Robot Parts and Materials - Answer Thread

[Sheldon]

My team came up with a design to use Silly Putty (http://www.amazon.com/Original-Silly.../dp/B000EOASEK) to pick up blocks. Is silly putty allowed? If the silly putty isn't allowed, what if my team made its own silly putty using glue, flower, and a few other materials? The silly putty does not leave any residue on the blocks or other field elements.

A; Silly Putty is considered a raw material and is allowed under rule <R04.b>. Remember that if pieces of the putty come off and stains the field or requires cleaing between matches then the referee has the option to penalize the team.

[Sheldon]

Product # 637118
ServoCity.com item; ball link part#(09.12.03) 6-32 x 1/4 in Swivel Ball Linkage (12 pack) Product # 585432

A: Rule R05.d> specifically allows for the use of COTS ball links. Therefore these parts are legal.

[Sheldon]

Dear GDC,

We were getting confused about what is the difference between a sheave and a pulley. We referenced this but still decided we need to ask the GDC what they mean since there are multiple definitions of a pulley.
http://en.wikipedia.org/wiki/Pulley
http://en.wikipedia.org/wiki/Sheave


Are these 3 Pulleys allowed?
McMaster-Carr Swivel Pulley
http://www.mcmaster.com/#3194T82


McMaster-Carr Double Pulley
http://www.mcmaster.com/#3099T23


McMaster-Carr Cheek Pulley
http://www.mcmaster.com/#3073T21


Or is only the sheave part allowed as a COTS and we have to make our own mountings to turn the sheaves into pulleys or pulleys into mounted pulleys depending on how pulleys are defined?
http://www.mcmaster.com/#rope-pulleys/=pazz8f

A: The term pulley and sheave may be used interchangeably when applied to FTC robots. All three examples described in this question are legal pulleys.

[Sheldon]

Hi,

Are these clamping hubs now allowed even if we don't use them with the associated wheel?

http://www.servocity.com/html/0_770__clamping_hubs.html

Thanks!

A: The intent of the rule is to allow teams to use COTS hubs to attach legal COTS wheels. It is not intended to open up the use of COTS hubs for other purposes. Therefore these hubs are not allowed unless used with a legal COTS wheel.

[Sheldon]

Can our team hang a wire or a chain from our robot to ground it to the tiles on the playing field?

A: No, grounding wires are not allowed. Experience has shown that grounding wires do not help and can actually cause more problems than it solves if those robots contact another bot..

[Sheldon]

Can we use screen door tension rollers as pulleys?

Prime-Line part no. B-522

http://prime-line-products.com/home4.wcs?nMenuid=0

A: Yes, rollers are allowed and may be used as pulleys.

[Sheldon]

Is paracord legal?

We believe that paracord (http://www.paracordstore.com/Black-P...cial_p_16.html) is legal per this rule:

<R06.a> "Rope, cord, cable, monofilament, etc. These can be made from natural (cotton, wool, etc.), polymers (nylon, polyester, etc.), or metal materials."

...but want to be sure because it is made of several strands of material wrapped in a braided outer sheath.

Thanks,
-7337 Robotium

A: Yes, Paracord is considered a rope and is legal per Rule <R06.a>

[Sheldon]

What kind of plastics are allowed? Is the following part allowed?

Clear Acrylic Sheet

http://www.lowes.com/pd_55844-1638-1...r|1&facetInfo=

A: Rule <R04.b> specifically states that plastics of any kind are allowed. Rule <R04.d> states that materials in the form of sheet are allowed. Since acrylics are a type of plastic, a sheet of acrylic is allowed.

[Sheldon]

Is braided fishing line legal?

We believe that braided fishing line (http://www.cabelas.com/product/Cabel...line&WTz_l=PPC) counts as a rope or cord and is legal per this rule:

<R06.a> "Rope, cord, cable, monofilament, etc. These can be made from natural (cotton, wool, etc.), polymers (nylon, polyester, etc.), or metal materials."

...but want to be sure because it is made of several strands of material braided together.

Thanks,
-7337 Robotium

A: Yes, braided fishing line falls under the definition of rope, cord, cable, monofilament, etc. listed in rule <R06.a>

[Sheldon]

Is metal tape (the type used for HVAC systems), allowed?

A: Yes, adhesive backed metal foil tape is considered a tape and is legal under rule <R06.f>