There is a minimum corner radius!
Designer must take size into consideration
CNC Milling is a very useful procedure. There are, however, a few limitations on what can be produced by the mill, and a few factors which must be considered to make an economical design.
1. The CNC mill uses rotary bits, so when milling inside corners a radius is unavoidable. Outside corners can be made quite sharp if necessary, but some inside corners can have as a minimum the radius of the cutting tool.
2. As can be seen from the photos, enclosed milling machines have a limited inside region. Naturally a piece which cannot fit in the machine cannot be milled by the machine. The interior of the CMU mechanical engineering CNC mill cannot accept pieces with any dimensions larger than 3’. Additionally, the movement of the cutting tool itself is limited; in general it is less than 18" in any direction so the part must be moved if milling is to be performed on more than this range of distances.
3. The workpiece must be solidly mounted to the milling table by a bracket piece, bolt holes, or a clamp. This should be taken into consideration when designing a part to be CNC milled. Of course the part can be mounted by a flange which is manually removed after machining.