This is the check spring to my longarm in two pieces. I found the piece on the (R) on my quilt top this afternoon. Luckily I had two replacement springs , unfortunately the one I tried to use for the first hour or so was defective!!!!
I spent all afternoon trying to replace this and ran into one issue after another. Finally, I think it's OK after quilting 2 additional blocks without problems but I was ready to pull my hair out. Let's just say the instructions didn't exactly match up to my machine!