Step 1: Prepping the Side Arm
Start with the 2 by 4 pieces of lumber that are cut to 30 inches for the top & bottom. Then, notch out a section (aka rabbit) at both ends of the 2 by 4 as shown in the photos. The section should be approx. 1/4” deep. This is only done for the top and bottom of the arm, repeat this step 3 more times.
Next, pre-drill two holes on the back side of the notched out section. Do this for both ends.