Gravitrax spacer Fast and Spiral (3,4,5,6,8,10u)

I thought that it should be pretty easy to design spiral-mode gravitrax spacer, but yet I couldn't find any - so I designed one. It prints fast and uses as little filament as possible. So if You have 8 grams of filament and 15-20 minutes - give it a try :) (15 grams and 30 minutes for 10 unit piece)

How to print tips:

• Print it wit 0.8 line width (spiral mode of course) 
• Technically it is designed so it doesn't need any bottom layers, but for better adhesion you can set 3 bottom layers.
• If you want more - print them sequentially (mind collisions with X carriage)

Additional thoughts:

With 0.8 mm line width 3-unit piece weights 9 grams - so it is perfect for filament leftovers. The 10-unit part weights only 15 grams and prints in 30 minutes (layer height 0.4 and high flow nozzle). Probably I will improve this in the future - some extra indents to improve wall stiffness and modify latch part so it holds better, but as it is now it's fully functional and strong.