Robot Parts and Materials - Answer Thread

[Sheldon]

Is it permissible within the rules to put Tire 81.6 x 34 ZR Technic Straight Tread (http://www.bricklink.com/catalogItem.asp?P=2997) over stock Tetrix wheels even though this makes the wheels larger than 4"? I think that, since the wheels were purchased as Tetrix 4" wheels, they would be ok.

A: Per Rule <R01> all Lego parts are legal except for Duplo and the EV3. Since the Technic tire is a Lego part it is therefore legal to use. There are no restrictions on how the parts may be used providing no other rules are violated.

[Sheldon]

We were looking at using the VEX Winch & Pulley Kit (http://www.vexrobotics.com/vex/produ.../276-1546.html) and we were wondering if we can use all of the parts, or if we are restricted as to what parts we use. We were only needing to use the Winch Drum, Ratchet Gear, and Winch Pawl.

Thanks!

A: The parts described are all COTS and are illegal.

[Sheldon]

Hi Folks - We need to counter-weight the arm on our robot, and we are wondering if an Altoids tin is an acceptable material for use. We will fill it with the weights (most likely bolts and/or washers to achieve the correct weight), and seal the tin with duct tape. Will this be legal, or is the tin considered a COTS material and illegal?

Thanks!

Garry Wakely, Team 7090

A: No, an Altoids tin is a preformed metal COTS and is not allowed.

[Sheldon]

Are the following legal materials under rule <R04b>:

McMaster Carr Part #8920K115
http://www.mcmaster.com/#8920k115/=q82epv
1/4" Low Carbon Steel Rod

McMaster Carr Part #4416T91
http://www.mcmaster.com/#4416t91/=q82hsd
3/16" Easy to Machine Carbon Steel.

Thank You
FTC4318

A: Yes, steel rod is an allowed material.

[Sheldon]

Can our team add an adhesive (duct tape) to a 4" Lego Tire http://www.legoeducation.us/eng/prod...ix_wheels/2052

Adding the adhesive will make the tire a few mm larger than 4" .

A: The 4" diam. limit applies to the size of non-Tetrix and non-Lego wheels as purchased. Once purchased, teams may modifiy these wheels as they see fit, including adding material (such as duct tape, non-slip pad, etc.) to increase the diameter, assuming no other rules are violated.

[Sheldon]

We use spring steel to hang our robot and were wondering if the referee will have any problems with us using it?
It is bent down under a scoop at the start of the match and releases in autonomous.
When up, it is above 18 in so it should not come in contact with another robot.

We compete this weekend!

Thanks

A: Spring Steel is a legal raw material. Whether it is being used safely will be up to the inspector and referee. It is important that any stored energy device be operated safely and not pose a hazard to the FTAs, referees, etc.

[Sheldon]

Is plumber's chain (http://www.perfectionchain.com/plumberschain.html) an allowed material? The rules did not specify whether chain is counted as a rope, cable, ect. or if it is COTS.

A: Yes, plumbers chain is a legal material. It falls into the same category as rope and cable.

[Sheldon]

Is this material legal? It's a laminate of particle board with melamine on both sides. It is extruded materials, not post-machined, available in 49"X97" sheets from Home Depot and others. We believe it falls under <R04>b, c, and d. We'd like to use it as a mounting surface for controllers.

http://www.homedepot.com/p/Unbranded...1877/100070209

Thanks,

I2Robotics, FTC 6081.

A: This material is a post formed lamination of legal raw materials and is therefore considered a COTS. As such, it is not a legal material.

[Sheldon]

We want to use some counter weights for our block manipulator. Can we purchase pre-made lead fishing weights (similar to these http://www.cabelas.com/product/Fishi...3Bcat104685480) that we connect using string, twine, etc. or do we have to facbricate our own weights?

A: Pre-made weights are a COTS and are not allowed. Also, lead is considered a hazardouse material and is not allowed.

[Sheldon]

would we be able to "create" our own counter weights using various nuts, washers, string and/or duct tape?

A: Yes, Teams may use legal parts in anyway they choose, providing no other rules are violated. Therefore, using fasteners to create a counterweight is legal.