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Official Q&A: VEXU 2022-2023: Spin Up

Usage Guidelines All Questions

VUR3 and VUR4 Differing Standards


Thank you for your clarification in Q&A 1269! We have another follow up question about VUR3 and VUR4. Again, here are the rules:


Fabricated Parts may be made using the following processes: a. Adding material, such as 3D printing. b. Removing material, such as cutting, drilling, or machining. c. Bending material, such as sheet metal breaking or thermoforming. d. Casting or molding material, such as injection molding or sand casting. e. Attaching materials to one another, such as welding or chemically bonding (e.g., epoxy).


Fabricated Parts must be made from raw materials. For the purpose of this rule, a “raw material” is any material that would not be considered a “pre-fabricated” part (i.e., has not undergone any of the fabrication techniques listed in VUR3). a. Standard raw material finishing processes, such as extrusion, heat treating, or anodizing, are not considered pre-fabrication.

To summarize these two rules, fabricated parts are additively or subtractively manufactured, formed, cast, or attached together. Raw materials are materials that have not undergone these processes.

The problem is, by a literal reading of the rules, basically nothing is a raw material. Materials such as 3D printer filament, plastic sheets, and metal billets, despite meeting the common sense definition of a raw material, have all undergone some of the manufacturing processes listed in VUR3 and should therefore not be considered raw materials by the written rule.

To solve this problem, the GDC has introduced 3 new standards to determine whether a part is considered a raw material. Sometimes the standard is the part's primary fabrication process, sometimes the standard is the part's finishing process, and sometimes the standard is the intention of the vendor who sold the part.

Each standard is fine on its own, but they are often in conflict with each other. When this happens, it's not clear when to apply which standard. We hope the GDC considers rewriting this rule in the future to make it less confusing. However, until then, we hope to gain some clarification by asking about a few specific parts. We have intentionally selected edge cases because we want to understand when to apply each standard.

1.) Are rubber bands that are not size 32 or 64 raw materials? Rubber bands are usually extruded and cut to length, which should make them raw materials by Q&A 1144, but they are also "intended to be used in the exact state in which it is (they are) sold & purchased," which should make them prefabricated by Q&A 1269.

If they are raw materials, how does that square with Q&A 1269, and if not, how does that square with Q&A 1144?

2.) Is gear stock a raw material? Many suppliers cast and heat treat their gear stock, and intend for it to be cut (subtractively manufactured) by the user, which should make it a raw material by Q&A 1235 and 1269. However, it seems like common sense that gear stock and normal gears are equally prefabricated / raw since the manufacturing processes and final geometry are very similar.

If gear stock is not a raw material, how does that square with Q&A 1235 and 1269?

3.) Is colored tape legal? In tape manufacturing, the backing and the glue of tape are attached together, which should make it a prefabricated part by VUR3 note e. Then the tape is dyed, which is a standard material finishing process and should make the tape a raw material by Q&A 1235. And, like an aluminum billet, tape is intended to be cut (subtractively manufactured) before use, so it should be a raw material (or at least shouldn't be disqualified from being a raw material) by Q&A 1269.

If colored tape is a raw material, how does that square with VUR3 note e? If not, how does that square with Q&A 1235?

Thank you for your time, and for your patience :) We know that these edge-cases are difficult to formalize rules around, and we appreciate your clarification and professionalism.

Answered by committee

Thank you for your questions.

1.) Are rubber bands that are not size 32 or 64 raw materials?

Acceptable usage of rubber bands is covered by rule <R7h>, unless you wish to fabricate your own rubber bands as permitted under rule <VUR3>.

2.) Is gear stock a raw material?

Commercial off-the-shelf gears are not allowed for use on VEX U Robots, which we believe is the question you’re actually asking here and the one we’re able to provide a definitive answer for.

Team-fabricated gears, machined from raw steel / aluminum round stock, would be legal.

3.) Is colored tape legal?

Acceptable usage of tape is covered by rules <R7f>and <R10>, unless you wish to fabricate your own tape as permitted under rule <VUR3>.

Generally speaking, we try to refrain from extending the logic of one rule into another. However, we believe that the red box note for rule <R11> is also pertinent to your string of questions regarding rules <VUR3> and <VUR4>, so we’ll extend it here: If a key component of your Robot’s design relies upon convincing an inspector that a specific material or part is “technically not prefabricated” or “technically a raw material,” it is probably outside of the spirit and intent of these rules.

Thank you for your patience. Edge cases are, as you’ve stated, difficult to formalize rules around.