Re: [CAD_CAM_EDM_DRO] Bagged an Ahha-ready CNC mill!

In a message dated 06/08/2000 6:30:20 PM Hawaiian Standard Time,
janders@... writes:

<< Peter,

Can you tell me more about the difference between qualified and
non-qualified holders, and the consequences for using non-qualified?

Jon >>


Jon,

A Erickson QC qualified holder has the flange dimensions carefully
controlled. The clamping nut on the quick changer must engage and clamp the
holder in under a fraction of a turn. I think it is approximately a quarter
turn. Since they are using a relatively fine thread on this nut, you can see
the standard +- .005 on flange thickness will not work. They hold the flange
side opposite of the taper to the close dimension. Hence, many 30 taper tools
will fit in the holder, only qualified ones will allow the quick change nut
to close and tighten properly. If you have holders that are plus on the
critical feature, then grinding can result in a usable holder. Many times
though, especially on setscrew type endmill holders, the body diameter is too
large to pass through the locking nut. The qualified holders have the necked
down waist.

On my machine, the hole for the drawbar was drilled. I've heard many are
not. So, push come to shove, I can still use a drawbar to hold non-qualified
holders by removing the clamping nut.

Hope this helps.

Peter
THRD, Inc.