Somewhat bewildered [not only by Clarke’s price for the chuck]
The documentation shows three holes on the spindle nose plate … but the four-jaw has four fixings
… do they include an adapter plate, or is this just artistic license ‘for clarity’ ?
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Personally, I would be tempted to reduce the register diameter, to enable fitment of an alternative four-jaw, and then make a spacer ring [ like a circular-saw blade ‘reducer’ ] for the existing three-jaw.
MichaelG.
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P.S. ___ in my search for enlightenment, I found this video which you might find useful some time:
**LINK** https://youtu.be/XPpLGtzaErM
Edited By Michael Gilligan on 04/11/2020 09:40:07