[update: 03/12/12] - I'm deleting the old .stl's as the new ones fix some of the flaws the first version had so if you want to print these, you want to use conn5.stl and hook1.stl

I've designed a hook system for hanging grow lights on a shelf using the honycomb holes in the shelf above to attach the light for the shelf below

These hangers were designed to fit the Lights of America brand of grow lights which are available for around $10 at your local large discount mart. But they should adapt easily to any brand of light which has the "keyhole" shaped connections for hanging.

The shelf unit that I am using is a Plano model 9524, 4 shelf unit.

The round plugs are designed this way to allow you to adjust the height of the light easily. IE, remove the plug, raise/lower the string, replace the plug

I added some action shots for clarity

Pic #1 shows the printed pieces with some string cut at about 1 foot length Pic #2 shows the string running horizontally thru the hook Pic #3 shows a loop pulled thru the center hole. This is a little tricky cause you have to get something pointed to reach down into the hole and grab the string and pull it thru. Pic #4 shows the short end of the string that has been passed thru the loop Pic #5 shows the loop pulled tight by pulling on the long end of the string. Friction keeps the rope tight inside the adapter Pic #6 shows the adapter ready to connect to the keyhole connector of the Lights of America grow light Pic #7 shows the adapter attached to the grow light Pic #8 shows the string run thru the hanger Pic #9 show the plug after it's inserted into the hanger. Again, friction is what keeps the rope tight inside the hanger but it also allows for easy removal and lowering/raising of the string which adjusts the light height