Thread Milling Question

[rocket_troy]

Les and members,
When configuring a thread milling tool for the tool table, there's a parameter listed as "Thread Depth". Can you possibly elaborate on what exactly that is? I'm assuming it's the measurement from the edge of the bare shank to the very end tip of the thread profile?

Thanks,

Troy

[Les Newell]

That is a confusing one. I need to add a graphic to help explain it. Take a look at the diagram here https://www.boltscience.com/pages/screw3.htm The thread depth is the distance between the major diameter and the minor diameter. I.e it is the depth of cut.

[rocket_troy]

Thanks Les. So, just to confirm the difference between the major and minor diameters divided by 2 yeah?

Troy

[rocket_troy]

Les,
I'm still confused on this. That depth input just doesn't make sense to me. Your explanation makes sense, but the results don't seem to match up with that. ie. if I take the tool "Diameter" input as the major diameter of the thread mill tool and leave the "depth" at some arbitrary number that's small enough not to produce an error, then everything is dandy as Sheetcam appears to go by the *tool diameter* parameter for the thread milling process to produce the actual helical interpolations. So, if Sheetcam is using the tool *diameter* input for the tool's outside thread diameter, the "depth" should actually represent the distance to the minor diameter in radii terms. However, what it appears to represent is a distance *beyond* the major diameter of the tool.

Essentially, what doesn't make sense is the hole clearance error check is: tool diameter + (thread depth * 2) > Thread Diameter = Clearance Error

which assumes "tool diameter" is the *minor", but the G Code produced assumes "tool diameter" is the *major"

Troy.

[rocket_troy]

Re-reading what I explained there probably isn't technically correct. Nevertheless, something doesn't appear to match up with the clearance checking and code processing. One thing is for sure - I'm still confused.

Troy