[rough_cut]

Hi,

I have a 2.5" deep pocket to cut with 3/16 overcut in the corners to house a number of square optics. The tolerance is tight and I'm having issues with deflection. Using a stub flute, ex-long, reduced neck cutter, 3/16 dia, micro grain solid carb. 4fl. max spindle rpm 8000. Any suggestions would be most appreciated.

[dxxx]

you will need to mill in steps if posible or rough pocket out first leaving only .005,then finish with several passes in steps.
if i understand your post.

[rough_cut]

its deflection in the corners that I am worried about, I am over cutting the corners by half the cutter width to accommodate a square optic and with the length and dia of the cutter i have almost no rigidity. If I take very light cuts will that help or will the cutter just skip around on the surface?

[ironDigit]

i'm a low speed guy but,

deflection should be able to trace back to feed/speed error (to low or to high i dunno).
feed is a spindle speed / em diameter / material / machine stabillity related issue and these all go into the math .
machine stabillity is the one i used to under estimate but with these small dia. EM's the feedrates get so low per revolution per tooth that the slightest misalignment ,backlash ,temperature inaccuricy can overload the cutting cappabillities of the EM.

atleast thats what i think the salesguys are trying to make me believe.and i keep buying.

try a slottingsaw these seem to work alot better when it comes to thin slottin or slotting in general but hey ,remember i'm a low speed guy.

make sure the cutter was designed to deliver results to the tolerance you are pushing for ,or you might be chasing gremlins.(I assume you already checked for thoose)

good luck.