Jim, I am using threaded rod on my two Lehmans. One is brass the other is stainless steel (stainless steel is non-magnetic). I drilled and tapped home-cast lead weights for both. This makes it easy to position the weights on the boom. I locked the weights in place with stainless steel nuts and washers. I use two weights either side of the magnet so that the balance point of the boom assembly, when suspended vertically by the support wire, is close to the magnet itself. Regards, Martin Brewer, Bermuda -----Original Message----- From: JIM MARTIN [SMTP:jdmartin@............... Sent: Friday, December 31, 1999 5:42 PM To: PSN-L@.............. Subject: Lehman design questions To anyone who wishes to help:Has anyone used a piece of threaded rod for the boom, or is it better to stick with an aluminum dowel, say 1/2" in dia. ? Jim Martin New Haven, Indiana _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L) _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>