Tuesday, March 8, 2011

Monty Remon’s Adjustable Height Toolpost

“Once I had seen a design for an adjustable height tool post I new I'd have to make one, the woodruff key design was ideal. I have reconstructed here with photos the operations I used to achieve my goal, hope it helps someone.
I used 1"x1/4" steel off cuts clamped in the tool post, this was used as the work holder and then this was mounted off centre in the 4J chuck. A radius of 0.75" was suitable for machining material 1/4" thick, (a piece of 1/4" brass has been substituted for illustration purposes.)
Method, cutting the external diam.. First, wind out the tool .75" from the centre, zero dial (note reading). Centre the tool post width in the 4J then offset with the other jaws and packing to bring the work piece up to the tool bit. Now crank away from the work, and check everything is clamped tight. 3/8" of cutting will allow enough metal to part off with a saw later. I took 5 thou cuts and was down to the surface ( ZERO/.75" rad.,) in no time. Change your tool bit now for a thin internal cutting one and wind it OUT until the cutting edge aligns with the external surface you have just machined. Slide the tool holder out of the chuck. Remove the woodruff piece and the 2 tool post screws. Mark a line on the face of the tool post 1/4" below the normal tool bit seating. Slip the tool post back in the 4J and wind the jaws until the scribed line comes up to the cutting edge of the tool bit, clamp everything again with padding. Now do the internal boring, here the radius of the cut takes president over the depth (1/4") of the cut, the inside edge of the tool bit will catch the top of the tool post slot if you get this wrong. Set the depth stop and remove metal until you 'zero'. Theoretically both machined surfaces will have the same curvature. Saw your woodruff seating turning off the stump, you could now clamp this back in the tool post and face the edge. This has been harder to describe than to make!”


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