How do you turn a wide slot precisely with a lathe ?

[compact8]

Do you use seperate right-hand and left-hand tool to cut each side and hopefully the diameter will be the same or use a single slotting tool that can cut in all directions ? Is there such a carbide tool for low-power hobby lathe ? Mine is Emco Compact 8

 

[Ken226]

I would use two tools. It shouldn't be difficult to determine the offset needed between the tools to get each to the same diameter in the bottom of the groove.

If your not confident you can hit it close enough, or a seamless surface finish is what you need, leave the diameter a couple thousandths oversize. Then grind a hss form tool, similar to a parting blade, but wide enough not to deflect.

Use the hss tool for the last couple thousandths.


Something like the 5th from the left.

 

[Chewy]

As Ken226 said above. Rough out the groove and leave maybe 10-12 thousands high. I use a 1/4" HSS tool that used to be a parting tool. Flat nose and the sides tapered back a couple of thousand. One day I needed a trepanning tool, so I rounded off the left side. Now I use it for trepanning and flattening out slots. Take a light cut and adjust as needed for a good finish.

 

[SLK001]

You don't tell us the width of the slot, which will determine what tools you will use. A very narrow slot will require a specially ground tool. A wider slot can be done many different ways,