The five pretotypes each answer a different question and helps us to define our objectives for the product
The carabiner should open the gate of a carabiner when minimum external force is applied.
The mechanism should cam of the carabiner without the application of rotational force.
The external sleeve should fit each and every size of carabiner available.
The spool holder for the carabiner should be easy and light to carry for climbers.
The remote sensed mechanism should get carabiner opened when operated from below.
The forced required to open the gate of the carabiner is 5N. Which is very low and can be easily opened by any normal human without disabilities
Rotational force required to cam off the carabiner is around 50N-m. Which is 10 times higher than the force to open the gate, so we are trying to design a system which does not require rotational force to cam off the gear.
The length bottom of carabiners to which the sleeve is attached does not vary much and variation of around 40mm across all sizes. Which indicate sleeves can be fit through various carabiners and users don't need to buy different sleeves for different carabiners.
The spool holder weights around 100gm and length of 30cm which is not heavy and easy to carry on the climber's waist
Remote sensing keys have a operating range of 5-20 metres. It will reduce the climber's effort to apply force but need a better mechanism which has high operation range of above 60 m.
Climbers need to carry extra rope other than climbing rope for retrieval of carabiners, but as they are light weight users didn't feel any problem in carrying the extra rope.
Bike Brake Mechanism was bulky to carry but would require less force to cam the carabiner off the anchor.
Spool Holder is additional item that need to be carried
Remote sensing mechanism would be expensive because of the electronic parts involved