What tool for turning radius and balls

[Longhorn6120]

This question seems to go round and round on this forum...

Well judging from the title that’s only to be expected...

 

[123hotchef]

That's the dogs danglies for a manual lathe! I want one!

me too

 

[123hotchef]

In school we used worn out flat hand files to make a tool with a semi-circle profile to cut a ball shape on aluminium.

oh tell me more

 

[MattF]

oh tell me more

Profile cutter. Shape a half circle in a piece of HSS.

 

[123hotchef]

Profile cutter. Shape a half circle in a piece of HSS.

and hold it in a tool holder

 

[MattF]

and hold it in a tool holder

Yup. You've already created the shape you want in the cutting tool, so just feed it, steadily, into the metal.

 

[123hotchef]

Yup. You've already created the shape you want in the cutting tool, so just feed it, steadily, into the metal.

i have a few old files need to make one now and try it out! sounds like fun. just need to make it mountable into a QCTP

 

[MattF]

May be worth roughing out the shape on the workpiece as you normally would, first. It'll impose less strain on the lathe & cutter than feeding into a blank. Just remove some excess metal, so to speak.

 

[123hotchef]

May be worth roughing out the shape on the workpiece as you normally would, first. It'll impose less strain on the lathe & cutter than feeding into a blank. Just remove some excess metal, so to speak.

good idea still playing with the idea

 

[citizen kane]

This is my version of a ball turner, not sure what it came from originally, doesn't fit in a QCTP, in fact you need to remove the whole top slide to get it bolted down onto the cross slide, makes me scratch my head and gurn a bit trying to get it setup but once its dialled in it does the job just fine.

 

[123hotchef]

This is my version of a ball turner, not sure what it came from originally, doesn't fit in a QCTP, in fact you need to remove the whole top slide to get it bolted down onto the cross slide, makes me scratch my head and gurn a bit trying to get it setup but once its dialled in it does the job just fine.

View attachment 280916View attachment 280918

thats a big boy!

 

[Turbo]

oh tell me more

It's been 30 years since I last done it but its as Mattf said, grind your profile into the end of a flat file, grind back some relief on the cutting edge & away you go.

We ground them by eye but you could use a carbide hole saw to get a perfect circle.

Use a slow cutting speed & slow feed, files are quite brittle!