Helical Involute Gear Milling 4 Axis CNC

[RhiaMar]

Hi,
Thanks for adding me to the forum, I am very new to gear machining and so I could have a lot of questions.

My first question is the gear data for the gear I am trying to machine calls for a helix angle of 52.295 degrees but the software only allows me to input to 2 decimal places which has an effect on the size of the gear, is there a way to add the helix angle as 3 decimal places please ?

My second question is regarding creating a form slitting tool to produce the gear profile. If I use the 2D DXF output drawing, would that be the correct form to CNC grind onto a tool does anyone know please ?

Thanks

Andy

[ArtF]

Hi Andy:

Sorry for any delay in your post, for some reason the forum was waiting for approval...

>>ear I am trying to machine calls for a helix angle of 52.295 degrees but the software only allows me to input to 2 decimal places which has an effect on the size of the gear, is there a way to add the helix angle as 3 decimal places please ?

Sorry, but in the code it does limit to 2 decimals, though I dont think that 3rd decimal will do much, perhaps less than a 1/10 mm or less.

>>My second question is regarding creating a form slitting tool to produce the gear profile. If I use the 2D DXF output drawing, would that be the correct form to CNC grind onto a tool does anyone know please ?

No, to make the helical you would use the normal non helical output dxf for the tool form. The tooth form is taken from the dxf shape
of the tooth when viewed on the gear plane, if cutting with a tool , the normal DP involute form should be used. ( Create a dummy DXF of a non helical gear and the tooth displayed should be the cutting shape, This is because it cuts at the helical angle and will in the end create that widened tooth shape on the 2d view. Typically, you can run a normal DP involute in a helical gears mesh when rotated to angle, so the cutting shape is the same as that involute non helical gear.

Art