Why don't you make use of all of that metal in the drive path? Assuming the FETs/Transistors are isolated devices the metal framework should provide a reasonable heatsink, without too much trouble. If the above are not isolated devices then you will have to put a mica strip(or modern equivalent) between the device and the metal. John -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body