I bought this model a long time ago and never unpacked and assembled it until today. Of course there is a part missing and it is out of warranty, even though never used. I called customer service today, and this model is discontinued with no parts available to purchase.
It is a metal pin that snaps onto the aluminum Dec Worm Shaft. The protruding rectangular shaped metal pin fits into the Dec motor drive and causes the shaft to rotate. Without the pin, the whole system is useless! Can't believe it. I spent all day on this.
What can be done??