Window Air Conditioner Brace Leveling Shim

Print in ASA, PETG, or PC 15% Infill, Organic Supports on the build plate.

A pair of these parts can be placed on an adjustable window air conditioner brace. Often, the brace is insufficiently adjustable to obtain the optimal support angle. Too much angle and the unit is at risk of sliding off. Too little angle or negative angle and water will leak into the house. 

1. Follow the window ac brace installation instructions.

2. Measure the window AC unit and ensure that the brace is adjusted so that the printed shims will be in a position to support the AC unit at the correct angle. Note: If you have insufficient angle on the support brace; the correct shim position might be to far out for the depth of the AC.

3. Place a shim on on of the support arms and place a level on it and the window sill support point. 

4. Adjust the shim position so as to maintain a gentle slope away from the house.

5. Use two large zip ties to anchor the shim to the adjustment holes and keep it in position. You will link the Zip Ties together with a female end on each side.

6. Repeat the process for the other support arm.

7. Double check the stability of the AC Support Arms. Note: Sometimes the arms compress under load so push down on the brace and ensure that your desired geometry will be achieved once the setup takes the full weight of the unit.

Tips. Be sure to properly flash with plastic bags. I like to use a heavy duty trash liner or a heavy duty clear plastic liner. I trim it to the width of the window and place about 2 feet outside and 2 -3 feet inside the window. Then place the bracket on top so that plastic makes a protective layer between the brace supports pad and the siding. Then take the interior plastic and bring it back on top of the brace and slide it under the shims. If you wish; you can place microfiber towels in zip lock bags and place it in between the top and the bottom layer of plastic on the SIL and it will help to insulate and seal that gap area. Doing this will help the setup to be properly flashed so that rain water will roll off away from the house and not into the window.