Mike Dobony wrote:

"Joseph Meehan" wrote in message
m...
Mike Dobony wrote:
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The spring is supposed to do all the work and negates the weight of
the door. That is what it is designed to do. A 1/4 hp opener SHOULD
be able to open any properly setup door.


Maybe not. Remember inertia from your high-school physics class? The
tendency of a body to resist acceleration; the tendency of a body at rest
to
remain at rest or of a body in motion to stay in motion in a straight line
unless acted on by an outside force.


Yet isn't the spring's function to neutralize this force? The spring
overcomes this to negate the user or mechanical opener from having to deal
with the full weight and inerta of the door.

Yes.

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