Looking for advice from veteran teams on this

[Rob]

Hello,

We posted the following question on the Q&A:

"Would burn wire, a small guage wire that disenegrates when current is applied to it be allowed? A few inches would be used for the sole purpose of ramp release and would be replaced each match. The part passes the flow chart as long as it is considered safe."

and got the following response:

"If it is copper wire, it is impossible to answer this question without a complete, detailed inspection of the specific implementation. We must ask you to use your best engineering judgement to assess whether your particular application poses a realistic potential for damage to the field or field equipment. If there is any question, you may want to ask one of the experienced veteran teams in your area to consult with you to help you determine the best course of action."

Link to the actual post: http://forums.usfirst.org/showthread.php?t=4935

So my question is: Do veteran teams out there think this poses a risk to the field of field equipment?

My initial reaction is no it does not because we will shield the wire with plastic and it will never contact any field element unless our robot suffers catastrophic damage, but as the GDC suggests, we are looking for guidance from experienced veteran teams.

Thanks for any input on this topic.

RAZ

[Al Skierkiewicz]

As an inspector, I would rule that this is not allowed. It is not a matter of just merely damaging the field, there are other considerations such as insulation and fallout from the burn process for other robots. You have so many other devices at your disposal for this application I am sure you can come up with a very ineteresting design.
For me, the flow chart investigation stops at the first block.

[MikeDubreuil]

I would like to see a data sheet. However, based on how you described it this is my answer:

Depends on the inspector. You did not get an official answer from FIRST about your particular application. Therefore, it will be how the lead robot inspector feels about your application of the burn wire. We can't be used as a source when dealing with the inspector.

• Your application violates the intent of custom electronic circuitry <R60>. Although that does not preclude its use.
• Your application sort of violates R61 and R63.
• There is a big question about an electrical component whose design it is to become extremely hot to the point of failure would be considered safe on the parts use flow chart.

In other words, you're on thin ice. If I were you I would redesign.

[Wayne Doenges]

As an inspector I will probably not alow this either.
If I understand it right, you are using a wire similar to what they use in model rocketry. When a current is applied, the wire gets hot and separates.
My concern is when insulation is heated it may give off a toxic vapor even though it would be a small amount.

[Elgin Clock]

Originally Posted by MikeDubreuil

• There is a big question about an electrical component whose design it is to become extremely hot to the point of failure would be considered safe on the parts use flow chart.

Isn't that the point of a fuse and breaker, and these are required components?

Originally Posted by MikeDubreuil

In other words, you're on thin ice. If I were you I would redesign.

I would tend to agree with that statement 100%.
-If I were your inspector, I would want to see a sample run of the item before I passed it.
-If I were the team who heard that response from an inspector, I would just ditch it to save myself some nightmares.

Your call though.
I would redesign it using something else, but bring it along and show the LEAD inspector. It may be something to consider, or at least bring to FIRST's attention for future usage rulings.

[sanddrag]

We tired to use nichrome wire in 2003 to burn through a string to release suction cups. Worked great. We told them we would have it in a fully contained and sealed box so no smoke would be released. They wouldn't allow it.

I'd say figure out something else.