Hello Meredith, Angel and others, Thank you for your recommendations. Yes, I use the original Lehman knife edge design, since its quite unstable, I am gonna try to use Angel's version. Tomorrow I will check a local machine tool store, to find out if they have some surplus materials. I am thinking of a 20-30 cm wide frame, to get it as stable as possible. I will let you know more tomorrow. Thank you for your help. Best regards, Marchal van Lare _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>