains run signal voltage or stop signal voltage. A friend of mine is electrical engineer and he designed this custom PCB controller board with LEDs array exclusively for this project, so this awesome feature would not be possible without him. I will share the details about it later.