Why don't you put a tank (half filled) of water on each side of the Lehman and use two little aquarium pumps to pump the water back and forth between them, thus shifting the floor slightly. You could then adjust the flow rate with a throttle valve to get the desired hysterisis, since you would want it to pump more water than that which was simply required to move off the "stops". Each one simply pumps from the bottom into the top of the other. A pair of chemical tanks for water conditioners would be cheap, have tight-fitting lids to eliminate evaporation, and, at 15 gal would weigh up to 120 lbs, which should be more than enough to do the job. No fancy circuitry, machining or vibrations to deal with. In addition, they would guard your sensitive detector from stray cosmic rays. Tom On Tue, 19 Nov 2002 19:03:50 -0700 "Dewayne Hill"writes: I want to make my Lehman self leveling as it is in the crawl space and I'm getting to the age I hate crawling on my hands and knees as I did when I was 3. What I have in mind, but need help with is to connect a common wire to the base plate which in turn will also put the same electrical potential on the boom as my Lehman is all metal. I want to insulate my boom stops from the base plate and connect a plus voltage to it and a minus voltage to the other stop. When the boom touches one of the stops it will complete a circuit that will activate a DC motor that in turn will driver one of my leveling screws a preset amount of rotations or for X amount of time. What I need help with is a circuit to control the motor. I have read that a step motor can have a controller that will control the number of rotations or steps and then stop. Can anyone Help? Regards, Why don't you put a tank (half filled) of water on each side of the=20 Lehmanand use two little aquarium pumps to pump the water back and forth=20 betweenthem, thus shifting the floor slightly. You could then adjust the flow= rate=20 witha throttle valve to get the desired hysterisis, since you would want = it to=20 pumpmore water than that which was simply required to move off the "stops"= ..=20 Eachone simply pumps from the bottom into the top of the other. A pair of= =20 chemicaltanks for water conditioners would be cheap, have tight-fitting lids = to=20 eliminateevaporation, and, at 15 gal would weigh up to 120 lbs, which should be= =20 morethan enough to do the job. No fancy circuitry, machining or = vibrations=20 to deal with.In addition, they would guard your sensitive detector from stray = cosmic=20 rays.TomOn Tue, 19 Nov 2002 19:03:50 -0700 "Dewayne Hill" <n0ssy@.........> writes:I want to make my Lehman self leveling as it is in the crawl space and= I'm=20 getting to the age I hate
crawling on my hands and knees as I did when I was 3.
What I have in mind, but need help with is to connect a common wire to= the=20 base plate which in turn
will also put the same electrical potential on the boom as my Lehman = is all=20 metal. I want to insulate
my boom stops from the base plate and connect a plus voltage to it and= a=20 minus voltage to the other
stop. When the boom touches one of the stops it will complete a = circuit=20 that will activate a DC motor that
in turn will driver one of my leveling screws a preset amount of = rotations=20 or for X amount of time.
What I need help with is a circuit to control the motor. I have read = that a=20 step motor can have a controller
that will control the number of rotations or steps and then stop.
Can anyone Help?
Regards,
Dewayne Hill