Sli3DR is not a Delta based printer, rather it's based on an intriguing 'unnamed mechanism' that was floating around on the RepRap Forum and G+ last y...ear. Billy Zelsnack Identified it as used in a very old (Rikadenki) Pen Plotter design.
A few people have tried it out for 3D printing using off the shelf mechanical parts, I wanted to make it with 3D printed parts and Spectra Line based on this mechanism.
Tim Rastall was also designing a Super-big Tantillus called the Ingentis around the same time. I printed an early set of Ingentis parts, but after seeing the above mechanism I just had to design a printer based on it. I did borrow the style of Tim's Z-Axis arms, (Thanks Tim) everything else needed to be designed and had to be able to be scaled up or down.
Edit - This bit's updated for correct back credit of bringing the mechanism to the attention of the RepRap and 3D printing community - David Moorhouse over on G+ showed a cable bot design 1st November 2013, see here - https://plus.google.com/104904818050178236499/posts/WpzzVuULM2z
This License is not greatly restrictive at all, so please don't forget to attribute my work
and acknowledge.
If you decide to print and sell these or make further changes,
improvements or additions, that's great! I want you to do that !
I hope this work has been of some use to you,
if you wish to say hello or donate towards further developments please see my Blog
here - www.richrap.blogspot.com