You may have something loose. Perhaps it's a wire, but the more likely cause is a loose battery. It takes a lot for li-ion batteries to come loose, but it can happen. If it happens, look at the batteries right away. See if they came loose. If they are loose, then get some velcro, electrical tape, or rubber bands to secure the batteries. Maybe some bubble wrap to go in between the battery pack and hilt will also help.
If it's not the batteries, then I'd contact US.
info@ultrasabers.comOkay I'm going to do some more testing today, yesterday I checked to see if the batteriws were loose but they didn't seem like it, I'll try and find some bubble wrap or something of the like to wrap the battery pack with, and I've got a bag full of rubber bands I'll wrap one or two around it and see where that gets me, I'd really rather not send it in seeing as how I've only had it 3-4 days but if it's a must then I will, I could probably fix it myself if I had to but I'm not sure how safe that is