I think it is a pulley that can slide along a rope without being damaged
friction hitch
The recommended prusik cord diameter for climbing applications is typically between 6mm and 8mm.
http://www.animatedknots.com/prusik/index.php
For a 1/2 inch rope, a prusik cord with a diameter of 6mm to 7mm is recommended for a secure and efficient grip.
A distel hitch is commonly used for tree climbing and arboriculture, providing a secure attachment point for ascending and descending. It is effective for vertical movements and can be adjusted easily. On the other hand, a prusik knot is versatile and can be used for ascending, descending, and self-rescue in climbing scenarios. It grips the rope tightly under tension but can slip if not properly tied. Overall, the distel hitch is more specialized for tree climbing, while the prusik knot is more versatile for various climbing situations.
There is a crankshaft pulley, alternator pulley, power steering pump pulley, AC pulley, idler pulley, tensioner pulley, etc.
a coumpound pulley is when there is a fixe pulley and movable pulley working together
a coumpound pulley is when there is a fixe pulley and movable pulley working together
The practice of climbing using only ropes (not actually climbing the curface of a rock) is Prussicking (or Prusiking). The knot is a Prusik Knot or Prusik Hitch. There are various sites on the internet where the technique and the knot it self is discussed and demonstrated.
pulley
Things that might cause a pulley to wobble: The pulley is bent. The shaft the pulley is on is bent. The pulley is mounted crooked.
The velocity ratio of a pulley system is the ratio of the rotational speed of the driving pulley to the driven pulley. It indicates how the speed of the driven pulley relates to the speed of the driving pulley. The formula is: Velocity Ratio = Diameter of driving pulley / Diameter of driven pulley.