Baden Powel Man Lifter
I have used 4 mm carbon. I modified the original plan for to use 100 cm carbon for both spine and strurt. All the spars are 100 cm. It is not as stable as I expect but still trying te bridle. I could not succeed with the bridle points of the original plan and changed them as you can see in the drawing below.
I will build a bigger one for my KAP trials. Even this small one gives a strong pull.