Answered: 3D-Printed VEXnet Key Holder

I have about a dozen VEXnet keys where the metal-to-plastic connection is quite sloppy and this sloppiness is highly likely the cause for some connectivity problems during the events. :mad:

In an effort to reduce connectivity issues caused by the metal-to-plastic connection on the VEXnet USB Key, could we 3D print a “key holder” that would provide protection for this expensive device which is critical to the operation of the robot. It would not serve as a functional purpose for lifting, driving, or other mechanics, but would allow teams to mount their key in a non-metallic case to protect it from the rigors of competition. It would also keep it from getting removed in an arc (damaging) as opposed to linearly (safely), thus extending the life of the components.

If you look at the different designs of the slot for the VEXnet key in both the Joystick and the Microcontroller, the Joystick has plastic “ribs” that only allow the VEXnet keys to be inserted and removed linearly, which protects it from students and how rough they can be on the equipment. The Microcontroller doesn’t have those “ribs” to keep students from pulling them out in an arc and, in the process, damaging the metal-to-plastic connection. I would argue that most of the damaged VEXnet keys I have are from the removal by students in the Microcontroller, not the Joystick.

This type of usage of a non VEX part is not permitted by the rules. If you’re for a way to safely mount your VEXnet key, especially in terms of removal, please consider the special allowance in <R7j>. I’ve quoted the rule below:

What if the 3D printed VEXnet key “holder” was simply a component of the “cable management”?

Rule R7 l. Items used solely for the purpose of bundling or wrapping of 2-wire, 3-wire, 4-wire cables, and pneumatic tubing, for the purposes of **protection, organization, or management **are allowed. This includes but is not limited to electrical tape, cable carrier, cable track, etc. Note: it is up to inspectors to determine whether a component is serving a function beyond protecting and managing cables. And rule R7 j. A USB extension cable may be used for the sole purpose of remote mounting of a VEXnet key.

If the key holder is designed to protect the VEXnet key from damage and manage the extension cable at the same time, wouldn’t that fulfill the components of both rules? Yes, I see the Note: that makes it up to the inspectors to determine whether a component is serving a function beyond protecting and managing cables.

This would be not allowed for two reasons.

  1. The holder is serving a function beyond cable management.
  2. The use of 3D printed devices for cable management is not permitted. For more information see the following Q&A entries: