This has to be the right spot to talk about gcode programming. Planning a 4th axis build with servo.

I'd like to program the 4th as if it were a spindle to rigid tap. I'll probably be laying it out along the Y with the spindle+ and tailstock-. Of course there won't be a tailstock because I'll be rigid tapping up that direction positively towards the spindle or 4th axis, if you will.

I can program to tap in this orientation but the code gives spindle commands, not rotary commands. What I want is to mount a tap on my Z in a holder and run it axially into the 4th.

Everything is servo closed loop. So I don't see why this shouldn't be possible.

So how do I convert this drill/tap cycle to switch the spindle with the 4th axis?

(Tool diameter 0.25)
G00 G40 G49 G80 G90
X0. Y0. Z0.
T1 M06
G00 G90 Z.25
G0 X0. Y0. S0060 M3
Z.1
G1 Z-.5 F3
G0 Z.1
Z.25
M05
M30

G80 seems to refer to a cancelled canned drill cycle.
No tp for Mr Cornholio? Tool Plane missing in action?
The spindle speed of 60 rpm matches the feed rate of 3 ipm. That's cool but rotary commands are usually given in degrees.
60rpm/20threads per "=3"per minute.
Wow what a formula! Maybe it's just me, but that's about all I could find on this subject of rigid tapping using a fourth axis instead of a spindle.

And then there's the Diameter 0.25x pi = 0.7854 Circumference thing. I just don't know the proper way to can this.

There's no reason I shouldn't be able to rigid tap using a fourth axis instead of a spindle to do so.

Doesn't everybody? Especially those without servo encoders on their spindles?

So that's my dilemma and I'm pretty surprised that there's not a lot of information about this. Card here to John Saunders.
Still waiting on that ground breaking video man!

But seriously thanks,
Alex
I'm pretty sure there's a simple solution to this that a lot of people could benefit from.