Frequently Asked Questions of the V5 Workcell

VEX V5 Workcell STEM Labs have been archived and are no longer being updated. As a result, they may not reflect current accessibility standards.

This article is to address frequently asked questions of the V5 Workcell, and offer troubleshooting techniques. View the video to walk you through these techniques. You can also find the techniques outlined throughout this article. 

This video is from VEX Professional Development Plus. Learn more about PD+.

Why is my V5 Workcell not moving accurately or shaking?

Comparison of VEX Smart Motors showing incorrect 5.5W motor and correct 11W motor labeled.

Ensure you are using the correct V5 Workcell Components in the correct build configuration.

Ensure you are using the 11W Smart Motor, NOT the 5.5W smaller motor. This error will cause the arm to shake.

VEX V5 Brain screen showing joint mastering values with pass indicators and table listing acceptable value ranges for each joint.

If your Workcell is not accurate or shaking, ensure your Mastering Values are up to date.

  • Old values will cause the arm to not be as accurate.
  • If a joint is failing, view the section ‘Are my potentiometers functioning correctly?’.

Expanded view of turntable components including ring gear, bearing, and mounting plate used for rotation.

If your values are within range, your Workcell may not be accurate/may shake because you need to lubricate your turntable.

An unlubricated turntable causes Joint 1 to have to account for extra resistance.

Workcell arm and base showing screw locations and turntable area highlighted where overtightening may cause resistance.Close up of the screws on the Turntable to indicate that they shouldn't be overtightened.

Ensure the screws on your Workcell are not overtightened.

  • Overtightened screws located on any components necessary to arm movement adds extra resistance.
  • If the four screws securing the turntable to the standoffs are too tight, there also may be more resistance.

Workcell arm diagram showing correct rubber band placement points used to support movement.

Ensure rubber bands are located at the three points, and are covered in the following steps of the Lab 1 Build Instructions:

  • Step 30
  • Step 47
  • Step 70

View this article for rubber band installation tips.

Cartoon map of the globe showing educators communicating internationally.

If you are still experiencing problems after trying these troubleshooting techniques, please contact VEX Support.

Are my potentiometers functioning correctly?

VEX V5 Brain screen showing joint mastering results with two joints failing and the two others passing.

The V5 Workcell uses potentiometers to know the position of the joints at all times.

If a potentiometer fails, this would cause the arm to not know its current physical location and may cause damage to the Workcell or the arm itself.

Before moving on, ensure all 3-wire cables are securely fastened to each other, where they are supposed to be. Operation of the arm may cause these wires to become unfastened with each other, resulting in a failure during the mastering process.

You can also view the Devices screen from the V5 Brain to check the 3-wire connections.

 

Metal mastering jig is shown being attached to the side of the arm to hold it still for consistent joint mastering.

If a joint failed during the Mastering Process, and to determine if your potentiometers are functioning correctly:

  • Run the “Arm Install” Blocks example. Note Acceptable passing ranges for each joint are:
    • Joint 1: 1600 - 2000
    • Joint 2: 1900 - 2400
    • Joint 3: 1700 - 2100
    • Joint 4: 200 - 650
  • Select “TARGET” if any potentiometers are not in range.
    • Once in range, select “HOLD” and carry on with the Arm Install.
  • If any potentiometer rotates endlessly, never stopping in range, repeat the first two bullets.
  • If any potentiometer still rotates endlessly, please contact VEX Support.

Why am I seeing no difference between Linear move and Joint move?

VEX V5 Workcell setup showing robotic arm mounted on base with controller and Brain connected.

Run through the solutions at the beginning of this article to ensure your Workcell is:

  • Built correctly
  • Mastered
  • Lubricated
  • Not overtightened
  • And contains rubber bands

VEX V5 Workcell setup showing a Y coordinate of 1.1 and a small arc being drawn by the arm on a piece of paper.VEX V5 Workcell setup showing a Y coordinate of -5.8 and a much larger arc being drawn by the arm on a piece of paper.

If you are running Lab 4, and seeing no difference between Linear move and Joint move, try increasing your “y” coordinate values.

By increasing the “y” coordinates from (-2 to 2) (top image on the left), to (-6 to 6) (bottom image on the left), the difference can be seen more easily.

Close up view of the three red Claw Gear Cranks in a row on the arm.

There is an easy trick to see which Block arm movement code your Workcell is performing. Watch the three red Claw Gear Cranks, they will remain stationary during Joint move, and will become active during Linear move.

Remember, this is due to the tool tip path determined and coded by you.

How do I install the rubber bands?

Workcell diagrams showing rubber bands installed to support arm movement similar to muscles.

The rubber bands on your V5 Workcell can be compared to the muscle in your arm. It offers support in lifting heavy objects, as well as it guides the arm safely through movements.

Step-by-step build instructions showing how to install rubber bands on the Workcell arm using proper placement and tools.

Installing the rubber bands can be confusing, but can be completed easily using this article.

For additional support or further questions, view VEX Professional Development Plus (PD+).

For more information, help, and tips, check out the many resources at VEX Professional Development Plus

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