I want to make an aluminum mold for hand layup of carbon fiber boomerangs (see attached picture). A friend machined one for me on an industrial CNC mill, but I would like to do this myself with a small CNC-converted mill, if possible.

The machined cavity is only .055" at the deepest, but the shape is too large for a small mill to handle in a single operation. Is it possible to divide and conquer such a task?

The "long" arm of the boomerang is about 12.5", the short arm is about 8", and the cavity surface doesn't have a flat spot on it. Is this possible on a small mill conversion, or am I dreaming?

Thanks, Carl

you could build a rotating fixture plate with two plates and a center dowel ,

fix the bottom plate to the table and rotate the top plate using a dowel pin thru the center of the two plates , use dowel pins for locating and bolt holes to hold down the top plate ,
if you use the center dowel that your plate rotates on as your work reference point then it would be a no brainer

An alternate way to dertsap's is to make it in two pieces with a kind of key/socket joint at the corner. Draw the complete thing and then separate the two arms of the shape across the corner with an interlocking shape. Machine each half and then asemble them at the interlock to get a whole.

Great suggestions guys, thanks much. Do you think the complexity of the surface (i.e. no flat surfaces) be a problem for a small mill conversion as opposed to a big industrial machine?