Garage torsion spring

[Everett M. Greene]

Very enlightening.

Method:

C = pi * D (geometry 101)

Unstated assumption of D = 6"

turns = distance / C

Results:

approx. 5 turns. Actually, less for typical 7' garage door

Now what's wrong?

[Goedjn]

Your objective? You appear to be trying to arrange the spring tension to be zero when the door's fully raised.

What you should be trying to do is match the spring tension as closely as possible to the load that the door puts on the spring through it's entire range of motion, while never letting the sum of forces be small enough (or negative) to let the door bind when you're trying to let it down. That is, if the door has an automatic hoist. If it's all manual, then you need the spring to EXCEED the applied weight of the door in the up position.

[Richard J Kinch]

The application requires a different formula.

The drum size assumption is wrong.

See my page at:

[Everett M. Greene]

My objective was to show approximately how many turns would be needed. Something more will undoubtedly will be needed to obtain proper and desired operation.

I was also trying to smoke out something more useful than "you're wrong" from someone named Kinch.

Adjust to fit, paint to match.