Flute echo over holes?

[Matthew Hajicek - Singularity]

My material is H13 at RC 46. When finishing a wall that has a hole in it I get a visible echo above and below any sideholes, spaced by the pitch of the cutters helix. Does anyone know a good trick to avoid this, or do I just need to do a whole bunch of skim passes until it diminishes to an acceptable level? At this point I can't do the sidehole after, since our process has it being done before heat treat.

[EX-wccprogrammer]

The only success that I have had is by plugging the hole. You might have better luck with a variable helix cutter to minimize the harmonics.

 

HTH

[K2csq7]

Do the holes have nice chamfers, or 46 Rc. burrs .05 thick/high from the drill exiting.

 

Did you try conventional milling instead of climb?

 

Smaller dia cutter....

[Matthew Hajicek - Singularity]

Holes have nice chamfers. Have not tried conventional milling, suppose it's worth a shot.

[mkd]

finish cut above the hole(s) first, then semi finish to bottom of hole followed by finishing below the hole?

[gcode]

Extened lenght relieved shank endmills

making a pass above and below the holes then one in the middle????

[Mic6]

Ramp/Depth all the way to the bottom