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5-Regular Member
August 16, 2023
Question

Size of Countersinks on curved surface

  • August 16, 2023
  • 1 reply
  • 1951 views

Apparently, the geometry of a standard hole countersink is incorrect on a curved or round surface. The size I enter (which becomes its callout on a drawing) becomes the major dia of the resulting ellipse - but the countersink is to be measured across it's minor dia (ASME Y14.5-2018 4.5.13). I didn't pay much attention, but now with 3D printing and other rapid prototypes - it has become a problem: the actual physical countersink is too small. Is there an easy method or fix other than creating a plane and modeling a revolved cut in the correct orientation? 

 

 

1 reply

19-Tanzanite
August 16, 2023

Yeah, I think you have to have a work-around.  I suppose you can also switch to "simple" hole and sketch it out, as the minor elliptical diameter needed at the countersunk edge will depend on the curvature of the surface to be drilled.

 

Eg. M3 hole drilled into a Ø10mm shaft (Ø6.94 countersink diameter):

pausob_0-1692219618201.png

 

Patriot_1776
22-Sapphire II
August 17, 2023

Agreed, even changing the hole tables probably wouldn't work because you don't know the diameter of the cylinder you're going to countersink.