Jim -- Just to add a note to what Ted said... As Ted said, the base should be pretty thick. One of the things about Lehmans is the need to adjust the leveling of the base once in a while. You will undoubtedly have leveling screws in the corners of the base nearest the mass. It is extremely sensitive to even slight turning of the leveling screws. The sturdier the base the easier leveling will be, and the wider the base the finer the adjustment that can be made. You may think this is overkill, but I'd try to find at least 1/2" thick aluminum, preferably 3/4" thick or more. And it should be at least 8 to 10" wide. The wider the better. If you have room, make it 12" wide. As Ted suggested, check surplus metal outlets for the aluminum plate. If you can't find a piece the right size, they might cut it for you for a few dollars more. Good luck on your project. Be sure to post any questions you have to the list, and let us know of your progress. Karl Cunningham La Mesa, CA. PSN Station #40 karlc@....... At 10:37 PM 12/29/1999 -0500, you wrote: >Gentlemen, > >My son and I are starting the process of building our first Lehman. I have >visited numerous PSN web pages, and would like to thank everyone who has >posted pictures and such relating to the construction. > >Would anyone out there care to supply me with just the basic dimensions of >the frame, boom, and base. I will be using Larry Cochrane's electronics, >and would just like to get a little help so that we can get this project off >the ground. _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>