Blake Sessions discovered a way of compacting and balancing the ancient Chinese Windlass mechanism as a cost effective way of efficiently converting rotary motion to linear motion. This compacted windlass approach is known as the "conical differential drive".

As a proof of concept, a 31 inch actuator was made utilizing a 1mm steel cable that could pull 45lbs over 100mm in an astounding 1.8 seconds. While weighing 300 grams. However, due to its wide cross-sectional area, its rated Pounds per Square inch rating resides at 3.17, Rise Robotics's current means of measuring its ultimate performance. Its application demonstration was to assist Hesham's lift project an affiliate of Rise Robotics. As with any new innovation, failure modes are not entirely understood. This design would fail imminently if the lines were ever tangled by improper handling. 

Operating load
Cyclone reduction (not incl. Gears)
stroke
stroke time (sec)
Speed
Mtbf - “life”
failure modes
weight
efficiency
height
width
length
contraction ratio
psi
push/pull

45 lbs
14
105.5 mm
1.8 sec
59 mm/s
10
immediate entanglement
0.7 lbs
70 %
1.8 inches
7.00 inches
31.6 inches
15.1 %
3.17
Pull Only


THE NUVU MINI CYCLONE 1.1 ROPE PISTON

September to October 02013