We have a new machine and our Ultra Pierce was missing a part when it was set up by the tech.  So it was never set up by Flow and we've been fighting with it ever since.  When our tech set it up he just capped the side where the Ultra Pierce connects.  What happens is this.  We don't have a problem with the piercing, in fact that works pretty good.  The problem is when we go from piercing to cutting.  The line from the garnet hopper down to the head seems to back up and garnet just stops flowing.  Once that happens any work piece just shatters.  We've tried several different metering disk all with the same results.  What should the jet on/off dwells be?  What should the Ultra Pierce dwells be?  Does the vacuum have to be shut off in the run menu before cutting or is the automatic setting O.K.?  BTW: Our maching is a Flow Mach 4c with a standard head.  Any help will be appreciated.  Thanks    Also,  I post the actual dwell settings once I get them from work.