GearHeads Corner

Cutting clock gears with thin slitting saws is very promising but the segmentation is hard to optimize. Too high a segmentation impacts cutting time badly. Here is a closeup with segmentation of 8



showing ridges that will impact friction of a gearpair.

How about adding another machining process for each tooth flank that has the cutter positioned, in X, on the middle of the edge of the wheel and does a Y move into the root generating the tooth face by coordinated motion of Z and A with the Y infeed?

If a low feed rate can be called up for this then a very smooth tooth can be made with little impact on the total cutting time.

This would produce a dished face in the dedendum but for thin gears and a reasonable saw diameter this would not be objectionable. If one wanted to avoid the dish for cosmetic reasons say when cutting a small stack of gears, then the Y-depth could just kiss the root in the middle as the tooth flanks are probably flat in this area.

John Prentice

Hi John:

  I see what you mean. Were these done with the "Maintain depth" option on do you know? ( Just curious.). I had thought
maintaining depth on the slit saw would help keep make the tip of the blade have less of a stepping effect on the result,
but had never confirmed it.

  I think its quite possible what you suggest would clean up the cut marks, depending on saw diameter and thickness of
the blank. Im willing to look into adding that , doesnt sound all that difificult in the end. It will be the fall before I get to it,
but consider it onthe fix-up list rather than a feature request.

  Thx for  the photos, they really help to show an issue.

Art