How to Fix the Sensor When Your Tufting Machine Keeps Running After Releasing the Trigger

A common issue with tufting machines is when the machine continues to run even after you release the trigger. This problem is usually caused by a malfunctioning or misaligned sensor that fails to detect the scissor’s position. We’ll explain how the sensor works, why this issue occurs, and provide a step-by-step solution to fix it.

Understanding the Role of the Sensor #

The sensor in a tufting machine monitors the movement of the scissor mechanism.

1. When the Scissor Retracts: As the scissor moves back into the machine, it makes contact with the sensor. This signals the machine to stop rotating.
2. When the Scissor Moves Outward: When the scissor extends outward, it releases the sensor, allowing the machine to move for the next cycle.

If the sensor fails, the machine may continue running even when the trigger is released.

Why Does This Issue Happen? #

Several factors can cause the sensor to malfunction, including:

• Misalignment so the sensor never makes contact.
• Yarn blocking the sensor.
• A loose or damaged sensor connection.

How to fix the sensor #

1. Turn Off the Machine #

Before you begin, turn off the tufting machine and unplug it to ensure safety while working on the machine.

2. Inspect the Sensor Area #

• Locate the sensor. It is positioned near the scissor mechanism on the right side of your tufting gun.
• Check for any visible yarn that might be blocking the sensor. Brush clean if needed.

3. Check the Alignment #

• Turn your tufting machine off. And manually move the gear so that your scissor comes out to see if it properly contacts the sensor when retracting.
• If it does not make contact when the scissor is pulled back, bent the metal of the sensor slightly. It should not make contact when the scissor is pushed out, and make contact when the scissor is all the way back into the machine. See the images above for a close up.

4. Test the Sensor #

• Plug the machine back in and turn it on.
• Pull the trigger shortly to observe if the sensor detects the contact and stops your tufting machine.
• If the issue persists, proceed to the next step.

6. Replace the Sensor (If Necessary) #

• If cleaning, alignment, and connection checks do not resolve the issue, the sensor may be faulty or the yellow cable could be broken. In this case, contact us.