For those who are skeptical about propellers - Team 2526

[ChuckDickerson]

Originally Posted by Russ Beavis

To any teams that will be using propellers on their robot, be prepared for serious scrutiny from your robot inspectors. I'm still developing the inspector training materials for this particular design element and I'm leaning towards placing a lot of the burden of safety verification on the teams.

Be prepared to defend your design. I would strongly encourage you to bring a "standard finger" to demonstrate general protection.

I would strongly encourage you to calculate the amount of energy stored in your propeller(s) at max speed and determine whether that energy is sufficient to punch through your enclosure. For example, how much energy is required to "rip" a steel wire of diameter X? Maybe you can find such destructive limits on online materials databases.

Bring plenty of documentation to support your design.

Good Luck and BE SAFE!
Russ Beavis
Chief Inspector

Russ,

Thank you very much for addressing the safety issue of propellers here on CD as a warning. I have two questions though:

1) Will the "inspector training materials for this particular design element" be officially released on the FIRST website so that teams will know exactly what they need to be prepared for?

2) Will the "standard finger" be defined? Something like a 3/4"D x 3"L wooden dowel or something? If left to the teams to define I would expect as many different definitions of a "standard finger" as there will be propeller designs. Actually it seems like this should be something that the inspectors provide at inspection rather than the teams if it is to become a "standard" similar to the sizing box or scale.

I ask because the safety considerations for propellers should be taken seriously but the only defined requirements that teams have access to at the current time is the Inspection Checklist. Maybe a section could be added to the checklist covering minimum propeller safety requirements?