[adlucy]

anybody came across this .after you have cut a thread you go in with another tool to remove half of the first thread to stop feathered edge or burrs it is actually called half threading anybody explain the principle thanks

[dcoupar]

anybody came across this .after you have cut a thread you go in with another tool to remove half of the first thread to stop feathered edge or burrs it is actually called half threading anybody explain the principle thanks

I've seen it called Higbee Start, Higbee Cut, Blunt Start... "half threading" is a new one to me. I'm betting if you search the threads in the Zone, you'll find dozens of posts for "Higbee".

[adlucy]

can anyone confirm does this create a taper or does the x value stay the same all the way to remove first thread

[dcoupar]

can anyone confirm does this create a taper or does the x value stay the same all the way to remove first thread

I haven't done it myself, but I would assume it ends up something like the attached .jpg.

[sinha_nsit]

I do not have enough practical experience, so this may be a silly question; but I do not understand why don't we turn first and then make threads, rather than thread first and then remove a part of it!

[JimBoyce]

You might consider a left hand tool and thread away from the spindle with a lower RPM.

[norbert.barnard]

chamfering is also influenced by parm 5131.

[norbert.barnard]

removed

[StarCNC95]

Hello im new so I wasnt sure where to post this but I have a G32 question. Ok lets say I am running a 5 inch screw with a very deep thread, .06 deep on a side(bone thread).35 major diameter. It will run 2.5 inchs or so fine but then the longer it gets it starts chattering.(single point double lead thread .2 lead) I can fix this chatter by slowing the RPM's down. But my question is because im pretty sure I tried this before and it didnt work. Can I change the rpm at the 2.5 inch mark or so and still come in the same spot or will it missmatch? I hate slowing down the RPM on the part that is fine until you get to the area that has a chatter issue. Has anyone changed RPM's in G32 mode?
Thanks!

[Daleb]

you cannot the RPM when threading on the CNC lathes I've ran. Even if you back and thread the same part changing the RPM will throw it off

[sinha_nsit]

In any threading operation, if you change the rpm, the tool would start following a different helix. And the first few threads are always incorrect.

[txcncman]

Only way I know where a possible speed change can happen is on a machine with C axis.