Leaderboard

The instructions you posted that came with the tool seemed to be pretty good. They included the word chamfer in them when explaining how to prepare the tubing. At that point you should have done some research and found out what they were talking about before proceeding. Other forum members have made some good suggestions that included chamfering the tubing as well. If the main problem is still the tubing sliding in the clamp with the wing nuts are tightened down all the way, you could try removing a small amount of material by filing down the mating surfaces of the clamp to make the hole the tubing goes through slightly smaller. That would allow you to apply more clamping force to the tubing when the wingnuts are fully tightened. I don't know your skills or what tools you have so I'm not actually recommending doing this. I'm just telling you what I would do if I had the same problem.