Wear in work holding tools
Wear in work holding tools
(OP)
Fretting is a wear phenomena when two steel parts for example a holder and spindle mouth, rub against one another. Fretting is caused by imperfect mating between
toolholder taper and spindle, creating vibration and heat which develops the fretting. A cermet coating of tungsten carbide can reduce fretting. I would like to know how others have reduced fretting in work holders.
toolholder taper and spindle, creating vibration and heat which develops the fretting. A cermet coating of tungsten carbide can reduce fretting. I would like to know how others have reduced fretting in work holders.
RE: Wear in work holding tools
Modern CNC machines with toolchangers have their drawbar tension checked during a proper calibration cycle, but I've still worn out many toolholders over the years. I remember running an old Cincinatti Simplex horizontal boring mill many, many years ago, with 50 taper spindle and about 25 or 30 HP and a manually tightened drawbar to retain the toolholder. I could remove over 300 cubic inches of HY100 in 20 minutes during a roughing pass with no ill effect after dozens of such passes. I highly doubt the same could be accomplished on a CNC center. I still had to rotate 9 inserts on the shell mill and shovel chips after each pass, but the toolholder held up fine.
It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.