A few days ago I posted a question about how to cut the face groove on this part of the Quorn Mk3 I'm building
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There were plenty of suggestions including making a trepanning tool, purchasing a face grooving tool or making a multi-tooth cutter like a hole cutter.
I tried making a trepanning tool but by the time I had ground the necessary relief on the 1.6mm wide, 4.9mm deep tool, there was almost nothing left and it snapped immediately. I do not have the necessary grinder to make a curved trepanning tool. Commercial tools are available but £100 to cut a few grooves was not justifiable. I also did not have a piece of silver steel of the right size to hand to make the 'hole saw' type tool. I therefore arrived at another solution.
I've got a 'Quick Step' toolpost mounted milling attachemnt and set this up in the lathe as so..
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The chuck was set rotating at 20rpm and the 1.6mm slot drill was running at 4000rpm. The carriage feed was set to 0.04mm/lathe revolution.
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Worked rather well. The 4.9mm depth was reached without misshap on both parts.
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Resulting slot was almost exactly to the specified 20.6mm i.d.
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This is the first tme I have used the Quick Step in this way with the workpiece rotating but seemed to work. Result !