Looking for a fine point insert tool for turning the back side of a Ball

[GreensandsParticipant @greensands]

After trying out several techniques for turning ball shaped objects on the lathe using the traditional method of coming in from each side of the ball I have recently seen a video where the ball in question is being turned from the free end. Obviously the geometry of the ball is a major factor here but is anyone aware of any suitable finely pointed insert tooling which might be worth exploring. Inserts available from the usual suppliers do not seem to include the finely pointed patterns

[GreensandsParticipant @greensands]

[old martParticipant @oldmart]

I have a toolholder for VCGT 16 which is too sharp tipped for normal use. The inserts for it are so sharp tipped that I used them for drag engraving the new cross slide dial for the lathe. The toolholder is 20mm which might be too big for you, but there might be 16mm to fit that size of insert. I think the tip radius might be 0.25mm. There are several sizes of VCGT inserts on ebay.

Edited By old mart on 14/12/2020 20:38:05

Edited By old mart on 14/12/2020 20:44:10

[GreensandsParticipant @greensands]

Yes, that is certainly the stye of insert I have in mind but having a Myford lathe I would be looking for ideally a 10mm toolholder or perhaps 12mm at most.

[DiogenesIIParticipant @diogenesii]

JB Cutting Tools do 'em.. 10 or 12mm shank for 11mm insert

SVJCL 11 Indexable turning tool

..check which 'hand' you need..

Edited By DiogenesII on 14/12/2020 20:55:30

[Howard LewisParticipant @howardlewis46836]

The pictures show exactly the type of insert used on the Repton Ball / Radius Turning tool.

They work extremely well, in my limited experience

Howard

[old martParticipant @oldmart]

You would need a left hand tool that uses size 11 inserts. Those that I have, came with a job lot and have an insanely sharp tip, that is why they are more use for engraving lines than turning. I also have other variants with larger radius tips which are more useful for turning.

This site is worth bookmarking for understanding carbide inserts:

 

http://www.carbidedepot.com/formulas-insert-d.htm

Edited By old mart on 15/12/2020 14:24:26

[GreensandsParticipant @greensands]

Some very useful info here. Thank you for all the help provided

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