Hi everyone, Here is the build thread for the Peake 2, my next engine. I will be making 25 of these and they will be single acting "upside down" steam engines. The first parts I need to tackle are the patterns for the castings. I decided to begin with the flywheel because it is the most fun! The flywheel is 3.5 inches or 89mm in diameter once finished. The hub and curved spokes are cast from alluminium and the rim is mild steel (to add weight and improve appearance). Here are the pics. Preparing greensand from raw sand: Drying the sand. Sifting the sand to remove unwanted larger particles. Adding bentonite clay and water until correct consistency is reached. The clay must not be too wet (could cause an explosion when poured into) and must be well mixed. A good test is compress a handful of sand in the palm of your hand, hold it with a thumb and finger at each end and 'snap' it in half. The break will be clean and no sand will fall away if everything is right. As I don't have a CNC mill, I have to make my patterns the old fashioned way. I have cut the hub and rim into a block of wood, which will act as a 'stamp' in the greensand. The spoke stamp is formed from a piece of brass. In this picture it has been tapered by between 1 and 2 degrees. As the spokes are curved, the spoke stamp must be curved also. The spoke stamp is parted and ready to go. I had to re-make both these stamps with slightly larger dimensions for reasons which will become apparent, which is why some of the following pictures will show modified versions of them. The spacing for the spoke impressions in the sand is controlled by this piece of paper. I mounted a pencil in the toolholder so I could accurately draw on the paper. The paper is marked out with the OD and 5 marks for the end of the spokes. I used a drill bit to index the spindle, a trick I picked up from someone on this forum. Finished paper. Making the hub and rim impression in the sand. (this picture is of the impression made with the third version of this stamp) Indexing paper is in place. Spoke impressions are now made corresponding to the marks on the indexing paper. Impression is finished Forming the Cope The cope and drag are in position, ready to be poured. Scrap alluminuim is heating up in the furnace (shown without lid). The firt pour! Failed! This is why I increased the dimensions of the stamps. Skipping forward to the fourth Pour. And the sand reveals a welcome shape. So here is half of the pattern, prior to machining and tidying up. I had to call it a night at this point - getting late! In the morning I will be making the other half of the pattern.