Cat-50 Holder run-out

[qtrhorse]

We have some 50-taper machines (SNK-machines with in-spec 3500lbs. of pull pressure) that have habitually collected pitting and wear on the holder taper.
It has resulted in regular spindle taper regrinding.
We have been recently evaluating the run-out condition of our holders with a proper check fixture, one holder company recommends replacing tools with .0003 or more run-out.
We had to raise the standard to .0005, which still captured over half of our tool holders, many of the new and unused.

Can anyone accurately regrind these 100s of holders or will they need replaced?

Has anyone else had similar machine spindle / holder wear issues?

 

[unclesyd]

I think everyone has this problem to varying degrees. We made the mistake of putting a machining system in an area where we had conditioned air, cool but high humidity. This was a disaster as far as tooling and spindles were concerned.

Here are just two of numerous companies that can refurbish tooling. We had Locher do some rework for our manufacturing area and I can't recall any problems.

http://www.spindles.org/default.asp

http://www.precisionspindleinc.com/default.html

 

[qtrhorse]

Thanks for the great links!

We have a company that reginds our spindles, my search is for re-justifying the holder tapers.

Or maybe finding others with SNK spindle issues.

Thanks for your input!

 

[Tmoose]

I'm surprised new name brand tool holders have more than 0.0005 inch runout between taper and tooling bore. I'd look at checking out my checker. If the checker grips the entire taper I'd work out a way to index a "bad" tool 180 and see if I get the same runout and high spot. If the checker references Vees or rollers on the taper I'd suspect the axial location or thrust surface runout could induce spurious runout

 

[qtrhorse]

The 'taper checker' is strictly for checking the concentricity of the taper, it locates on rollers at 11 & 1 o'clock, high and low and in the center on the opposite side dead inbetween the high and low rollers. It has indicators at the above and below, inline with single roller.

It comes with a standard and is made by a top holder manufacturer, who gave us the .0003 spec which few of thier tools measure up to.

You see if the taper isn't perfect it allows the holder to wollow in the spindle under cutting conditions, causing premature wear.