I am starting to build a pm research 2a steam engine from their casting kit. Have not worked with castings before and have run into a problem with how to hold the cylinder head casting to machine it. Its a roundish disk about the diameter of a quarter and a little over .175 inches thick. I need to turn it down to the diameter of the cylinder casting and then face one side to total a thickness of .125. I found a link where they sandwiched a part between the chuck and the tailstock using double sided tape, emery cloth on the chuck side and puck on the tailstock side. Is that the standard method or is there another way to handle this? Any suggestions would be appreciated. I am just a hobby machinist with not alot of experience at this point. Based on the threads I have followed on the forum this is small potatoes compared to the amazing builds being done by others.