andy pugh wrote: > On 16 August 2012 15:58, SourceForge.net <[email protected]> wrote: > > >> Emc could benefit from a tapping cycle that does not rely on a spindle >> encoder but instead uses floating taping heads. >> > > How does that work? Do you have to assume that spindle speed is > approximately correct, and not care too much about the tapping depth? > > Or is this for use with the friction-reversing heads? (though I still > wouln't know how to control depth) > Yes, and probably yes. I did this using a Procunier "CNC" tapping head. All it has is a reversing clutch that senses axial push/pull on the tap. When pushing, it engages a 1:1 forward drive. When pulling, it engages a 2:1 reverse clutch. Works great on through holes, but would be tricky on blind holes without a lot of end clearance.
So, this was not actually a floating tap holder, it only had a little bit of clearance, maybe .020" between in and out. With a floating tap holder, it may take a lot of Z travel before the tap "bites" in and starts to feed. And, this will be variable with each hole. Also, the time to reverse the spindle will be fairly long, and the CNC program doesn't know when to begin retracting Z. Jon ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
