I’m in the process of buying all the parts necessary to build a coffee roaster. I’ve ordered the 2lb rk drum, a rotisserie kit, and a motor which has a 3/8 shaft. I’m not sure about the couplings though. I’ve never built anything like this so I’m not sure how these couplings work or which ones to get. (I’m VERY much a newbie) Can you tell me the parts I need to couple the motor shaft and the rotisserie rod?