I'm sorry but I think it's wrong for a seller like Marco or anyone else to sell a part that they know is defective and will break. We need to get them all off the market and in the garbage. Someone needs to make these gears. In my experience it's the round gear that goes bad the most. The one I got made of Delrin is still going strong but it was a prototype and not being sold. $100 is too much for either one of these gears, if they were made with the proper material there is no reason they shouldn't last much longer.