Repairing a greenhouse curtain spool

Behind hardwood valances are the line spools for the greenhouse curtains that are in each of the dozen or so roof window bays. Several of them were broken or otherwise discombobulated. Here is a photo-documentary of the repairs one of them required.

This shows the valance already removed, the spring-loaded line spool exposed, and a pair of vise grips holding either end of the spring to hold it in tension and place while the line spools are to be re-wound.

Each curtain spools up to a tube motor, located above, around which the curtain spools when it is retracted to allow full sun. The lower edge of the curtain fabric is hemmed around an aluminum rod (seen askew above) which in turn is attached at both ends to high-tension fine cable lines that go down to the spring-loaded line spools (the large grey colored wheels) hidden behind the valances. Each tube motor that controls a curtain loads that spring when retracting the curtain. When switched to unroll the curtain, the tube motor rotates the other way, allowing the curtain to roll out. The spring-loaded line spools take up the lines onto the spools at either end of the spring shaft, keeping the curtain roughly parallel to the sloped plane of the roof window.

Except when the line falls off the spool and things are no longer so automatic:

These were designed by a local "Leonardo" and fabricated on site from various parts by an installer no longer around with whom to consult, so after consulting the inventor I was able to decipher the assembly/disassembly. At first I couldn't even find the switch that controlled these curtains. I finally found it in a control box labelled for another room and the up and down positions on the switch were reversed, so, that was logical. After several trial and error runs I succeeded in getting the lines on both sides reset in their spools...

and reloading the spring...

and optimizing the curtain's hang...

...and replacing the valance...

Here (below) on the right of the beam, you can see the tube motor that spools up the curtain, and the power line that runs to it. On the left side of the beam is the tube motor that runs the rack and pinion system that drives the venting roof windows that open and close automatically according to set points in the computer system that is the greenhouse brain.

That was a hot project! But some of our plants need shade from the full sun to thrive, and now all the curtains work and are extended!