This page gives a general explaination on how a tufting gun works. This high level understanding of your gun is necessary for making any adjustments to your gun and understand why it might not work.
Two components at work
A tufting gun has two main operative components. The needle and the scissor/loop holder. These two components are motorized to move through the backing fabric. One component pushes the needle forward and the other one drives and pushes the scissors/ loophead forward.
The needle is the top component, the scissor or loophead is at the bottom of the needle. Both components can be adjusted seperately. When everything is in the right place, the components should be balanced out and be able to move freely without friction when you manually rotate it. This should always be the case before turning it on.
The different components move on a guardrail, it depends on your tufting gun what this looks like.
Opening and closing of the scissors
The scissor of you tufting gun needs to open and close. To make this happen your scissors have a part that sticks out.
When this part bumps in to a bar part of our gun, it will cause the scissors to open or close. So when this part breaks, which happens sometimes, your scissors will stop cutting.
When in use, the scissors travel forward in the open position and will close as soon as that part hits the bar.
When you want to change the pileheight, you will also need to adjust the position of this bar to make sure that your gun cuts the piles longer or shorter.