The Causes
The Results

If you have answered "YES" to one or more of the questions listed above your
machine may have "Spindle Bell Mouthing Syndrome."

    Causes for this syndrome are:
            a) Heavy cutting with extended and large tools.
            b) Multiple use of misaligned automatic tool changer.
            c) Dirt and chips getting on taper surface.
A Simple Test
    Here's is a quick test you can perform yourself to determine whether or not your
    spindle needs grinding:

            a) Take the suspected tool and holder.
            b) Wrap three short pieces of 1" masking tape evenly spaced in three places           
    around the large end of the tool taper ( without overlapping or creasing ) and make a
    trial run. Move the tool away in "Z" axis to avoid under cutting.

    If this helps any one of the above causes you're in need of our service.