Fixture clamps - video

[Jon]

Fixture clamps. By The Hobby Machinist NZ. 40:05 video:

[mansworld]

The original modular welding clamps have a collar near the bottom to stop the bar from passing all the way through the hole. The problem with your design is that whence you set up your work piece and start welding, you have no way of telling if your clamps have shifted up or down in the hole.