Hi Guys,

I had to make some new soft jaws for the lathe chuck, the old ones had been turned out quite a lot and I could no longer hold small diameters. I need to be able to hold and machine a M8 brass bolt in order to use it for another job.

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Here you can see the new soft jaws in use ! They just need the face of them skimming so that they are true. You can see the scratches on two of the jaws showing that one jaw is slightly lower than the others. The M8 bolt has been held in the jaws and the head has been turned off. The soft jaws were drilled out to 8 mm. The brass piece in the jaws is for a piston rod coupling link.

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I cut three strips of 16 mm thick aluminium plate to 15 mm wide. Which were then shortened to 60 mm long. I then cleaned up the cut edges on the mill. Then sat them cleaned faces down onto a hardwood block so that I could clean up the other edge and take them down to 14 mm thickness.

Setting a stop on the milling vise and using the DRO to set the drill 10 mm from the end, I drilled a 6 mm diameter hole 10 mm in from one end on all three pieces. I then moved by 17.50 mm to drill the second hole.

Note that I already knew the hole distance from the original drawing.

I then set up the bandsaw to cut at 45 degrees. Really should have been 60 degrees but for these parts it doesn't matter and I already had an index for that angle. I set a length stop on the bandsaw and cut all six faces.

Then using the drill press I counter sunk all six holes to 10.50 mm diameter so that the counter sink heads of the M6 screws were flush or just below the surface. This is done so that the screw heads do not catch the lathe tool when truing the jaw faces.

When machining the soft jaws for a particular size you need to use something inside the jaws so that they cannot move, otherwise you may not get a true bore size.
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