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Hi Richard,
Thanks for the information. I was told that if I plumbed
the lines such that the pump fed the center of the line going to each cylinder
that the pressures would be pretty much equal. So I tried that and it
appears to work just fine - any drop in pressure due to friction in the lines is
apparently equal to both cylinders. It took a bit more hose to do it
that way - but the hose was cheaper than an equalizer valve. Tracy
Crook indicated that is what he had to do for a similar door - feed the
cylinders from a "T" at the mid point between both.
Yes, my operating control is a momentary push button also -
meaning once you take your finger off it the motor and motion stop - opening or
closing. I also have a keyed battery switch on my battery box - so when
the operation is finished I can remove it and prevent anybody from intentionally
or unintentionally operating the door - without first inserting the key and
turning the power on.
I am putting on limit switches such that my system will not
operate unless all locks are first opened and then will have one to prevent the
door from opening beyond a certain point (85 deg?).
Good to hear you have had 7 years with no problem
operation
Ed
----- Original Message -----
Sent: Monday, August 14, 2006 10:48
AM
Subject: [FlyRotary] Re: Emailing:
DoorOpenLside.jpg
Hi Ed,
I have a similar door on my hanger, it is 30ft wide and made of steel
sq-tubing. It is lifted by two hydr cylinders through a knee-lever which goes
over dead center at full open. I had to install a hand valve on one side for
balancing the opening and closing with changing temperature. This is much
simpler than an automatic balancer, and it will not work without any
balancing. There was no leak or any other problems in 7years of operation.
One safety feature I installed is a temporary pushbutton switch, which
makes it impossible to walk away while the door is opening. This makes me
watch the door all the time while it is going up or down. Some times, I even
open the door only partially and leave it there all day long on the hydraulics
without any problem.
I think you did the right pick with the hydraulics.
FWIW.
Richard Sohn
N-2071U
----- Original Message -----
Sent: Monday, August 14, 2006 4:54
AM
Subject: [FlyRotary] Re: Emailing:
DoorOpenLside.jpg
Hi Jarrett,
Actually, I believe that if the hose breaks
anywhere the pressure will drop everywhere
and the two cylinders will both lower (more or less) together. I could
be wrong about that, but until an hydraulic expert tells me otherwise, that
is what my eyeball analysis indicates to me.
Ed
----- Original Message -----
Sent: Monday, August 14, 2006 12:11
AM
Subject: [FlyRotary] Re: Emailing:
DoorOpenLside.jpg
Ed, looks like you have it well in hand.. any plan however, for a
hose break [or leak over time] which would lower one cylinder but not the
other?
Jarrett
----- Original Message -----
Sent: Sunday, August 13, 2006 9:52
PM
Subject: [FlyRotary] Re: Emailing:
DoorOpenLside.jpg
Good Idea, Lynn. Screw the hose in one side of
the aluminum block, up flow pushes through the restrictor and check
valve, back flow closes check valve and only flows through
restrictor. Shouldn't be that hard to make.
Thanks
Ed
----- Original Message -----
Sent: Sunday, August 13, 2006
11:36 PM
Subject: [FlyRotary] Re:
Emailing: DoorOpenLside.jpg
Not a bad idea, Ben. They would slow
down the opening a bit, but would probably slow down the closing
even more. I'll check into it.
Ed
Assemble a swing check valve in parallel with your restrictor.
So, most of the up flow is unrestricted and any downflow closes the
check valve and goes through the restrictor.
Or machine the whole thing in a small block of aluminum.
Lynn E. Hanover
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