Thanks again both of you for your quick reply
. Thanks to Tim and one of my friends I now understand how to change steps. I have my model now. It is complete with an accurate instruction manual.My next step is going to be making a multipart model. Thanks Willy for your model and the tip. It seems like I'm going to be studying buffer exchanges and hopefully it'll click. I must admit I'm alittle thick when it comes to self teaching but I'll do my best. Thanks again
