DIY 3.5 bar FPR

Here is the 3.0 bar regulator

Inserted into fitting in vise with socket over the nipple end, ready to SQUEEZE.
A slow and steady supply of compressed air is passed through the regulator.  The regulator will show it's working pressure on the gauge in the line.  Squeeze until the desired pressure is reached and voila! a 3.5bar (or higher) regulator has been formed.