Do you have the Pegas Scroll Saw or Pegas Chuck Head Set? If you ever have a problem with the clamping aside from the Set Screww and Thumb Screw with swivel, parts can be ordered. I do not stock these, but I can get them from Pegas. In fact, there are many parts available. There is a customer on Facebook where the Clamp Bracket actually split on a two-year-old saw. Any questions, I would be happy to help.
90.750-41D Clamp Bracket (for upper assembly)
90.750-36D Blade Chuck (for lower assembly)