Lathe Enhancements and modifications |
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Indexing on an old Graduate lathe.by Frank Clark RPTA 150mm diameter indexing plate drilled with three rows of holes of 24, 36, and 72 holes is available from David Peters, Doublesse House, The Drift, Exning, Newmarket, Suffolk, CB8 7EZ. The indexing plate is bolted to a 75mm diameter faceplate with a left-hand thread and fixed on the outboard end of the lathe. Accurate location of the holes required to be drilled in the indexing plate can be accomplished by clamping the plate on the spindle by screwing the faceplate on the spindle the wrong way round and spotting through the holes in the faceplate with an appropriate size drill. The detent plunger support is made from an angle bracket, bent up from 25 x 3mm mild steel, bolted to a length of 1in. diameter mild steel to fit in the outboard toolrest support. With the angle bracket resting on top of the outboard support it is marked at centre height for drilling for the plunger. Apiece of 12 x 20mm mild steel bar is fixed to the bracket at the plunger position and both are drilled for a 6mm diameter bolt. The detent plunger is made from a 6mm dia. bolt 50mm long with the end turned or filed to a taper to fit into the holes in the indexing plate. Pass the bolt through the mild steel block and angle bracket, slip a small spring over the bolt followed by a washer and nut. Adjust the tension by compressing the spring by tightening the nut. The plunger can be aligned with any row of holes by adjusting the toolrest support on the outboard platform.
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