Floating Tap Cycle?

I have searched and have not found much info on using a floating tap head with linux cnc. Can anyone point me to some info on doing this?

You use the normal rigid tapping G33.1 with a floating head or a rigid head.

JT

I guess I should provide more information I found the below thread but it was from 2012 and would like to do the same thing. I do not have a spindle encoder. I see it working like as follows

start the spindle at the set speed,
wait for the at speed signal
feed the z in at the at the proper feed rate
stop the spindle
reverse spindle but do not wait for at speed
feed the tap back out


forum.linuxcnc.org/forum/12-milling/23279-non-rigid-tapping

Do you have a floating tap holder? I have one and there is very little movement in the head in fact only 1/2" of travel. IMHO a safer bet would be to add an encoder to the spindle. What kind of mill is it?

JT

I have not yet purchased the floating holder, I have used a few older mills that supported tapping in this way. Generally the z feed is set slightly lower that the calculated feed so the holder extends a bit while feeding the tap in to give a bit more compliance while the spindle stops and reverses. The mill I am using is a Bridgeport Boss 5. Yes the encoder would make it work but I was interested in trying to get it to work without the encoder as mounting is an issue with these mills.

It has a draw bar spindle?

Without an encoder its just really G code and you have to figure out the time it takes to reverse and perhaps put a pause at reversal. Are you using LinucCNC now on the mill?

JT

Yes I am running linux cnc now, I could handle the gcode and probably tweak my post to make it happen, the only thing I thing that would be an issue is the at speed signal causing issue.

Just put a pause after the M3 to make sure the spindle is up to speed.

JT

What spindle do you have in it?

JT

I have the quick change 30 spindle in it. With the spindle at speed I worry that Linux cnc will wait for the spindle at speed before starting the z retract.