[rustycollet]

like i said, ghetto but it worked, lol . I'm sure it's been done before, but I couldn't find it on a search.

enjoy the laugh:


...pardon the "crunchy" noise that happens on slow Z moves, sounds MUCH worse than it really is....
Down and dirty tapping method allowing axial float via Quill movement. Watch the red quill travel indicator make up for discrepancies in head Z feed vs tap feed. For the tension part I loosed the quill clock spring tension. For the compression spring I just put some springs in between the quill "clamp" and the head...stacked on top of a socket to keep it as rube-goldberg as possible. ;-) I have a versatapper, but there are some reasons a tension compression method worked better than a clutch type when wanting to use the CNC Z feed rather than hand feeding the quill. Notice at 0:29 where Z head feed was stopped and spindle coasted to a stop,pitch- pulling the quill down . So there was some unwanted Z movement in the tap that the quill tension spring made up for. Then the tap spun in the chuck a bit. This was just an experiment.

5/15-18 tap . Head down feed at 95% of pitch induced feed (4.75 ipm vs 5 ipm), 90 rpm
(ideally different rate for out/upfeed..but forgot)

g00
m3
g1 z-1.1 f4.75
m5
g4 p3
m4
g1 z.1
m5

[Roadstercycle]

Rusty, Great post! The tap slipping in the chuck is a good thing. I've tapped this way for a long time and the tap slipping will save you from breaking one off. Took a little while to get the feel for tightening the chuck just enough but I've not broken a tap in a very long time.

[rustycollet]

just noticed many typos in my post, but too late to edit - oh well, the idea still comes across, it just sounds like i have bad grammar/spelling & i have some very special tap diameters, lol.

I also configured Mach 3 to have about a 1.5 second delay between every M3,M4,M5 to allow for coasting to a full stop before reversing.

IMPORTANT: I eventually used a proper T-C tap holder ... I DID have a problem with the motor tapping many holes per hour this way ...about 300/hr...it would become sporadically unreliable reversing and starting and would sometimes trip the breaker. Then I found out these capacitor start motors are not rated for nearly that amount of starts/per time.

I switched to my tapping head, but this would work in a less duty cycle intense situation,or with a different type of motor.