Robot Parts and Materials - Answer Thread

[Sheldon]

The team was wondering if the following would be considered legal per the game rules?

Hub Spacers - http://www.servocity.com/html/hub_spacers.html

A: No, these Hub Spacers are a COTS and are not allowed.

[Sheldon]

Hello,

Are these http://www.amainhobbies.com/product_...r-Set-w-Pins-2 wheel adapters allowed, since we are thinking about using rc wheels and would need 17mm hex hubs? (Manual Part 1, R05 d (shaft adapters))



Thank you,

Team 358 The Gaulbots

A: No, these Wheel Adaptors are a COTS and are not legal per rule <R05>.

[Sheldon]

The Vex tire on the link below is a part of a COTS wheel.http://www.robotmarketplace.com/prod...-276-1489.html



However, if we were to do the following to this wheel would this be legal?


Option 1, Stretch this Vex tire on to a 3D printed wheel where the final wheel diameter will be greater than 4 inches.

Option 2, Stretch this Vex tire on to a legal 4 inch diameter wheel where the final diameter will be greater than 4 inches.

Thanks

A: COTS wheels and tires that are 4" dia. or less are legal parts. Teams may use legal parts in any manner they chose, providing no other rules are violated. If the Vex tire is 4" dia. or less ( the GDC cannot rule on the legality without measuring an actual tire) then both options are legal.

[Sheldon]

Based on the answers to several posts, it appears that VEX parts are allowed as long as they fall into specific categories (fasteners, 4" wheels, etc.). Can you confirm that VEX parts in these categories are not considered COTS? Second, can you tell us if the VEX rack and pinion system is allowable under the rules.

Additional question: Is fishing line considered a raw material or a COTS if used as part of a winch system?

A: The parts that are allowed by the rules are legal regardless of where they are purchased. Therefore fasteners (<R05.k>), 4" wheels (<R05.o>), and rack and pinon gears (<R05.g>) that are purchased from Vex are legal.

Fishing Line is legal per rule <R06.a>.

[Sheldon]

1.
<RG11> Game elements launched by Robots should not have a velocity greater than that required to reach a maximum of four (4) feet (1.2 meters) above the playing field surface, nor travel a horizontal distance greater than ten (10) feet (3 meters) from the point that the game element ends contact with the robot.

If game objects were launched at an angle, would this rule be judged on whether in their trajectory they remained below four feet and did not travel ten feet horizontally? For example, an object could be launched with a higher initial speed but at a lower angle to satisfy this rule.

2.
If one tetrix motor breaks (the leads pull out), could we combine it with another partially broken motor (front collar loose) to produce a single non-modified motor?

3.
Are VEX motor clutches legal? Or for that matter any commercial slip clutches?
http://www.vexrobotics.com/276-1098.html


Miniture slip clutches – http://www.mcmaster.com/#drive-clutches/=oxugmz


https://sdp-si.com/eStore/Catalog/Group/404

A1: At Hardware Inspection a robot will be tested to determine if it satisfies the criteria in Rule <RG11>. If, in any of the possible configurations (angle, motor power, etc.), an element is launched higher than 4' or longer than 10' then the robot will not be allowed to play.

A2: Rule <R08.w> expressly forbids the modifcation of motors. This includes the dis-assembly and re-assembly of a motor using identical parts.

A3: Slip clutches are not on the list of allowed COTS, therefore these parts are not legal.

[Sheldon]

<R05>g. Gears of any size and pitch, including non-circular gears such as rack, worm, bevel, etc.

We are seeking clarification of this rule as it applies to COTS parts. Are VEX parts considered COTS parts or are they considered illegal parts under 5.2.2?

Thanks

A: Rule <R05.g> allows for the use of gears of any size and pitch. There is no rule that stipulates where these gears can or cannot be purchased. Therefore, gears purchased from VEX are a legal part and may be used on a robot.

[Sheldon]

Per Post #39 on the Robot Parts and Materials - Answer Thread Hex Bars are considered legal.

The team is wondering the following parts would be considered legal under the same definition

1/2" Hex Shaft x 5" Long - http://www.andymark.com/product-p/am-0856.htm


3/8 inch diameter steel shaft w/ 3/32" keyway (am-2321) - http://www.andymark.com/product-p/am-2321.htm



Shaft Stock (3 options) - http://www.vexrobotics.com/vexpro/all/shaft-stock.html


D-Profile Shafts - http://www.mcmaster.com/#d-profile-precision-shafts/=oxz5g6

A1: Yes, this hex shaft is legal
A2: No, this shaft has been post machined to form the keyway and the threaded hole in the end.
A3: Yes, this hex shaft is legal
A4: Yes, D shafts are legal

[Sheldon]

Hello,

Are any of these gears allowed http://www.servocity.com/html/servo_mount_gears.html, given that gears are allowed (they have a pattern made in them to fit servo splines)?



Thank you,

Team 358 The Gaulbots

A: Gears of any type and pitch are a legal COTS, therefore these gears are legal. However, keep in mind that Rule <R08.w> prohibits the modification of any electrical part, including servos. This includes replacing the gears.

[Sheldon]

Is the use of a foam pad, cut to our desired size allowable? Something like one of these.

http://shop.hobbylobby.com/products/...y-foam-652370/


http://shop.hobbylobby.com/products/...0-grit-852582/


Thanks!

A: Yes, foam pads are a legal raw material. The pad with grit is allowed under rule <R07.e> which allows non-slip pads.

[Sheldon]

We found a sliding screen door roller pack and we were wondering if it is a legal part, for use as a pulley?

http://www.lowes.com/pd_55273-76018-...3042092&rpp=32

A: Yes, rollers are allowed.