I am trying to laser mark SS stemmed wine glasses. They keep jumping off of the rotary when I frame it up. I am thinking maybe the stemmed end is too light?? I have tried to attach a little weight to that end, but it didn't solve my problem. I also slowed down the test speed all the way to 2mm/sec. Any ideas?? This is very new to me. We are just starting out with this and learning as we go.