[Buk]

New here; so many fora; none seem particularly appropriate to my question, so I'll ask here and hope to be redirected appropriately.

I need to know what type of machine, cutter, and the practical limits, for cutting two different kinds of 'slot' into tool steel:

1) A radial spiral slot (think: clock spring inverse) into the face of a round workpiece.

2) An axial helical 'slot' through the depth of a cylindrical workpiece.

My naive questions include:

a) Which type of machine (mill, lathe, other) is appropriate for each type of cut?
b) What type of tool (rotating side cutter or end cutter; lathe parting-tool type; other)?
c) How thin can I make the slot?
d) How deep can I make the slot?

Thoughts?

Cheers, Buk.

[Jim Dawson]

My naive questions include:

I'll take a stab at this. There are a lot of variables here and without any other parameters other than stated it's difficult to give a definitive answer.

a) Which type of machine (mill, lathe, other) is appropriate for each type of cut?

A lathe with live tooling and a C axis or milling machine would work. A milling machine might give better tool path options due to the CAM software available.

b) What type of tool (rotating side cutter or end cutter; lathe parting-tool type; other)?

A rotating tool would be what I would use. Due to the changing radius of a helix, a fixed grooving tool would not work well.

c) How thin can I make the slot?

I have slotted steel with a 1mm endmill. Requires a rigid machine and good control.

d) How deep can I make the slot?

At least 5x the diameter of the cutter, maybe deeper with some care and ideal conditions.

[Rich Carlstedt]

Bit late, but Jim answered it pretty well.
We did exactly what you are inquiring about making round dies for the plastic extrusion world
We used a Horizontal Boring mill as it gives the best rigidity for 3 or 4 axis work
Using a Lathe or Vertical mill with indexing head can give flex to tough work.
We used Ball Endmills for most cutting- as it was smooth grooves we wanted.
Using a Horizontal solves the chip evacuation problem as well , so deep depths were not an issue