Robot Parts and Materials - Answer Thread

[Sheldon]

on 10-04-2013, 04:48 PM GDC Block Buster answered a question saying that teams may use allowable materials to build wheels larger then 4" in diameter.

Rule 5.2.2 <R05> o. states:
Wheels of any type up to 4” diameter (as measured at the outer surface of the tread). Wheels that have exposed
features likely to cause damage to field and/or game elements are not allowed. Wheels are considered to be the
total of the rim (the plastic or other material on the inside), the tire (the rubber or other material on the
outside), and the manufacturer provided wheel hub used to mount the wheel to an axle. Individual components
of a legal wheel assembly can be used on the robot (as long as wheel and hub are 4” diameter or less).

So, would it be in within the rules to take a cots wheel & hub that are 4" or less in diameter and add our own "tire" made from a legal raw material to end up with a tire-wheel-hub assembly with a diameter greater than 4"?

A: Yes, you may modify a legal COTS wheel with a custom tread and make it larger than 4" diameter.

[Sheldon]

Are we allowed to shorten the shafts on 12 volt DC motors?

A: No, rule <R09.w> specifically prohibts altering motors in any way.

[Sheldon]

Hello,
Would the following be considered a bearing and/or a turntable and be allowed under rule <R05??

http://www.amazon.com/gp/product/B00...productDetails

Thanks,
Team 5938

A: Yes, the Lazy Susan Turntable is a turntable and is a legal COTS.

[Sheldon]

Is pegboard permitted as a raw material? It is readily available as a lumber/hardwood product but has been "processed" to include the holes. Thank you!

A: Pegboard is a lumber product that has been post processed, therefore it is a COTS. Since it is not on the list of allowed COTS parts this makes pegboard an illegal material.

[Sheldon]

We are planning on using a rope / hook. Our first hook is from Home Depot, pre-bent into a curve with a hole at the bottom. I'm just checking to see if this is legal, and to see how far COTS goes -- it's not much more that we would do ourselves. Thanks

A: This hook is a COTS and since it is not on the list of allowed COTS it is not a legal part.

[Sheldon]

Team 7079 would like to clarify whether nylon webbing (used as a strap/tie down) falls under the raw material or COTS category, and would therefore be an allowable material.

A similar product can be found here: (we will be using the strap without the ratchet) http://www.homedepot.com/p/Classic-A...9#.UnbBfBbam2w


Home Depot: Model # 52-030-010401-00 Internet # 203028359

So as final resolution our questions are: Does Nylon Webbing Strap fall under Commercial Off The Shelf Products or raw materials. And Do the rules permit it's use in FTC Block Party Games.

Thanks,
Team 7079 Faltech

A: Nylon webbing is an allowed raw material but any fittings, hooks, ratchet etc. are not allowed.

[Sheldon]

Are the following 8020 parts considered legal per Rules <R05.a> and <R05.n>

Please refer to the 8020 interactive catalog - http://www.8020.net/interactive-catalog.html

1. Double Flange Linear Bearings - Part #6725 - Pages 500-501
2. Roller Wheels - Part #2281 - Pages 398-399
3. Roller Wheel Brackets - Part # 2750 - Pages 398-399

A: Yes, these parts are considered a linear slide and are legal per rule <R05.a>

[Sheldon]

Hi -

We made a crate made of plastic. TETRIX® L Brackets (W739062) are used to join vertical and horizontal sides of the crate with TETRIX® Socket Head Cap Screws. L Bracket is inside the crate but screw head is outside the crate. Please see the attached picture.

Questions:
1. Will the screw head outside crate fail the inspection (RG3a&b or any other). Please note - crate may touch the playfield.
2. If it fails the inspection, how do we correct this? Can we put tape to cover the head?
3. Is following plastic allowed (Clear Acrylic)?
http://www.lowes.com/pd_55844-1638-1...3D1&facetInfo=

Thanks,

A: Rules <RG03.a and b> are designed to disallow mechanisms that could harm the field or other robots, such as sharp plows that could dig up the tile floor, or the use of gears as wheels to gain extra traction. It is very common for screw heads to contact the playing surface as well as other robots, they are not considered dangerous or hazardous mechanisms. Your use of the screw head is legal.

[Sheldon]

Per Post #66 in the FTC Block Party! The Robot - Inspection and Build Rules - Robot Parts and Materials - Answer Thread



The team is wondering if this could be generalized to

You can modify a legal part including allowed COTS parts, provided no other rules are violated.

A: Yes, you may modify legal COTS parts providing no other rules are violated.

[Sheldon]

Can we use a Chimney Brush like the ones found here: http://www.lowes.com/Fireplaces-Stov.../N-1z0x13w/pl#!

A: A chimney brush is assembled from a variety of metal and plastic parts and is considered a COTS part. Since brushes are not on the list of allowed COTS parts they are not a legal parts.