Single point threading

[kdoney]

Is there single point threading on the mill side? Either blind or through?

[miljnor]

Milling threads doesn't require anything special from the controler.

You just need to be able to program a helical toolpath that mimics the thread.

for instance in increamental mode a tool path for a 1"-12 tpi thread would be something like:
G91
G1Z.0103F45.68
G42G0X-.0728Y.0728D11
G1X-.0013Y.0064
G2X.0741Y.0863Z-.0103R.075
Z-.0833I0.J-.1655
Z-.0834I0.J-.1655
Z-.0833I0.J-.1655
Z-.0833I0.J-.1655
Z-.0834I0.J-.1655
Z-.0833I0.J-.1655
Z-.0833I0.J-.1655
Z-.0834I0.J-.1655
Z-.0833I0.J-.1655
Z-.0833I0.J-.1655
Z-.0834I0.J-.1655
Z-.0833I0.J-.1655
Z-.0833I0.J-.1655
Z-.0834I0.J-.1655
Z-.0833I0.J-.1655
X-.0973Y-.2994Z-.05R-.1655
X-.0092Y.1133Z-.0103R.075
G1X.0048Y.0045
G40G0X.1017Y.0161
G90Z.1
M99

notice that all of the z depth moves are the pitch of a 12tpi thread which is 1/12=.0833333333

[Geof]

You do not need anything special in the way of tooling. I have taken a lathe threading tool held in a collet and milled threads. You need to know the diameter the tip traces out when the tool is rotating. You can estimate it with calipers then get an accurate measure by boring a hole with it and measuring the hole size. Rough the hole out first to to the estimated size, threading tools are not meant to take big side cuts.

[kdoney]

Thanks. Is there any way to use a lathe threading wizard to come up with a program and then just flip the axes to use it in a mill? I'm g-code challenged.

[miljnor]

The mill requires totaly different coding. and thus the short answer is no it wouldn't work.

And as to what Geof said: I think he forgot to qualify that he was probably using indexable tooling as if you take solid carbide and spin in in a collet you will have a very close encounter with the backside of the tool.

Don't ask!

[Geof]

Don't ask!

Why not?

Yes, it was indexable 5/8" dia. shank.

Incidentally on all your Z-.0833I0.J-.1655 lines why don't you do
G91 G02 Z-.0833I0.J-.1655 L15

[miljnor]

i would but it's a CAD/CAM generated code. As I was just making an example didn't pay too much attention to the code itself

[Geof]

I should have figured that because the string of moves actually corrects for round-off error. Which is really quite elegant.

[miljnor]

Got to love those cad cam progs!

I would have corrected for the round off too! REALY! No I'm not kidding! Well.......