You turn a piece in the lathe, then face it. Now you want to cut a circular groove in the face.
eg the blank for a myford-style gear wheel has a centre and rim of similar thicknes, but inbetween there is a thinner web - how would you cut that from solid?
What tools do you use?
sorry if this is obvious
Two options ..... one a D bit shaped tool and second a cranked round nose tool if you want a radius in the corner of the web. But with the cranked tool you need two, one of each direction for the outer radius and inner radius. There is a third option not to use the lathe but mill the groove on a rotary table leave the work in the chuck and mount the chuck on the rotary table so the work is not disturbed and the groove will be concentric with the bore and diameter.
Alan
A straight round nosed tool, probably ground with a little extra clearance to its left hand side, mounted pointing towards the face to be machined, will be better for this job as there will be no need to change tools and no risk of creating a step at the meeting point of the two cuts suggested.
You are not limited to bought pre-formed tools. I acquired a set second hand with my first lathe years ago, and have never bought any more. I always use HSS square section tool bits, and very recently a couple of indexable carbide tip tools. Any form-tool shape you require can be ground from an HSS tool bit.
The milling option is, well, lets say, perfectly possible.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.