My buddy and I have been talking about casting aluminum for a while and I needed end caps to stuff into the stainless steel rollers I had knurled for a grain mill. It seemed like a perfect match for a project.
So I am in the process of building a monster grain mill (later instructable?) for my brewing hobby. Yes, I can buy a mill for $150 give or take but then where is the fun in that?
Things to consider before beginning:
You are dealing with molten metal. It is serious. Do not attempt while intoxicated or on the way to such a state. Imagine that feeling you get when you burn your tongue on cheese of a pizza that was eaten too soon after coming out of the oven. It is like that only times 10 on whatever the metal has dropped onto. It is really hot. We took the precaution of using welding gloves, eye protection, leather aprons, work boots, long pants even thought it was 90+ degrees out.
Here are some of the things you will need to duplicate this adventure:
-foam insulation board (from local hardware store) this is the open cell stuff that shapes well
-drill press, while not required technically, very helpful
-drill the size of the following bolt
-files and rasps
-steel bolt and washers
-flame thrower (the kind they use to melt tar on roofs) like this
-crucible (we are using 1/2 inch 4x4 steel square stock with a 1/2 inch plate welded to the bottom) for holding the melted aluminum
-firebricks or regular for making a furnace/oven to heat the metal in
-desktop lathe made or bought
Step 1: Making the Lost Foam Template
Step 2: Start the Foam "milling"
Step 3: Cutting the Foam
Step 4: Tools for Shaping...
I would stop every now and again with some calipers to make sure the outer diameter is still good. The last photos is the prototypes all lined up (one has a gouge from forcing things).
Step 5: Casting Day
Step 6: Heating Up the Metal
You can see the crucible in the furnace and the torch coming in at the bottom. (ha, just noticed the image is upside down...).
You can use regular brick, I guess the just end up cracking quicker. Hopefully these hold up until I get around to building a better furnace.
Step 7: Pouring Into the Mold
The bolt you see in it was pounded free. Seems steel wont melt with the aluminum. :-)
Step 8: Machining the Roller
Step 9: Milled Smooth
Rinse and repeat 4 times.
Here you can see it in the roller. Soon you can see it in the mill when I finish that project.
Let me know if you have any questions or have feedback on this instructable.