PSN-L Email List Message

Subject: Re: Help with self leveling Lehman
From: Thomas W Leiper twleiper@........
Date: Wed, 20 Nov 2002 00:54:38 -0500


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 Lehman
and use two little aquarium pumps to pump the water back and forth=20 between
them, thus shifting the floor slightly. You could then adjust the flow= rate=20 with
a throttle valve to get the desired hysterisis, since you would want = it to=20 pump
more water than that which was simply required to move off the "stops"= ..=20 Each
one simply pumps from the bottom into the top of the other. A pair of= =20 chemical
tanks for water conditioners would be cheap, have tight-fitting lids = to=20 eliminate
evaporation, and, at 15 gal would weigh up to 120 lbs, which should be= =20 more
than 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.
 
Tom
 
On 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

 

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