Die Cast Mold

[IdeaMakers]

Hi All, looking for comments and opinions on making a die cast mold for beads that I use. Here's some photos rendered in VCarve of how I think I'll mill the mold but any suggestions would be appreciated.

   

   

Basically this is two pieces of cold rolled steel (4" x 6" x 5/8") and I'm using a 1/4" endmill and ball nose. The rows in the middle are round beads 1/2" in diameter and I'm using a fluting path with a 1/4" ball nose to go a 1/4" depth over a 1/2" length. The rows at the top and bottom are a triangle shape using the same ball nose with a fluting path running from an 1/8" to a 1/4" over a 1/2" length. The channels connecting the beads are 1/8" deep and 1/4" wide and the pour channel in the center is 1" wide by a 1/4" inch deep (1/2" inch when put together).

The thought is to pour metal down the center to flow up the side channels removing the air as it goes up. The beads would then be cut out and a center hole would be drilled. I've milled the surface flat on my cnc and being cautious with it I can mill 0.001 at 70 inches a minute without to much fear of breaking the bit.

I know the large mill at SC could probably go a little faster but only being able to use it 3 hours once a week it would probably take a month to complete, where as I can mill over a 2 week period without driving the neighbors to crazy.

Any thoughts on the design and function of the mold? Being the first one I've tried to make I in that familiar unfamiliar space of doing something new.

John