Hydraulic compression endmill holders

[Geof]

Does anyone have experience with the Schunk line of compression holders? They have two types; one is a solid body and they have a hydraulic mechanism that is pressurized by turning a screw and this compresses a steel sleeve around the shank of the tool, the other type has a nut like most collet holders but the nut compresses a polyurethane sleeve that expands sideways and compresses a steel sleeve to hold the tool.

The salesman claims much tighter tool holding than split collets, much less chatter because the clamping system also acts like a vibration damper, longer tool life because the cutting edge does not get micro-chipping from high frequency chatter and high helix cutters do not tend to pull out of the holder when taking good side cuts.

Anyone using them and can confirm these claims?

[tyty43086]

Hi Geof,
We use these schunk holders at my shop for our more automated processes. The type we use are the first type you describe, with the tightening of the screw in the hydraulic mechanism. A few things that we have noticed is better clamping force, less tendency for the endmill to pull out of the holder. Also our tool life has increased-- addressing your question specifically-- due to decrease in chatter as well as less runout. These holders seem to hold the endmill: 1)tighter and 2)truer.

As far as toolholding goes, something I was wondering about is those shrinkfit toolholders. The ones that use an auxiliary induction coil or something of the sort to heat the holder up and drop the tool in. Does anyone have experience with these? I would think that they would be even better than the schunk holders, just not sure if its god enough to justify the costs.