Jim, the reason I used metal conduit, uni-strut, and metal jack: I needed to make certain no single componant would fail or move. The rollers were the only item which I wanted to move. Wood may work, but the cross arm would be a weak point depending upon how it was secured to the pole. My pick points were a 2 to one leverage, but the upper shelf battery was a longer reach and I had a 10 ft. 1 1/2 rigid conduit slid into the end of the 10 ft. 2 inch rigid to leverage that battery out. The batteriy positive stud was taped off.