Modified MiniMill™ Stiffness Summary
The MiniMill™ has a stiffness of about 5 N/micron (27,000 lbf/in)
A 4 mm diameter 16 mm long carbide end mill has a stiffness of 0.6 N/micron (3300 lbf/in)
A 4mm tool cutting at 110 W (5% of the spindle power) will require a cutting force of about 11 N (2.6 lbf)
The Tool will deflect 20 Microns (0.0008 inches) under this load while the machine will deflect 2.5 Microns (0.00007 in)
The following slides show the analysis