I'm converting (yet another) Benchan 4000 VMC for use with Mach3, and I'm exploring the possibility of adding some type of tool changer. (The donor came with a rotary 4th axis, but no ATC.)
My puzzle for the day is, how does the factory-ATC lock the spindle in place while loosening & tightening the drawbar? The donor has a hole in the left side of the spindle carriage, apparently for jamming in a bolt or some other object, to catch a hole drilled into the side of the spindle itself. I can imagine adding an over-center spring mechanism to insert (and withdraw) the pin, then giving the spindle a quick blip of power to rotate the shaft until the pin catches, but this seems ... inelegant.
Is there anybody out there using a Benchman or Intelitek machine with factory ATC? Is there a clutch, or brake, or ???
Thanks for your time.