[quote author=Mr. Ugly link=topic=3180.msg38850#msg38850 date=1206550027]
What did you guys use for the 20tpi lead screw?
Scavenged parts? Or did you pick up some acme threaded rod? Or something else?
Doing some kind of bearing support for the outboard end of the rod?
[/quote]Threaded rod for the lead screw through unistrut, with nylon bushings on either end. The mover is a small metal plate with screws welded to it that slides back and forth through the unistrut. One thing I noticed was when the motor was switching it is very quiet, no pauses, or clicks indicating to me that it is not hard on the motor, just a very smooth transition.
I'm very pleased with the whole hood arrangement in general, I'll be able to have 2 39w T5's along with 2 VHO's. My plan is to not run the halides for more than 6 hours a day, my tank gets enough sun as it is. Plus it's got nice recycled redwood trim made form the same material Mikey built his stand with, it's old barnwood.
BTW, I have a motor for you too Norman