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

Usage Guidelines All Questions

<R11> Commodity Hardware


GOTEM
4-Jun-2022

<R11> states

Certain non-VEX fasteners are allowed. Robots may use the following commercially available hardware:

  • a. #4, #6, #8, M3, M3.5, or M4 screws up to 2.5” (63.5mm) long (nominal).
  • b. Any commercially available nut, washer, standoff, and / or non-threaded spacer up to 2.5” (63.5mm) long which fits these screws.

And the red box underneath states that

The intent of the rule is to allow Teams to purchase their own commodity hardware without introducing additional functionality not found in standard VEX equipment.

Robosource sells these screws for VRC teams that include a shoulder that perfectly fits the holes in VEX structure. https://www.robosource.net/robot-parts/screws-hardware/shoulder-screws/regular-shoulder-screws/479-shoulder-screws-1000-piece-variety-pack .VEX sells a now-discontinued shoulder screw of one (very small) specific size. The shoulders on the robosource screws are very helpful for creating joints and making sure that structure is mounted at square angles. The VEX-sold shoulder screws are quite frankly useless in this regard.

McMaster-Carr sells these nylon screws that function perfectly with VEX hardware. https://www.mcmaster.com/nylon-screws/nylon-pan-head-phillips-screws-10/thread-size~8-32/. Nylon screws can be very useful for saving weight on mechanisms such as a lift where the less massive something is the better it performs.

McMaster-Carr also sells these lock washers. https://www.mcmaster.com/washers/washers/external-tooth-lock-washers-9/for-screw-size~no-8/. These certainly introduce functionality not found on VEX washers, however the VEX-sold keps nuts contain one of these lock washers each which can be removed, however tediously.

My questions are the following

  1. Are commercially available 8-32 screws up to 2.5” in length with an added shoulder legal for use?

  2. Are commercially available 8-32 screws up to 2.5” in length made out of nylon legal for use?

  3. Are commercially available 8-32 screws up to 2.5” in length made out of aluminum legal for use?

  4. Are commercially available lock washers legal for VRC use, considering that they already exist legally on vex-sold keps nuts? If not, if a team were to remove lock washers from keps nuts for use on their robot, what is the minimum amount of documentation they would be required to provide to prove the manner in which they acquired the lock washers?

  5. What is the maximum outer diameter for a washer or spacer that could reasonably fall under this rule? Would a nylon spacer with a 2” outer diameter be legal on a VRC robot, provided it was being used for spacer-like activities? What if it was used in a different way?

Thank you for your time.

Answered by committee

The June 28th Game Manual update will include revisions to R11 that should help to clarify this question. If it is still unclear after that release, please feel free to rephrase and re-submit at that time.